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General Discussion => Advanced Concepts => Topic started by: josh_simonson on 11/19/2006 12:46 AM

Title: Fusion with space related aspects thread
Post by: josh_simonson on 11/19/2006 12:46 AM
<p>Here's an interesting lecture at google last week about a different means of achieving fusion than the typical tokamak. This work was recently declassified when the navy's long horizon energy research programs were cut (of which this was one). Interestingly, they transfered the lab equipment to SpaceDev where it's being babysat while alternative funding is being arranged. Near the end Bussard talks about applications as a space engine.</p><p><a name="Video">[/url]http://video.google.com/videoplay?docid=1996321846673788606 </p><p><a title="Google video" target="_blank" href="http://video.google.com/videoplay?docid=1996321846673788606"> [/url] </p><p><font size="-1">Google Tech Talks November 9, 2006
</font>
<font size="-1"> ABSTRACT This is not your father's fusion reactor! Forget everything you know about conventional <span class="invisible" /><span class="visible">thinking on nuclear fusion: high-temperature plasmas, steam turbines, neutron radiation and even nuclear waste are a thing of the past. Goodbye thermonuclear fusion; hello inertial electrostatic confinement fusion (IEC), an old idea that's been made new. While the international community debates the fate of the politically-turmoiled $12 billion ITER (an experimental thermonuclear reactor), simple IEC reactors are being built as high-school science fair projects.

Dr. Robert Bussard, former Asst. Director of the Atomic Energy Commission and founder of Energy Matter Conversion Corporation (EMC2), has spent 17 years perfecting IEC, a fusion process that converts hydrogen and boron directly into electricity producing helium as the only waste product. Most of this work was funded by the Department of Defense, the details of which have been under seal... until now.

 Dr. Bussard will discuss his recent results and details of this potentially world-altering technology, whose conception dates back as far as 1924, and even includes a reactor design by Philo T. Farnsworth (inventor of the scanning television).

Can a 100 MW fusion reactor be built for less than Google's annual electricity bill? Come see what's possible when you think outside the thermonuclear box and ignore the herd.</span></font></p>
Title: Re: Fusion with space related aspects thread
Post by: TyMoore on 11/19/2006 04:23 AM
Inertial Electrostatic Fusion and the Farnsworth "Star" Fusor have actually been used for decades in the form of small portable neutron generators. The bursts of fusion neutrons are actually generated in a vacuum tube loaded with a small amount of deuterium and tritium gas. The Fusor lies at the center and the electrostatic grid is charged to some thousands of volts positive to accelerate the positive ions toward the geometric center--as the ions oscilate through the center, some of them collide with sufficient energy to fuse.

See:

http://www.farnovision.com/chronicles/fusion/vassilatos.html

A nice description on how to actually build one of these devices is available at:

http://www.belljar.net/634fusor.pdf

Here is a nice piece on the Farnsworth Fusor:

http://fti.neep.wisc.edu/iec/AmericanScientist.htm

The device can produce powerful bursts of neutron radiation useful for downhole detection petroleum deposits in the oil business and in certain kinds of biological imaging, but the amount of fusion going on is measurable in terms of picowatts to microwatts.  It cannot produce much more than--and in any case, such devices are extremely dangerous because of the penetrating nature of the neutrons.  Full body neutron exposure can be quickly fatal, and with a machine that can produce KiloHertz bursts of 10^9 to 10^10 energetic neutrons each burst (this translates to a neutron fluence of 10^18 to 10^19 neutrons per second!) Still, such devices do not scale up millions of times well, and cannot produce millions or billions of watts needed for something like a powerplant. It is interesting physics, but it is not a power generating machine....
Title: Re: Fusion with space related aspects thread
Post by: meiza on 11/19/2006 01:32 PM
Could these devices store antimatter too instead of magnetic confinement?
Title: Re: Fusion with space related aspects thread
Post by: TyMoore on 11/19/2006 02:12 PM
Not very much and not efficiently--because the particles would tend to oscillate through the center the probability is very high that they will eventually collide with the accelerating grid. Because one cannot physically make an infinitely thin accelerator grid, then dissipative losses will prevent long confinement times. This is one of the reasons why inertial confinement fusion is limited to small scales, and why a similar device cannot be used to store antimatter. The only way around that limitation is to create a 'virtual' cathode--but that requires application of some really tricky physics that deal with radio-frequency induction, ion cyclotron heating, and these resonances are not the same as the ion resonances exhibited by the IEC Fusor... so you end up with a completely different device anyway...
Title: Re: Fusion with space related aspects thread
Post by: josh_simonson on 11/19/2006 05:54 PM
These guys are using the same principle of electrostatic confinement, but a much different means to go about it than Farnsworth.  Watch the video, it's quite interesting.
Title: Re: Fusion with space related aspects thread
Post by: PurduesUSAFguy on 11/19/2006 08:59 PM
I guess the main question in my mind is how do you convert the reaction in an IE containment fusion device into useable power? It seems like engineering a pressurized water loop through such a device would be difficult and I don't think you could use MHD coupling with Boron-Hydrogen fusion, although I don't really know...

It's an interesting concept, and I hope it works, but so many have worked so long on fusion that I tend to be very skeptical of anyone who has 'figured it out' outside of the established plasma physics community.

That being said I do think that the answer to commercially viable fusion is something 'out of the box' and that ITER isn't the road to fusion power. I think we need to focus more on novel devices like Princeton’s near spherical tokomak and basic plasma physics.
Title: Re: Fusion with space related aspects thread
Post by: mong' on 11/19/2006 10:39 PM
What I am wondering is: how difficult is it to build a fusion rocket (i.e: that is supposed to leak some plasma out the back) compared to an electricity producing reactor ?
it would seem that a thruster would be easier because you don't have to worry about producing more power than you need, no complex energy conversion mechanisms and since you want to eject some of plasma the leakage problems are somewhat mitigated.
whadya think ?
Title: Re: Fusion with space related aspects thread
Post by: meiza on 11/20/2006 12:01 AM
You still need to transfer the energy to a working fluid... Unless you use it as a in-space drive where high thrust is not necessary.
Title: Re: Fusion with space related aspects thread
Post by: mong' on 11/20/2006 11:11 AM
yes that's what I am talking about, an in space propulsion system, low thrust/very high ISP expelling only the charged fusion products throuh a magnetic nozzle.
although it would be a good idea to increase thrust with a working fluid, even if it decreased the ISP significantly, it would still be very interesting
Title: Re: Fusion with space related aspects thread
Post by: Marcus on 11/20/2006 07:26 PM
Quote
PurduesUSAFguy - 19/11/2006  1:42 PM

I guess the main question in my mind is how do you convert the reaction in an IE containment fusion device into useable power? It seems like engineering a pressurized water loop through such a device would be difficult and I don't think you could use MHD coupling with Boron-Hydrogen fusion, although I don't really know...

Way back in my early undergrad years I was working with a professor who did some of the more out there propulsion research at Purdue. It was the guy who's concentrated-Hydrogen-Peroxide-soaked cabinets set his room in the ASL on fire in the 2000 time-frame (that was an exciting day at the lab, let me tell you)

Along with his real research, he engaged us Aero and Nuke undergrads in our pie-in-the-sky theoretical research projects (read: fantasies). The one I was working on was a spacecraft powered by a pair of IEC's using direct energy conversion to siphon off about 5-10% of the power from each reactor. We were trying to scale up a small propulsive effect observed when some conducting geometries were energized using 50,000 volt capacitors. It turned out that we were just seeing an ion wind effect due to our inability to pull a good vacuume in our leaky bell jars. Anyway, the point was that the Nukes were convinced that they would be pulling Megawatt-type power from a 3mX3m self-sustaining IEC box using 5-10% efficient direct energy conversion. No indirects or anything (because we didn't have room for the thermal cycle stuff onboard our spacecraft.) This miraculous breakthrough was, at the time, 10 years away. Which, today, would make it--in the nature of all fusion applications--about 10 years away. :p :p

Haha, I remember working on the airframe for the "spacecraft". Initially it started out looking like the teardrop-shaped silver thing from "Flight of the Navigator" thanks to the propulsion system, but the radiator surface necessary for the IEC's kept growing until we started referring to it as "Hell's Butterfly." We thought we'd be launching from the ground, but considering the massive voltages we were working with, I think it would have been more likely to find gainful use as more of a giant bug-zapper than an actual spacecraft. Maybe we could've convinced the Japanese they needed it to kill Mothera or something. :)
Title: Re: Fusion with space related aspects thread
Post by: PurduesUSAFguy on 11/20/2006 08:10 PM
That's pretty cool Marcus,

Speaking of Purdue I'm just glad Armstrong hall is about to Open, Aero E has needed a better building then Grissom Hall for a long time now...
Title: Re: Fusion with space related aspects thread
Post by: Marcus on 11/20/2006 08:57 PM
Quote
PurduesUSAFguy - 20/11/2006  12:53 PM

Speaking of Purdue I'm just glad Armstrong hall is about to Open, Aero E has needed a better building then Grissom Hall for a long time now...

I dunno. I sort of liked the distinction of being the best students in the worst building. Well, I guess the old art school qonset huts were worse, but Aeros are still better.

When is Armstrong hall opening, and who is going to be in there? I'll be back for Xmas and I'd like to check it out. I was thinking about going for back for a MS in about 2 years, either Aero or Nuke. It'd be cool if they put the Nukes and Aeros together. After all, Aero/Astros have more in common with Nukes than they do with IEs, and the ME's already have their own building. Then again, I enjoyed raiding the IE's clubs' meetings for pizza and then retreating back to the Aero lounge.
Title: Re: Fusion with space related aspects thread
Post by: PurduesUSAFguy on 11/20/2006 10:05 PM
Well Armstrong Hall was supposed to be AAEs only but last year they switched from Hall of AAE to Hall of Engineering...I heard that they might be putting the soon to be established nano-tech program in there with us.../shrug/.

It wouldn't shock me if a couple nuke classes didn't find there way into there as well as Nuke is kind of stuck in the corner behind the engineering mall behind the Tech building.

I think its supposed to open first semester of next year, but it looks pretty close to done right now.
Title: Re: Fusion with space related aspects thread
Post by: Marcus on 11/20/2006 10:39 PM
As long as they bring their reactor with them. *Fiendish laugh*  
Ya know, all 1 kW of it.
Yeah, I had to go back there to talk to a prof about my senior project. That's what got me interested, actually. If you don't mind me asking, do you work at Purdue, or student?
Title: Re: Fusion with space related aspects thread
Post by: PurduesUSAFguy on 11/20/2006 11:39 PM
Student, double major in AAE and Nuke-E actually...although one of those might turn into Physics.
Title: Re: Fusion with space related aspects thread
Post by: Marcus on 11/21/2006 02:49 PM
Quote
PurduesUSAFguy - 20/11/2006  4:22 PM

Student, double major in AAE and Nuke-E actually...although one of those might turn into Physics.

USAF ROTC?

That's quite a load. How many years are you trying to squeeze that into? Have you had any KC Howell courses yet?

How do you like the Nuke program? I had limited contact when I was a student, but now I've a decided interest in NTR. Any Nuke profs interested in NTR or even space power/NEP? When I was around, the focus seemed to be on civil reactor safety and some theoretical particle physics that wasn't of much interest to me. If you know of anyone interested in something not ground-or-navy-bound, could you let me know. You can send me a private message if you want. I'd like to get in contact with them. A name would be enough.

Thanks.
Title: Re: Fusion with space related aspects thread
Post by: Ventrater on 11/21/2006 10:24 PM
IEC or focusfusion?
http://focusfusion.org/log/index.php/site/toc/what/
Title: Re: Fusion with space related aspects thread
Post by: HD209458 on 11/30/2006 04:00 PM
Back on topic a little bit; it has always been my impression that IEC fusion like this was useful as a neutron source, but not for power generation (or propulsion). IIRC, Bussard's main claims about the power of his machine were denominated in neutron counts, which seemed to me to support this view of IEC as primarily a neutron source.

Do the nuclear enginners here know if this is true? Or is Bussard et. al doing something different, that is causing his machine to generate power?
Title: Re: Fusion with space related aspects thread
Post by: josh_simonson on 11/30/2006 07:49 PM
Here's a letter Bussard wrote that is basically a condensed version of his google speech, without all the cool photos and history.

Appearantly it's not a Farnsworth derivative, from the final P:
"One final word: Actually our device is really not a variant of Farnwworth/Hirsch, but of Elmore/Tuck/Watson who propeosed the inversion of Farnsworth/Hirsch long ago (ca. 1967). Their problem was the interception of circulating electrons by grids - we removed the grids and replaced them by B field insulated coils - thus our "grids" are the coils themselves."



Dear SirPhilip!:

I have read the threads on the Randi forum, and they are all intent and I am sure well-menaing. However, I have not been able to "log in" on this forum so am writing to you instead. Perhaps you can post this note as a reply and commentary to some of the issues raised by your forum correspondents.

First, what we have achieved in our rather unexpectedly good tests of last November 9 and 10th was an output of DD fusion at about 10 kV, at B fields of 1300 G, in a 30 cm diam device (WB-6) run in a pulsed mode from big capacitors, with a fusion rate of about 1E9 /sec. This works our to be about 100,000 x higher than the data of Hirsch/Farnsworth at similar well depth and drive conditions. The test duration was only about 0.4 masec, but since the electron lifetime is ca 0.1 microsec this is steady-state to the plasma particles. We had neither the money, nor the cooling, nor the power supplies, nor the controls to run this small device steady-state, which is what we need to do, and what requires us to build the full-scale device.

This was a direct result of discovering something during late Spring/ early summer tests of WB-5, which was a closed boc machine, like the early HEPS of 1989. What we discovered was -- in hindsight -- elementary; it was that indeed God is in the details, and the detail of particular importance is that no metal surface penetrated by B fields must occupy more than about 1E-4 to 1E-5 of the total surface available to the recirculating electrons. If this dead fraction is larger, there is NO hope of net power from any such machine. AND, it is essential that the device be recirculating, i.e. that the electrons can circulate out and back through the cusps all over the machine. Of course, this is obvious; but in 15 years no one saw it, not Hirsch, not our consultants not our opponents, not our staff, and not me.

It is consistent with the need for electrons to recirculate about 100,000 times before being lost to collisions with structure, to yield net power.

Please remember that our device has the property that the electron flow and losses are decoupled from the ion flow and fusion generation. Power balance depends on suppresssion of the electron losses, which are derived from the energetic electron injection that forms the gridless negative potential well that traps the ions.

When we figured this thing out, in summer 2005, we quickly designed and quickly built WB-6, using only conformal (with the B fields produced) coil cans, so that no B field uniquely penetrated the cans, and then placed the coils in a special array so that no corners touched (this latter is a long topic having to do with local B fields, and loss of WiffleBall trapping due to line cusp effects at the corners, etc, etc, and is the baisis of our final patents on this thing). It IS the details that make or break the device. And this particular set of details absolutely dominates the performance.

Anyway, we ran the device in October, for beta=one tests, to confirm transport scaling laws, and then in early November to test for fusion output. And, happiness, indeed, three tests on 9 November and one on 10 Novem,ber gave the results mentioned above. The next day, 11 November, we tried it again, but magnet coil motions induced by repeated testing had moved the coils enough that an insulation spot had worn away inside the cans, and the device shorted and blew up one leg, with the full cap discharge. Having no further funding, we had to start shutting doen the lab the following Monday!!! Irony?

As to our funding -- our USN contract still exists, and still has about $ 2M authorized in it. However, year-by-year funding was NOT provide for FY 2006, so that we knew we had to close down early in 2006.. What saved us was Adm Cohen (CNR) who put another 900 K into the program to try to get us down the road to where we DID go, and then we had to quit. It was not a cutoff of OUR funding, but the entire Navy Energy Program was cut to zero in FY 2006, and we were a part of this cut. The funds were clearly needed for the more important War in Iraq.

So, as we cut down, we managed to save the lab equipment, by transfer to SpaceDev, which hired our three best lab people as well, and we are still trying to get the missing $ 2M restored and put into our existing but unfunded contract. IF this happens - which is improhable, given the politics of this election year, and the non-visionary people in Congress - we will redo WB-6 with an improved and better version (WB-7) which should give 5x more output, and run about 50 tests to quiet dissent. AND we will convene a review panel of very high-level and internationally distinguished people to spend about 6 weeks going over this to recommend for or against proceeding sith a full scale demo.

This may or may not happen. If it does, I have little doubt as to the panel recommendation, as the data and insight from WB-5/6 is just too clear. We really have solved the last engineering physics problem that has plagued our work for 12 year s or so. Yes, there is much left to do, iespecially in controls and diagnostics, but these are predictable things not dependent on beating the Paschen curve.

And we still have to develop some reliable e-guns and i-sources, again predictable enginering that costs both time and money, but not new physics.

Why a full-scale demo? Because the system scales oddly: Fusion output goes as the 7th power of the size and Gain goes as the 5th power. Thus there is very little to be gained by building a half-size model; it is too weak to give anything definitive about power production or gain. And our tests were always at about 1/8 to 1/10 scale of the full scale demo. We told the DoD from the beginning that the real program would cost about 150-200 M, since 1987, and they all knew this. However, since the DoD has no charter to do such work, and the political realities were that a big DoD program would attract the ire and power of the DoE to kill it, it was never funded beyond about 1/8 the level required.

So we did what we could and finally DID prove the physics and associated engineering physics constraints, scaling laws, etc, albeit at 1/8-1/10 scale. So what? Doubling the size will not tell us anything we don't already know. The next intelligent and logical step is to build a machine big enough to make net power. And THAT is the same 200 M we have quoted to the DoD since the beginning.

As for energy companies "stampeding" to support us -- It is clear that a view like this is ignorant of the reality of energy companies. There is only one thing the oil cvompanies want, and that is to sell oil, and more oil. So long as the fields pump, the oil companies will squeeze. They have NO, absolutely NO interest in anything new, ins spite of all their foolish ads in magazines for wind mills and solar-PV roofs. It is all just show and tell. I know these guys, and there is no way they would support anything that might get in the way of oil. The only way to stop oil, from their view, is when it does run out. And then they''ll go for deeper drilling, new fields, Gulf geopressure gas, LNG, etc, etc, and keep raising the price, until finally foolish solar and windmills become competitive.

And we are paying the equivalent of $ 500/bbl oil costs. But Exxon and Halliburton are getting richer all the time.

Yes, we would like to build the demo plant, and yes, it will cost about 150 (DD) to 200 M (pB11), and who knows if any investor singly or a group can or will come up with the money. One of the biggest obstacle is the world-wide tokamak lobby, which perpetuates the fraud that Hirsch, Trivelpiece and I foisted on the country in the 1970's when we started the big tokamak ball rolling.

Magnetic confinement fusion is a misnomer, as magnetic fields can NOT confine a plasma, only constrain its motion towards walls. The entire history of the MagConf program has been to reduce transport to neo-classical (not turbulent or instability-driven) losses. And THEN the machines are all inherently and inevitably huge and cost too much and make too much power to ever be economically useful --- as the utilities have been telling the AEC/DoE for 30 years. No matter, the global tokamak program provides jobs for hudreds of thousands of people in many countries, and is a safe place to put political pork funding, simply because it IS NO THREAT TO OIL - it won't ever work, but it sounds good to the untutored public..

As for us; our company still exists, but we will not likely run any demo program - that will be up to others to carry it on, if we all get the chance. Meanwhile, my objective is very simple. I detest the energy stranglehold of our companies on our people, and am going to try to give our idea away at the soonest possible moment. To anyone, anywhere, who might want to undertake its development. And we'll be happy to help in any way we can, if a serious interest develops anywhere in the world.

I think the US, UK, France, et al are lost causes, because of theri commitment to the failed tokamak effort, as is probably Germany, and maybe others, too. China may be a possibility, as it is quite independent even though part of the ITER mess, Russia may be considererd, and countries like Spain, Brazil, Italy, Argentina, and others may logically have an interest.

I believe that the survival of our high-tech civilizations depends on getting off of fossile fuels ASAP, and - if we do not - we will descend into a growing series of "oil wars" and energy confrontations that can lead only to a huge cataclysim. Which CAN be circumvented if only we build the clean fuison machines in time. Our patents are in final form, and I am giving a paper in the Fall, and trying to get a large technical description together for a major paper by summer. We shall see.

One final word: Actually our device is really not a variant of Farnwworth/Hirsch, but of Elmore/Tuck/Watson who propeosed the inversion of Farnsworth/Hirsch long ago (ca. 1967). Their problem was the interception of circulating electrons by grids - we removed the grids and replaced them by B field insulated coils - thus our "grids" are the coils themselves.. And we do know how these work, at last.

Good luck to all of us.

Cheers, RW Bussard
Title: Re: Fusion with space related aspects thread
Post by: braddock on 12/01/2006 12:40 AM
This is a very interesting video.  I'm skeptical of the potential, but regardless I just learned an awful lot about interesting fusion devices while watching.

There is a fairly critical critique of the presentation here:
http://futurepower.org/nuclear_energy_experiments.html
Don't know how much credence to give the critique or the presentation, but I found both interesting.

Does anyone have links to the "8 or 9 papers" he mentions that discuss using their fusion technique for space travel?
Or the main lessons learned paper he mentioned that was to embody his lessons learned in the astronomical proceedings?
Title: Re: Fusion with space related aspects thread
Post by: PlanetStorm on 12/01/2006 09:10 AM
Quote
HD209458 - 30/11/2006  4:43 PM

Back on topic a little bit; it has always been my impression that IEC fusion like this was useful as a neutron source, but not for power generation (or propulsion). IIRC, Bussard's main claims about the power of his machine were denominated in neutron counts, which seemed to me to support this view of IEC as primarily a neutron source.

Do the nuclear enginners here know if this is true? Or is Bussard et. al doing something different, that is causing his machine to generate power?

The thingt he is doing that is different is that he has reduced losses by an enormous factor. By removing the grid, or more accurately, by shielding the grid with magnetic fields, he keeps the electrons from hitting absorbers and so they can cycle 100,000 times.

The neutron count thing is a red-herring. In the demo devices, he deliberately used "fuels" that generate large neutron fluxes because the neutrons provide such a good diagnostic that fusion has actually occurred. Utlimtately, though, his goal is to use boron fuel and essentially eliminate neutron production altogether. This would be perfect for energy generation but not much good in his small scale demo devices because, as the gain is so small (remember he says that gain scales as size ^ 5), there would be no detectable energy production and hence no way of knowing that fusion has occurred.

If I had 200 million to spare, I would seriously consider giving it to him!

Title: Re: Fusion with space related aspects thread
Post by: PlanetStorm on 12/01/2006 09:13 AM
Quote
braddock - 1/12/2006  1:23 AM

This is a very interesting video.  I'm skeptical of the potential, but regardless I just learned an awful lot about interesting fusion devices while watching.

There is a fairly critical critique of the presentation here:
http://futurepower.org/nuclear_energy_experiments.html
Don't know how much credence to give the critique or the presentation, but I found both interesting.

Does anyone have links to the "8 or 9 papers" he mentions that discuss using their fusion technique for space travel?
Or the main lessons learned paper he mentioned that was to embody his lessons learned in the astronomical proceedings?

I don't think that critique shows any insight into the potential of the device. Mostly psychobabble IMO.

Title: Re: Fusion with space related aspects thread
Post by: braddock on 12/01/2006 09:46 AM
The critique was sobering counter-balance, although I think it was a little too critical of him personally -- it's not like Robert Bussard isn't a world famous physicist already (Bussard Ram Jet, Asst Director of Atomic Energy Commission, etc).

The problems I have with the presentation are:

1) No energy accounting presented - the magnetic fields would presumably take much more energy than the old grid approach.  Where is break-even?

2) No cost proposal presented - in fact he mentioned that his cost slide was from 1994, complete with old crossed out prices and penciled in new ones!

3) A quarter of a millisecond reading of unexpected peak neutron emissions just before the prototype blew up and they shut down the lab - not exactly good scientific proof there.

4) He needs to publish everything.  Anyone who fully funds him on a $200 million adventure without a few years of peer-review publication is crazy.

By all means, someone give him $2 million to prove what he thinks he has achieved.  That is all he says he wants to continue research for one year ($5 million to ramp up the scale more quickly).  But he only mentions the $2 million in the Q&A afterwards...
Title: Re: Fusion with space related aspects thread
Post by: PlanetStorm on 12/01/2006 10:42 AM
Quote
braddock - 1/12/2006  10:29 AM

The critique was sobering counter-balance, although I think it was a little too critical of him personally -- it's not like Robert Bussard isn't a world famous physicist already (Bussard Ram Jet, Asst Director of Atomic Energy Commission, etc).

The problems I have with the presentation are:

1) No energy accounting presented - the magnetic fields would presumably take much more energy than the old grid approach.  Where is break-even?

2) No cost proposal presented - in fact he mentioned that his cost slide was from 1994, complete with old crossed out prices and penciled in new ones!

3) A quarter of a millisecond reading of unexpected peak neutron emissions just before the prototype blew up and they shut down the lab - not exactly good scientific proof there.

4) He needs to publish everything.  Anyone who fully funds him on a $200 million adventure without a few years of peer-review publication is crazy.

By all means, someone give him $2 million to prove what he thinks he has achieved.  That is all he says he wants to continue research for one year ($5 million to ramp up the scale more quickly).  But he only mentions the $2 million in the Q&A afterwards...

Give him a break, he had only one very rushed lecture in which to present a decade of work: you can't blame him for not filling in all the details, and he wasn't trying to build a full buisiness case, just outline the technology and its potential.

But in detail:
(1) energy accounting was covered in essence by the scaling law for gain and fusion output.

(2) He outlined his development plan and the funds needed, in as much detail as could be expected in the time allotted. Besides, he is clearly a physicist and his time is best spent doing physics - leave the bean counting to someone else!
 
(3) Where else are the neutrons going to come from? Also, evidence for fusion was obtained from two runs, if I understood him right. Wish I had been there to ask some questions though.

(4) Of course no one is going to give him 200 million right of the bat. I think he should rebuild his old 1/8 scale device and run some more tests, just
to counter worries like your point (3), and this looks like it could be done for a few million. He naturally wants to go to full scale device with continuous operation as the next step because he is convinced that there is nothing else to learn from small devices, but that is the only major problem I have with his argument. My other major problem is that I don't have a few million to give him!


Title: Re: Fusion with space related aspects thread
Post by: josh_simonson on 12/01/2006 08:16 PM
As I understand it, Google's 'foundation' for philanthropic purposes is not a 'non-profit' organization - when it can it is supposed to actively attempt to make money by helping people.  Long-shot, high payoff technology investments such as this are the ideal of philanthropy with such a mindset.  

It is suspicious that they pulled a rabbit out of the hat in the last hours of funding, that's the main concern I'd have.  

He seems to believe that there's a tokamak conspiricy wherein the fusion community will work to quash his research because it threatens the tokamak workforce (reminicent of shuttle workforce problems in NASA).

There's a petition online for congress to restore funding to this research, and $2m isn't all that much, I can't imagine him having to talk to too many billionaires and foundations that are hostile to the energy industry to find someone willing to fund or partially fund this work - especially considering that success could make them multi-billionaires.
Title: Re: Fusion with space related aspects thread
Post by: PurduesUSAFguy on 12/02/2006 08:27 PM
Well there is no doubt about what he says in refrence to their being a tokomak '(sorry, need to stop here for a second and just say that I have to use stupid words to get my point across. I know that means I must have a weak argument, but that's why I use bad words).'. There has been so many physicist who have staked their carreers on toridal magnetic confinement that there is an ingrained bypass in the plasma physics community against any nonconventional containment method.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 12/14/2006 09:04 AM
Robert Bussard not only concieved of a fusion ram jet rocket. He designed and tested the first US fission rocket. It is kind of sad that this genius is not more well known. Here is an article that Tom Ligon wrote about his work just before it went under wraps. It makes you wonder what else the DOD has cooking in some closet.


http://web.archive.org/web/20011213171457/http://torsatron.tripod.com/fusor/fusor.html


Here is the only post Brussard has made on the fusor.net page.

http://www.fusor.net/board/view.php?site=fusor&bn=fusor_announce&key=1143684406

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/23/2007 10:13 PM
Speak of the devil and in he walks.  Tom Ligon here.
A better copy of my December 1998 fact article in _Analog_ can be found at fusor.net, in their Newbie section.  It is called "The World's Simplest Fusion Reactor."  The other copies are pirated scans, no figures, and full of typos.

There's a lot of buzz on his October 2006 paper and the Google talk on this subject.  Links below include the talk, the paper, and a fairly new Wiki that I've been contributing to.

http://www.askmar.com/Fusion.html

http://en.wikipedia.org/wiki/Polywell

Goldin had something in the works, I can't find any references now, called "Strategy F", the idea being to get manned missions to Mars using fission or fusion propulsion.  The fission option was essentially NERVA, developed from Bussard's original fission rocket work (Rover, Kiwi-A).  The two fusion options were Bussard's electrodynamic p-B11 approach (see the paper linked at askmar) and the thought of strapping ITER on a rocket (hah!).

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 01/28/2007 06:12 PM
Tom!

Nice to see you here! What have you been up to lately? Looks like Bussard has gotten some international recognition for his work.

http://www.science.edu/TechoftheYear/TechoftheYear.htm

I have gotten an e-mail from Jim Benson that indicates that they don't intend to let Bussard's work lie fallow too much longer.  But Benson is still looking for big investors.

http://peswiki.com/index.php/Directory:Inertial-Electrodynamic_Fusion_Device
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/28/2007 08:26 PM
Yes, when Dr. Bussard had to close the lab, SpaceDev was kind enough to store the equipment and hire 3 of the people who made the thing work.  Jim would love to pick up the work an run with it.

I'm working for Athena Technologies on UAV control systems.  Morphing aircraft with LMA, Mars Flyer High Altitude Demonstration Drop, and neat stuff like that.  I just had a story accepted at Analog and am working on a sequel to "The World's Simplest Fusion Reactor."  Hopefully, by the time that publishes, somebody will have had the wisdom to fund this.

Looking at the data EMC2 produced, WB-6 ran at less magnetic field than any of the earlier models, and produced fusion as low as 5 kV, copious fusion at 12.5 kV.  Fusors don't generally make easily-detectable fusion on DD that low.  WB-6 is in a class by itself as IEC machines go.

Wikipedia also has an article and some discussion of this under PolyWell.  I contributed some to that.  http://en.wikipedia.org/wiki/Polywell

"The World's Simplest Fusion Reactor" was published with the intent of getting folks familiar with IEC, and getting some kids building them as science projects.  It begat an amateur fusion movement now centered around fusor.net, and to date 8 high-schoolers have made measurable fusion with Fusors, and two more are preparing to.  Michael Li won 2nd place in the Intel Science Talent Search in 2003 for his.

That wiki in your post has a couple of bugs that I've noticed so far.  The ions are actually "confined" by oscillating thru an electrodynamic potential well.  They are not affected significantly by the magnetic field.  It is the electrons creating the potential well that are confined with the aid of the magnetic fields, by virtue of the field both insulating the anode that accelerates them, and by formation of a trapping effect called a "wiffle-ball"

EMC2 started out in Manassas, VA, but has not been there in years.  The successes were in San Diego, and anyone wishing to contact Dr. Bussard at this time would use the Santa Fe address, or contact Jim Benson at SpaceDev.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/28/2007 09:23 PM
Tony,

To answer your questions posed under the Hawking topic ...

I worked for Dr. Bussard for about 5 and a half years.

Dr. Nicholas A. Krall has been working with Dr. Bussard on this essentially from the start.  His reputation as a theoretical plasma physicist is on par with Bussard's as a designer.

If I had 200 million and enough left over to live on comfortably, this thing would be funded already.

Bussard's approach is essentially a "perfect Hirsch/Farnsworth Fusor".  It is a spherical convergent focus electrodynamic particle accelerator.  It doesn't work on maxwellianized heat, it works by raising ions to fusion velocity and focussing them on a central convergence point.  Ions not making fusion collisions recirculate, and those making elastic non-fusion collisions have their energy re-equalized by a collisional phenomenon that occurs near the outside of the potential well.  The result is long ion lifetime at high kinetic energy.

I have a little Hirsch/Farnsworth fusor that puts out 3000 fusions per second at 18 kV on DD.  At 12.5 kV, the highest drive voltage WB-6 was run at, most fusors put out so little you have to beat the counting statistics to death to even detect the output, but WB-6 actually put out (for about a quarter of a millisecond at a time) a screaming load of neutrons.  Yesterday I read a report that noted that one of the tests was actually run at 5 kV and produced a neutron count (26000 fusions per count) in the 1/4 millisecond or so that the deep potential well existed.  Realizing that the statistical significance of one count is +/- 100%, it still floored me.  NOBODY does DD fusion at detectable levels at 5 keV.  The reason it could happen is that the machine naturally produces head-on collisions at fusion energies in the region around the central convergence point.

I'm not at all worried by the fact WB-6 was a pulsed machine.  I built and ran the smaller WB-3, which was perfectly capable of running essentially continuously at about 1/2 of the WB-6 parameters.  Correctly built, larger machines should be able to run continuously.

The scaling formulas for output tend to go up as B^4R^3, and gain goes up at B^4R.  Bussard expects B to scale with R, which is probably a gross under-estimate once you get into the superconductingmagnets he intends to use.  WB-6 ran most of its successful tests below 0.1 T.  The scaleup he wants to do for p-B11 is from R of 0.15 meters (WB-6) to R of 2 meters.  ITER recently tested one of their magnets at 13 T, and I think 25-30 T is achievable.  If his output scaling is correct, even scaling up WB-6 to the larger sizes and fields suggests the thing is going to run, and WB-6 was almost certainly not running in an optimal fashion.

Unless he is missing something really important, the thing should work.   Most technical criticisms people have mounted of this thing wind up referencing a master's thesis by Todd Rider, and to the best of my knowledge, the points Rider raised have all been addressed.  Some were were wrong or not applicable to this machine, one important one the machine itself corrects via a collision mechanism of the ions near the MaGrid, one is insignificant with proper design.  The electron loss problem in cusps was essentially correct, but applies only to the HEPS-style machines.  The MaGrids (which WB-6 is) are immune to it because they recirculate electrons lost to the cusps.  And Rider never said it wouldn't work, he just hoped a way could be found to overcome the problems he felt he had detected.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 01/29/2007 04:58 AM
Tom,

Thanks for shedding a little light on this. I just can't figure out why more scientists and engineers are not interested. I can't think of anything that would improve the quality of life of the children of the world more. Maybe the press is gun shy from the cry wolf effect of cold fusion.

Bussard's own admission, that for years they padded the DOE budget of the Tokamak to siphon off a little for programs that might actually work, does not engender trust with the press and the lay public, I am sure. Do you know any of Bussard's lab people that are working with Benson? Has Benson started any work on rebuilding WB-6 or starting WB-7 or 8? Or is all the equipment still in mothballs?

Are Bussard and Krall still working on this with Jim Benson? What is Krall up to now? Do you know how to contact him? Why did Bussard say he needed a bunch of engineers trained in the "gaseous electronics" of the era of Langmuir and Tesla? Who does teach design of magnatrons and gyrotrons right now? Just what type of vacuum tube type equipment does he need? Why was Bussard stressing this?

Why is he calling it Magrid Transport? Can you describe this in more detail? Is he leaving out a bunch of details here to protect his work? I read something about Mu-metal being a magnetic shield material. Is Magrid Transport more than a simple magnetic shield? But I don't know anymore than this, can you expand on this?

The one thing Bussard seemed adamant on was that you couldn't make this smaller than a 2.5 meter cube. Why is that? Something nine foot on a side, seems like that puts it beyond the amatuer benchtop scientist. Is it? Has anyone on Fusor.net built ever super-conducting magnets?

"Realizing that the statistical significance of one count is +/- 100%, it still floored me." I don't undertand this.

I have talked to a Phd. in Fusion candidate at the University of Washington, and he said something about maxwellian distribution and the Todd Rider paper. Would it take millions to rebuild WB-6? Could someone like you or Richard Hull do it?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/29/2007 12:41 PM
Three of the EMC2 lab people were hired by SpaceDev.   There is no money for salaries at the moment, but my understanding is that Dr. Krall is still interested, and Benson has expressed a strong interest.  I wouldn't want to give the impression that "the fix is in", in case anyone else is interested, but there does seem to be at least that much interest.

Gaseous electronics is alive, and has an annual conference.  I attended one a few years back.  That includes things like vacuum tubes, thyratrons, plasma displays, and gas discharge lighting.  A MaGrid style Polywell is essentially a vacuum tube diode with a magnetic field around the anode, and so would probably qualify as a magnetron.  The machine is an Elmore Tuck Watson machine (electron accelerator) with a magnetically insulated anode grid.  With high electron densities and energies, one property of the magnetic field is that it displays a trapping phenomenon called a Wiffle-Ball which increases electron densities inside the grid by a factor of some thousands.  Cusp losses from this trap (one of Rider's objections) are not really a problem as the MaGrid simply recirculates them.  The electrons only want to get to the anode.  Rider probably was only familiar with an earlier form of the machine called HEPS, which did not allow recirculation of corner cusp losses.  High electron lifetime at high kinetic energy is what makes the deep potential well that drives the ion trapping, and this must be efficient to make it work.  The loss rate of electrons across the field to the MaGrid needs to be low ... that's MaGrid Transport. WB-6 finally got the shape of the MaGrid right to greatly reduce those losses.

You can build a small machine, but the scaling says you need larger to make net power.  But higher fields in a small machine would go in the right direction.

One of Richard Hull's friends, Ed Sines, lives about 3 miles from me and knows how to make high temperature superconducting magnets.  If the group at fusor.net could pool their talents, I think they could at least build little machines, especially on the scale of WB-2 or WB-3.  For big net power machines, I doubt they could afford even the vacuum chamber without real funding.

An estimate of the standard deviation of a counted event is the square root of the count.  The square root of 1 is 1, so a count of 1 should be taken as 1 +/- 1 to a confidence interval of about 65%.  In other words, you need more counts to really call it a number.  But the timing of the count, as low as the background count on those counters is, suggests it really did respond to a burst of neutrons produced by a 5 kV drive voltage and probably about a 4 kV well depth, putting the ion kinetic energies no higher than 4 keV.  That's off the bottom of the charts for most D-D fusion crossection plots.  The reason anything could happen is that the machine naturally has a lot of head-on collisions due to the radial nature of the ion flow, and that turns out to be the equivalent of collisions at 4x the kinetic energy on those plots.

At one point in his paper, Rider seemed to make the assumption that the machine would maxwellianize because all plasmas maxwellianize.  That's how plasmas are usually taught.  But a properly designed IEC machine has a very non-maxwellian energy distribution, and ions reaching the center are nearly mono-energetic.  IEC machines are particle accelerators, not heat machines.  The only place where a properly-run machine maxwellianizes is close to the inner surface of the MaGrid, where the ions slow down and turn around for another pass.  At that point, the density is high and they actually do maxwellianize ... and in the process equalize out any kinetic energy imbalances they developed due to collisions at higher energies.  Rider raised the objection that the high energy non-fusion collisions would result in maxwellianization, and the machine itself responded by using maxwellianization to fix the problem!  

The whole key is finding a density low enough to allow decent mean free paths for the ions when transitioning most of the radius of the machine, but still high enough that fusion is likely in the high-density central focus region.  Done right, you find this sweet spot, which is not unlike finding the right fuel/air ratio to make an internal combustion engine run.





Title: Re: Fusion with space related aspects thread
Post by: mong' on 01/29/2007 09:19 PM
going back to space related questions, what would be the typical specific power of, say, a multi-megawatt reactor ? are we talking Watts/kg ? KiloWatts/kg ?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/30/2007 12:51 AM
Let's see if we can extract what you want from "Inertial-Electrostatic-Fusion Propulsion Spectrum:  Air-Breathing to Interstellar Flight,"  Bussard and Jameson, JPP v11 No 1, pps 365-372.  I'll limit this to the "QED" craft utilizing relativistic electron beam heating of reaction mass, aimed at Mars flight. Figure 7 compares thrust to mass at various power levels and Isp, for the whole engine system.  If you want the mass of the p-B11 reactor alone, I don't have that in this article, but judging by size, probably less than half the mass of the system.  For a couple of these, that would put it on the order of a megawatt per kg.  Hey, I'm just reading the graphs here.  This is a direct conversion reactor with very little waste heat.

With this system, one has a choice of how much reaction mass to use with a given amount of energy, thus a range of Isp is possible.  My experience is Dr. Bussard is fond of fast rockets, and may tend to run a bit rich on the reaction mass, so higher Isp may be practical.  For landers or lunar missions, he tends to go toward an Isp of 1500.  For longer distances, he shows as high as Isp = 5500.  He also has another class of diluted fusion product engines that hit far higher Isp (he shows 70,000 sec but I think half a million may be possible) at low thrust.  I'm not sure if the figures below are his CSR or ARC versions, which differ in the cooling mechanism and size of radiators.

Tagging the four corners of this envelope, with apologies in advance for the the columns probably not lining up, and for the fact I'm reading log-log graphs on a Monday:

Isp      Megawatts       Newtons      Total System Mass kg
1500     1000                1.2e5             2e3
1500     6000                7e5                1.6e4
5500     1000                3.2e4             1.8e3
5500     6000                2e5                1.3e4
Title: Re: Fusion with space related aspects thread
Post by: mong' on 01/30/2007 10:36 AM
5500 sec. at 20 tons of thrust, that puts it above gas core nuclear thermal.
with that we can begin large scale settlement of mars, setup scientific bases on the outer planets, maybe a small colony on titan. those engines can use common propellants so sustained use should not be a problem
Title: Re: Fusion with space related aspects thread
Post by: TyMoore on 01/30/2007 12:35 PM
It sounds good--let's build one!

Is there any idea what the neutron flux is going to be? I know that we are talking p-B11 fusion--so theoretically there are no neutrons--but it has been my observation that there is always some neutrons produced from side reactions, etc.

Also, a thrust to weight ratio of 1:1 seems incredible for a fusion device. This machine--if built--would make a very nice compact powerplant all by itself. Infact, if it is as small as the 'graphs' say it can be--and I'm a bit skeptical here--then such units ought to be capable of being used for municipal waste treatment by indirect electric arc or even direct plasma contact...

Hmmm.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/30/2007 02:09 PM
That's what I say ... let's build one.  The naysayers have their math, Bussard, Krall, Jameson, and Wray have their math, and we can do math until we're blue in the face, and the only thing that proves anything is to build the bloody thing and try it.  Or so says the guy who can't do the math at the level of these guys.  Mike Faraday was my kind of lab rat.

I ran into a figure of merit for various nuclear fuels somewhere yesterday.  From memory, I think p-B11 was something like 50x better than D-He3 from the standpoint of neutron emissions (D-He3 has D-D side reactions, half of which make a neutron).

Skepticism in fusion claims is warranted and healthy, as long as it doesn't make us unwilling to try the thing that finally works.
Title: Re: Fusion with space related aspects thread
Post by: mong' on 01/30/2007 05:03 PM
especially when you have an experiment that works, albeit a smaller one

EDIT: I just looked up VASIMR projected performance, it would seem that with the heavy 10 GWe reactor Dr. Bussard is proposing it could reach 5 tons of thrust at 30,000 sec. ISP using hydrogen(!)
that means settlements on the outer planets and definately a large colony on titan
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/30/2007 10:05 PM
Oh, yes.  One of his papers specifically mentioned a rocket made for colonizing Titan.

But Mars is Bussard's first love.  He'd like a place "a little south of Syrtis Major."
Title: Re: Fusion with space related aspects thread
Post by: mong' on 01/30/2007 10:07 PM
who can blame him ? :)
Title: Re: Fusion with space related aspects thread
Post by: coach on 01/31/2007 02:29 AM
I just watched the video and yes, let's build one.  I just read an article on ScienceDaily about a professor at the University of Calgary who recently published an article on procrastination.  It was published ten years late.  No kidding.  If yeahoos like this can be paid for "scientific" results, can somebody please angel invest this fusion project?  If I had 5 million to spare, we could settle this debate once and for all.


Coach
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 01/31/2007 07:44 AM
I wish more people would take the time to sit through the entire 90 minutes of the Google video. In the last thirty minutes, Bussard explains that acid rain and air pollution will be eliminated worldwide when his fusion cube is retro-fitted to all existing powerplants. He goes on to say that neutron sources powered by fusion can transmute all existing nuclear waste to benign elements in fourty to ninety years. He has plans to replace oil with ethanol from sugarcane at 35 cents a gallon worldwide. He suggests that third world countries can get themselves out of debt by selling sugarcane to the developed world to replace oil. He claims that OPEC won't mind because they can turn their deserts in farmland with fresh water from fusion desalination plants and feed themselves. He sees his "fusion age" as ending oil wars and world economic instability. Oh yes, and by the way, he can get you to mars in three weeks with his fusion rocket!

I feel like one of the disciples of Bussard. I just want to sell all my belongings, and go study gaseous electronics, and make it happen!
Title: Re: Fusion with space related aspects thread
Post by: josh_simonson on 01/31/2007 08:10 PM
Not to mention that no country will again be able to claim that thier uranium enrichment shenanigans are for 'peaceful electricity generation purposes'.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 01/31/2007 09:29 PM
I've been working on a sequel to "The World's Simplest Fusion Reactor".  It is too long and I've been stripping stuff out of it.  The biggest part pulled out was a speil about all the things that p-B11 reactors could presumably fix.  My rationale is that the readers are going to recognize this quite quickly on their own.

Thank you guys for confirming that.
Title: Re: Fusion with space related aspects thread
Post by: jak42 on 02/01/2007 03:40 AM
Tom,

I am not enough of a physicst to judge whether or not this thing will work technically, but I think the problem is that it won't work financially, $2e8 is just too much money for someone to put up for a risky venture like this (yes, even Serge Brin and Larry Page, they have their financial guys to take care of their portfolio and this kind of thing is way off the curve w.r.t. risk v.s. amount invested for such financial guys).

It is not entirely clear to me why it would take that much. Does a new factory need to get built to make these things, or maybe there is some expensive material, platinum or the high temp superconductor material? Does Dr. Bussard have a business plan?

The typical Series A early stage startup funding in Silicon Valley is somewhere around $5e6 these days if the founders have a track record, and that is expected to last a year or so. The VCs are usually looking for a business track record together with a technical track record. Clearly Dr. Bussard has the technical track record, Jim Benson was mentioned and he might be a candidate for the business track record (though I think most VC types would not see it that way, despite what the alt.space community thinks of SpaceDev), but I believe he's busy with other projects. In some cases, with a really good prototype story, companies are able to raise something like $4e7 to $6e7 on their Series B round. Many of the new clean tech/solar energy companies, like Mirasole, are seeing that kind of funding. The money is really there, the VCs complain that they just aren't seeing any good deals.

If there is some way the proposal can be restructured to fit into the comfort range of your typical VC, I think you might have a much bigger chance of getting funding. That and line up a superstar business type, with at least one $8e8 to $1e9 valuation exit under their belt (aquisition or IPO, doesn't make a difference) to help round up the investors and lead the venture.
Title: Re: Fusion with space related aspects thread
Post by: braddock on 02/01/2007 08:47 AM
I think jak42 has some good points.  Dr. Bussard's google presentation wouldn't really be palatable for investors, especially the cost slide from 1994 with penciled in updated round numbers!  It makes one question his judgement...an impression you do not want to make when trying to convince someone that you achieved fusion in the last split millisecond of your prior, canceled funding just as the machine blew up.

I hope he has some good business types helping with the pitch.  At a minimum, any technology incubator would be thrilled to have him walk in the door, polish him up, and connect him.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/01/2007 01:05 PM
Valid points, generally speaking.  Most venture capitalists would want breakeven already done, with a good idea of how soon they can expect a return on their investments.  For the breakeven attempt, it is a big extrapolation from the existing test results, with no guarantee of a payoff.  Consider, though, that the same thing applies to most space ventures.  Communications and earth-resources satellites make money, but what about deep space exploration?  Not too many venture capitalists doing that, yet, I think.  There will be.

It is ONLY $2e8.  That's enough to buy a really nice yacht.  That's what NASA calls a "cheap" space mission.  There are hotels in Vegas that probably spent that on their lobbies.  Ford lost that much a week last year.

It is not something every investor would want to risk.  The article I'm presently working on asks "Do I expect somebody to read this article and just pull out their checkbook?  That would be nice, but I don’t think this should be undertaken by an idiot."  This is a venture that should not be undertaken without fully understanding the risk and payoffs.

There actually is a much smaller investment to make first, a few million to build WB-7 and WB-8.  These would be the same basic size as WB-6, one a truncated cube, the other a truncated dodecahedron.  The main intent is to figure out if the 12-magnet model works enough better than the 6-magnet model to be worth fiddling with on the big machine.  In the process, it should be possible to try for considerably extended run time.  That should cost a few million.
Title: Re: Fusion with space related aspects thread
Post by: jak42 on 02/02/2007 02:49 AM
Tom,

How long the VCs expect before payoff really depends on the business opportunity. You are right that most VCs look for a 3-5 year payoff, but there are some exceptions. One of the most notable right now is Linden Labs, the company that runs the virtual reality environment Second Life. The VCs have about $10 million in Linden at the moment but they are smart enough to know this is a longer term proposition and probably won't really pan out for another 3 to 5 years, and they started funding 2-3 years ago. But when it does, they expect it to be really big, that's the deciding factor in whether they're willing to stay in it for long enough.

Regarding your comments on WB-7 and WB-8, that's a good place to start as a proposal for the Series A funded prototype. Of course, the business plan needs to build from there, and must show profitability at some point. If I were you, I'd start by pitching it to NASA's new VC arm, Red Planet Capital. And I'd pitch it as a compact power source for moon/Mars without the dangers and potential public relations problem of having to launch a bunch of uranium. They might agree to take on the role of lead investor, and, even if they don't, I'm sure they'd be willing to give you some tips about how to refine the business plan and presentation.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/02/2007 04:09 AM
Jak42,

Thanks for the tip.  Neat name for a VC group!  I took the liberty of forwarding your suggestion to Dr. Bussard.

I heard a financial report on the news this morning about record oil profits.  I think it was Exxon.  Their earnings were nearly a hundred million dollars a day!

Maybe they'll bail Ford out so people can still buy Expeditions!
Title: Re: Fusion with space related aspects thread
Post by: publiusr on 02/02/2007 09:59 PM
A small black hole several AUs out might make for a useful platform . A bit of reaction mass fed into it micrograms or less at a time. The x-ray jet at the poles for high energy physics. The BH rotates one way--the surrounding sphere or torus (water filled) rotates the other for elecrical generation from fields perhaps...
Title: Re: Fusion with space related aspects thread
Post by: braddock on 02/03/2007 10:39 AM
Quote
Tom Ligon - 1/2/2007  9:05 AM

There actually is a much smaller investment to make first, a few million to build WB-7 and WB-8.  These would be the same basic size as WB-6, one a truncated cube, the other a truncated dodecahedron.  The main intent is to figure out if the 12-magnet model works enough better than the 6-magnet model to be worth fiddling with on the big machine.  In the process, it should be possible to try for considerably extended run time.  That should cost a few million.

This few million is definitely what you should look for.  Think of it in terms of EMC2's own valuation...if a VC gives EMC2 $200 mil, he will OWN EMC2...that won't be an investment so much as a purchase, with the founders crammed down to minimal ownership as the VC takes on all the risk and uncertainty.

A few million to get WB-7 and WB-8 to prove the effect is a different ballgame.  I should think you could get a VC to give EMC2 that easily, and it will only cost maybe 20% of the company.  Spend that over two years, prove you have achieved a fusion breakthrough beyond a resonable doubt, and suddenly you could be looking at a billion dollar valuation.  

NOW you bring in the $200 million, at a cost of only another 20% of the company.  The founders, including the Series A investor who upped the few million, all maintain a very meaningful stake in the company.  Or you simply sell the company outright and develop production systems on someone else's dime while getting paid for the investment in advance...

The closest analogy to EMC2 is a biotech startup with a potential miracle drug, and that is what a biotech would do at the stage when their miracle drug is proven - sell to a large company with the capability to handle the enormous task ahead.  As with a new drug, you are looking at a long road of government approval, public relations, safety evaluation, R&D, energy regulation lobbying, etc to get fusion to market.

Exit Strategy for founders and Series A: Prove fusion technology, and sell the technology and company to a large player for commercialization in three years for >100 times initial cash investment.  THAT is what any VC will want to see on your last slide.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/03/2007 03:19 PM
Interesting approach.

Keep in mind, I'm just a sideline cheerleader.  I have not worked on the project since 2001, so I'm not part of any official team putting together proposals, nor am I part of any of the strategy for finding a sponsor.  Its just that we were under constraints by the former sponsor to keep quiet.  Now that Dr. Bussard has been able to come forward and present results, I can finally talk about it.  It just feels really good to know he finally figured out what was wrong with the early devices ... a simple change in shape and spacing, and now it looks like the results match the theory.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 02/03/2007 07:00 PM
Tom do you think it might be a good idea if you and Dr Bussard went on the Space Show? To talk about the system and how it can be used in space?

http://www.thespaceshow.com/
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/03/2007 07:47 PM
Its not out of the question.  I'm being interviewed tonight by a British physics journal on the subject of the amateur fusion effort.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 02/03/2007 08:06 PM
If you ask me this sounds like one of the most important projects of the early 21st centruy so I do hope people will take this seriously.

There seems to be quite a bit of call for google to fund this. NASA and google are already working together on visualization, and this as an effort by both to fund and use. This will surely be a huge PR boom!

And you can have the US gov energy department fund a bit citing national security and well being makes it at super high priority.

If the oil companies were smart they'd buy up the rest of what they can get so that they can use it to convert the oil industry to a hydrogen/oxygen/energy/trash disposal/alt fuel industry that can be worth MUCH more than using oil.

They have extreme profits with oil but I can see an all American system greatly enhancing those profits and getting the political climate off their backs.

Good luck!
Title: Re: Fusion with space related aspects thread
Post by: publiusr on 02/10/2007 06:29 PM
The systems that you advocate will probably be done with pilot plants paid for by Gov't money taxed from oil companies. The last Congress gave subsidies to the oil companies to keep doing what they were doing. You have to force better behavior from business by regulation.

Both sides of the political spectrum are guilty of harming engineering efforts. Environmental zealots and NIMY types won't stant for plants built in their state (some even hate windfarms that will "ruin" the view of the ocean from the Hamptons or whatever). free traders want business over seas.

The effect is that the US has lost its appreciation of heavy industry--not helped by nano-tech gurus who think pixie dust will take over for same.
Title: Re: Fusion with space related aspects thread
Post by: coach on 02/16/2007 03:00 AM
I've been absolutely intrigued and read as much about this fusion breakthrough as I can understand.  Rarely do we get to witness the birth of a technology that has the potential to be so revolutionary.  Cars, computers rockets and airplanes come to mind immediately but this is so big it's hard to understand all of it's consequences, good or bad.  Can somebody out there give me some details?  How does a fusion rocket affect access to space?  From the ISP's and T/W ratios kicked around it seems incredible.  Will this technology be able to make VTOL craft that fly to the moon and back without refueling?  Am I just scratching the surface?

Coach
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 02/16/2007 04:23 PM
One of the possibilities that Bussard specifcally mentioned was a horizontal take off spaceplace that was single stage to low earth orbit with this clean fusion technology. You call it clean because his proton-boron fuel combination produces no neutrons.

A decade ago Dr. Anthony Zuppero did a study about capturing water bearing comets with a nuclear fission steam rocket. The nice thing about this idea is that water is then a "fuel mass" as well as a human consumable, and radiation barrier material. He has a website called Neofuel. The only problem was, back then, going out to get the comets was uneconomical by a factor of twenty, even with a fission steam rocket. Well now that Elon Musk and his Falcon 9 have a good shot at dropping the cost to LEO by a factor of ten, that should mean going to get comets is only off by a factor of two now. Since most comets are thought to be roughly: one third water, one third tar, and one third dirt, bringing comets to L5 has been the holy grail for would be space colonists since the days of O'Neill. The tar may turn out to be more valuable than the water, as it can be used to make advanced plastics like Vectran, and M5, as well as carbon nanotubes. Couple this with Bussard's claim that all the science is done for clean fusion and now you have a clean fusion steam rocket that moves mass around the solar system. I swear the more I think about it, the more I think that we are closer than ever to fufilling that old L5 Society goal of having it's last meeting on the first space colony at L5!
Title: Re: Fusion with space related aspects thread
Post by: hyper_snyper on 02/16/2007 07:25 PM
Quote
Tony Rusi - 16/2/2007  12:23 PM

One of the possibilities that Bussard specifcally mentioned was a horizontal take off spaceplace that was single stage to low earth orbit with this clean fusion technology. You call it clean because his proton-boron fuel combination produces no neutrons.

...

How is a horizontal takeoff spaceplane possible with fusion?
Title: Re: Fusion with space related aspects thread
Post by: GraphGuy on 02/16/2007 08:15 PM
One presumes that they would use a NERVA style engine where the LOX is heated by fusion and ejected.  You could probably get high thrust and really good ISP- enough so that you have > 1g acceleration.

More likely you would use this for something like the Ares V but with a single stage to orbit and 2-3x the capacity straight to mars (due to the much higher ISP).

More likely still, this thing would just stay on the ground and make power (assuming that the fundamental physics work as advertised and all the kinks work out).  If this was to power something, a supercarrier would be a good option as there are no weight constraints.  If you used this to power a spacechip it would probably be from LEO to Mars.

I hope he gets his funding, his approach is rather unique.
Title: Re: Fusion with space related aspects thread
Post by: GraphGuy on 02/16/2007 08:27 PM
Quote
PurduesUSAFguy - 19/11/2006  3:59 PM

I guess the main question in my mind is how do you convert the reaction in an IE containment fusion device into useable power? It seems like engineering a pressurized water loop through such a device would be difficult and I don't think you could use MHD coupling with Boron-Hydrogen fusion, although I don't really know...

It's an interesting concept, and I hope it works, but so many have worked so long on fusion that I tend to be very skeptical of anyone who has 'figured it out' outside of the established plasma physics community.

That being said I do think that the answer to commercially viable fusion is something 'out of the box' and that ITER isn't the road to fusion power. I think we need to focus more on novel devices like Princeton’s near spherical tokomak and basic plasma physics.

This probably was responded to earlier, just thought I would kick the dead horse possibly once again.  Apologies if this is redundant.

IE fusion uses electrical fields to cause fusion.  The energy byproducts of fusion are neutrons, EM radiation (heat/gamma) and the fused atoms.  neutrons and EM radiation won't be influenced by the electrostaic field (having no chare) so this energy would leave the machine where it could be captured.  You could wrap the whole thing in a PWR system and replace the fission part of a current reactor.  Obviously you would have to cool the magnetic coils themselves but doing so is much easier than the wall of molten Lithium neutron trap that ITER is planning on using.

You are right that ITER is not the road to commerical fusion, at least not any kind of affordable fusion.

Bussard is not outside the established physics community.  He is one of the icons of the established community.  Ever hear of the Bussard Ramjet?  Bussard worked to establish the DOE tokomak programs back in the 70s as a way to guarantee funding for fusion research and he is generally rather dismissive of ITER as being the burecracy that won't die that he helped to create.

Again I really hope that someone finances more research in this area.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/16/2007 09:08 PM
Something like this?

http://en.wikipedia.org/wiki/Energy_amplifier

Somebody beat you to it in a related thread.

The preferred embodiment of the device burns p-B11.  Virtually all the energy from this comes off as energetic alphas, which, in principle, allows direct conversion to high voltage DC at high efficiency.  The reaction is aneutronic.  For space propulsion, this would be great as it reduces power conversion mass and radiatior requirements.

If he has to resort to DD, I believe Dr. Bussard would likely opt for DT instead, and use the lithium blanket to breed more T, just like ITER intends.  DD only produces a neutron half the time, the rest of the time makes a proton, which would hit the chamber walls and make heat.  But the option of using the device as a neutron source to drive a fission reaction is clearly a possibility.

Back in 1995, I learned from my old company that somebody named Bussard needed some vacuum leak testing done.  So when I quit to set up my own consulting service, I dropped by the address and slipped my propaganda under the door.  When I got a call from "R. W. Bussard" a couple of weeks later, I asked "I gotta know, is this THE R. W. Bussard, as in interstellar ramjets?"

He replied, "I guess I'll never live that down."

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 02/17/2007 01:15 AM
GraphGuy,

Actually I think the Nerva rockets heated hydrogen, but I guess they could heat oxygen too, but it might be too corrosive to deal with in the heat exchanger with a liquid lithium loop going into the fusion cube to pick up the heat. One of the guys at Bigelow, James Hopkins, was claiming that you get better heat transfer to the hydrogen by spiking it with 10% methane. I looked into this when I was working at Bigelow Aerospace, where I was doing trade studies for the Lunar Cruiser concept. It was an earth-moon cycler for tourists who want to spend a week on a lunar flyby. If you look at the tank volume though, the Nerva hydrogen tanks would be nearly as big as the conventional chemical rocket tanks for a cryogenic oxygen and hydrogen set-up. Although you would have to refill them less often, because of the higher ISP for the NERVA thermal rocket, vs. a chemical rocket.

I really like the idea of a clean fusion thermal rocket with water propellant however. There is no possibility of any type of radioactive debris ever. This keeps the eco-kooks happy. The whole design is much simpler, since you don't have to deal with any cryogens that explode on contact with everyday materials like asphalt, which is still pretty common around most airports. Unless the water is superheated steam, there little likelyhood of explosion, and the liquid water propellant is much denser, so the tanks don't have to be that big. You can throw some MHD in the fusion cube to get out the electricity you need, but the rocket is a simple heat engine.
Title: Re: Fusion with space related aspects thread
Post by: publiusr on 02/18/2007 08:46 PM
What Stan Borowski wants is an oxygen afterburner. The LH2 is heated and mixed with LOX for thrust augmentation.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 02/21/2007 07:26 PM
Bussard says the smallest you can get breakeven with the proton-boron fuel is an eight foot cube. If that puts out 100 MW, and I only need 100 KW for my VTVL ultralight, then I only need a nine inch cube to power it! If we could just figure a way to get breakeven in a smaller package....;) di-lithium crystals???
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/21/2007 07:53 PM
I had dilithium power on my old Kaypro 286.  The tech pointed it out. TWO lithium batteries supporting the static ram and RTC.

While Dr. Bussard does not believe you can scale a MaGrid reactor down so far, that sort of powerplant would allow fuel synthesis.  He believes it would make it possible to make alcohol from CO2 and water, and it would certainly make hydrogen and oxygen by electrolysis.  He may be referring to the Fischer-Tropsch process in the link below.

http://www.greencarcongress.com/2006/03/a_proposal_for_.html

Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 02/21/2007 09:08 PM
If we can find a cheap way to get the C02 out of the atmosphere then this sounds like a perfect solution for use of IEF.

alcohol of course has many uses.


What if Bussard teamed up with someone with a real solution for removing C02 from the atmosphere to use IEF as the "power" of the process.

And I'm sure they can sell the may tons of alcohol to industry or use it as rocket fuel.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 02/21/2007 09:23 PM
Good idea, bad business model.  There's not much profit in it, unless governments fund it with taxes as an environmental cleanup process.  And CO2 drifts across national boundaries, so nobody will want to pay to clean up someone else's mess.

The GreenCarCongress proposal is to use it to clean up the stack gas of fossil fueled plants, and that's a whole different game.  Catch the CO2 at high concentration at the source.  One could tax CO2 emissions heavily, encouraging producers to scrub it.  If they can sell the byproduct, converting tax to profit, that's incentive.

The laugh is, that strategy probably would not last long.  If these reactors run that well, the fossil fuel plants will be shut down as fast as the replacements can be brought on line!  That's even better:  instead of using the carbon from fossil fuels twice (half the emissions), you don't use it at all.  You would end up using ag wastes as feedstock instead.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 02/21/2007 09:39 PM
Well I hope google will consider funding or somebody atleast.

This is why we need the prize model on more projects. The US energy dept ought to offer millions in prizes for people wanting to create such problem solving devices such as IEF.

Virgin is doing it and I fail to see how anyone can turn a blind eye to 25 mil for this.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 03/01/2007 04:55 PM
Jim Benson the billionaire controlling Bussard's fusion lab equipment will be interviewed LIVE! on David Livingston's internet Space Show on Sunday! Tune in and find out about our energy future and the first real breakthrough in space propulsion in fourty years! David takes questions from listeners on the phone or off of e-mail LIVE.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/01/2007 06:44 PM
Great news! :)
Title: Re: Fusion with space related aspects thread
Post by: coach on 03/01/2007 07:54 PM
Fantastic news!!!  I've tried to soak up everything concerning Bussard's fusor since I first heard of it but there hasn't been anything new for a while.  Thank God for message boards!!!   I'm sure Jim B. wants to talk about SpaceDev and Benson Space more than this fusion experiment but hopefully someone can squeeze a question in.

Coach
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/04/2007 09:09 PM
I just listened in, and some guy named Tony ;) called in and got Benson to talk about Bussard's ideas.  Benson said Bussard has a draft agreement of some sort in front of him right now ... I don't know what is going on exactly, but it sounds like maybe a business plan or proposal of some kind might be in the works, to give potential investors something to chew on.

If any of you who missed it would like to hear the interview, the podcasts are archived on the website listed above.  Benson touched on a number of topics here in the Advanced Concepts section.
Title: Re: Fusion with space related aspects thread
Post by: coach on 03/05/2007 02:30 PM
After listening to the program, I got the impression that there was a sense of urgency on Jim B.'s part to help make this happen.  The rest of the program was great, too.  Worthy of another thread even.  But I was suprised that Benson gave so much time to answer Tony's questions (close to 10 minutes worth).  He didn't dodge or minimize the importance of the question at all.  In fact, after listening to Benson and his overall vision I got the impression that nuclear fusion propulsion is the kind of breakthrough that he would be looking for to make his dreams of exploring and colonizing the solar system a reality.  He also made mention of the fact that if and when a deal could be worked out with Dr. Bussard it will be made quite public and transparent.

Thanks Tony

http://www.thespaceshow.com/detail.asp?q=680


Coach
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/05/2007 04:19 PM
This is the first time I've heard Benson's side of it, but Dr. Bussard has been telling me that Benson is eager for the chance to pursue this, and he's never misled me before, so I expected as much.

The rewards are admittedly a bit of a stretch for Benson's usual business plans, or for anyone.  But he evidently moves in the right circles to know how to make this sort of thing happen, if anyone does.
Title: Re: Fusion with space related aspects thread
Post by: kkattula on 03/07/2007 10:31 AM
Maybe the good people at the X Prize foundation will be interested, Larry Page of Google already knows about Bussard, obviously since they hosted that talk.

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/03/05/DDGFOOEF4C1.DTL

I'm not sure if they will directly fund projects or just set prizes. But a lot those people could afford to fund it outside of the Foundation, and they clearly are interested in advancing technology.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/07/2007 04:43 PM
One would hope.

The Mega Millions jackpot last night offered Fate a chance to Fund Fusion.  Alas, Fate turns out to also not be a risk-tolerant venture capitalist.  The lump sum payoff, before taxes, would have funded the DD machine and come pretty close on p-B11.

At least I did not have to fight with my wife over how to use the winnings.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 03/08/2007 07:21 PM
I got an interesting e-mail last night from Doc Bussard. Some of you may be interested in helping him.

Just a short note to clarify some of your comments in re our interests in fusion and its development. When we closed our Navy-supported EMC2 labs in Dec 2005, the Navy-owned equipment was to be sent for storage to USN/ChinaLake. However, Ms. Dolly Gray, our President, suggested that it might be useful to some other local company with DoD contracts, if it couild be transferred to such a company. Jim Benson's SpaceDev was local and had AF contracts for which the space chambers could be used, so - to avoid simply storing the eqpt - we arranged with Jim to transfer it to his company instead. And he found that our three lab people were good acquisitions for his company's work as well.

Thus, we managed to salvage almost a million dollars worth of government equipment for SpaceDev, in the hope that it could be used there. SpaceDev has not, to this date, found an internal use for it, and it is thus not reassembled and available for use. We had all hoped that DoD funds might be found to restart our own shut down work, which we had planned to conduct jointly with SpaceDev, but this proved not the case. If we succeed in finding funds to support our restart we will likely put a new lab in Albuquerque, NM, near to the LANL, SNLA and AFRL, and build test setups tailored to the needs of the two new machines WB-7,8, that we hope to build and test in the first phase of the development effort..

We have formed a new non-profit organization to accept tax-deductiblde donations for this work; it is EMC2 Fusion Development Corporation, under the 501C3 umbrella of the New Mexico Community Foundation (NMCF), at 343 E. Alameda, Santa Fe, NM 87501. Contributions can be sent to NMCF at that address, marked for EMC2Fusion, and this will help us get going again towards the end solution of the oil problem. In a week or so we will have a web site with more details. I will send you the web address when it is available. .

Cheers, RWBussard

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/08/2007 09:03 PM
LOL!  Tony, would you believe Gary C. Hudson (HMX Inc) saw where you posted that elsewhere, found my name here, and e-mailed me wondering how to contact RWB?  They're old friends, and it turns out he's worked with my company.

Very small world we live in.

I'll probably make a donation, but I've got a mad-money IRA (an old 401K that got ripped off so badly I never expected a cent back) that might make a nice vehicle for investing in the VC effort, if I'm not too small a fish.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 03/08/2007 11:41 PM
Gary Hudson is a cool guy. Now I am hoping that Dana Andrews and other real rocket people will be interested.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 03/09/2007 04:15 AM
This is an extremely important project that can define the very future of humanity.

If anyone has contact with Dr Bussard please thank him and his team for such amazing work. I guess him going NonProfit forfeits any chance of him earning a profit and thus he seems to be giving the technolgy to humanity.

Are we smart enough to accept it?

I know some here are republicans, democrats, libertarians, greens, Indies, etc... PLEASE when this website is up start to post about it everywhere you can!

I have an account at Democratic Underground that I use when talking with intelligent people there. I will make a huge topic in their Environment/Energy section when this chance presents itself.

Anyone that is a local at Free Republic PLEASE do the same as this is a serious issue that needs not to be viewed as a party favor of anyone.

It is disappointing that SpaceDev cant be "as" involved as one might have hoped. But with Nonprofit status Bussard has a MUCH better chance at donations and political support.

Contact your local city mayor/news about discussing it publicly in your town.
Contact your public representatives in state and federal levels.
Email your friends, political candidates, (some also have blogs/forums so please post there) Corporations and others who are in a position to be affected by this and of course the President.

I really feel that this technology is the only kind that can put an end to the regional wars in the middle east, and restore our self energy generation.
Title: Re: Fusion with space related aspects thread
Post by: kkattula on 03/09/2007 12:26 PM
This is great news, I was hoping for something like this to happen. I was starting to wonder if I should set up an NPO myself.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 03/11/2007 07:44 AM
Tom I see on the fusor forum that you feel that he is gearing up to "give away" the technology.

Assuming this means that he will completely publish every detail they have learned I am curious about how this will work.

Can you submit plans such as these fully documented to the ISO? (International Standards Org) To prevent another company getting sue happy to try to take credit for Bussard's work?



To be perfectly honest I am QUITE worried about this because he mentions that it will take quite a few YEARS with full funding to get this ready to fire up the prototype plant. I simply do not believe the world can wait any longer than 4-5 years for this before we go into mass panic over oil losses. I am hearing of Oil well shutdowns in the middle east that are resulting in less production in some areas. This could be a bad sign that oil there is quickly being used up that could end up costing HUGE amounts of damage and increases in fuel prices.

I feel the world cant wait for IEF. We seriously need 100MW plants running by 2013 at the most.
Title: Re: Fusion with space related aspects thread
Post by: kkattula on 03/11/2007 09:47 AM
I wouldn't be too worried about oil running out any time soon, it's just going to stay expensive, mainly due to increased demand from the developing nations, and turmoil in the middle east. At the current prices it's now economical to recover oil from older wells, and deeper off-shore wells.

It's also now economical to extract it from oil sands.  Canada alone has oil sands reserves equivalent to the worlds current crude oil reserves, and is producing huge amounts of oil from them. Venezuela has a similar amount too. The US has massive shale oil reserves in Colorado and Utah. Diesel can even be produced from coal for less than $45 a barrel.  All these sorces of 'unconventional oil' have been ignored in favour of 'easy oil' for years, but are now in play.

I'm eager for IEF to be developed too, the sooner it happens the better. But we do have decades, if needed, not just a few years.
Title: Re: Fusion with space related aspects thread
Post by: vda on 03/11/2007 12:03 PM
Quote
kkattula - 10/3/2007  12:47 PM
It's also now economical to extract it from oil sands.  Canada alone has oil sands reserves equivalent to the worlds current crude oil reserves, and is producing huge amounts of oil from them. Venezuela has a similar amount too. The US has massive shale oil reserves in Colorado and Utah. Diesel can even be produced from coal for less than $45 a barrel.  All these sorces of 'unconventional oil' have been ignored in favour of 'easy oil' for years, but are now in play.

How alcohol compares to this, economically? It has an advantage that it is made from plants, and thus

a) production can be ramped up to match demand - we have plenty of places on this planet with lots of sunny days.
b) production of alcohol is much less monopolistic. Probably hundreds of vendors worldwide instead of a dozen. Forget about OPEC.
c) prices will be predictable and stable.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/11/2007 01:40 PM
Zachstar,

I assure you, you could not possibly have a sense of urgency on this matter any stronger than Dr. Bussard does.

I once wrote a story (never accepted for publication) depicting the dream he had of personally traveling to Mars using this technology.  I found a manuscript the other day that I had given him for review.  Scrawled on the back in his handwriting, I found the comment, "If only we'd been at this point in 1978 instead of now!"  He circled "If only" and added the note "This is the classical 'if only'".

VDA,

Present means of production of alcohol by fermenting sugars are inefficient uses of sunlight.  Already, the use of grain for alcohol production is pushing up the price of cattle feed, and there is rising concern over the clearing of rain forest for the production of more sugar cane.  

New methods now coming out which permit using cellulose as a starting material are probably more practical.  But it is possible, with a source of clean non-fossil energy such as fusion, to synthesize alcohol from carbon dioxide (Fischer-Tropsch synthesis).  This could use any source of carbon, from atmospheric carbon dioxide (probably impractical due to the dilute source) to almost any agricultural waste product.  I think, as a result, biofuels and fusion are probably a good match ... together they may solve our problems.  Fusion is likely forever too bulky to power personal transportation, but biofuels probably cannot, by themselves, fully satisfy our appetite for energy.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/11/2007 02:02 PM
Zachstar,

There's give away and there's give away.  Careful what you read into what I've said.  I don't think, at this point, Dr. Bussard is after funding in order to achieve any financial gain for himself.  That was part of the earlier dream, with the goal being to ... not making this up, he was dead serious about it ... use the profits to fund a Mars colony.  The story I mention above was a fictionalization of that dream.  And if there is anyone on Earth who could have dreamed up a practical way to do this, it is R. W. Bussard.  His papers from the 1990's all center around this goal.

I think, now, he is willing to turn the program over to somebody who can make it happen, which has an important distinction from just giving it away.  The distinction is, whoever develops this is most likely going to want to own it.  One thing you can be fairly certain of, is Dr. Bussard will not want to do anything to kill the development of the technology by killing the prospective profits for anyone with the courage to take this on.  He has applied for a set of patents recently, to protect the key ideas (one reason he can talk so freely now).   These patents will almost certainly wind up under the control of whoever agrees to develop the technology.  And he will also most certainly want to know that the new backer is firmly committed to making it happen.  This is not going to be owned by the guys building ITER, who would probably shred the thing and have the waste recycled to pasteboard.

The NPO presently set up seems aimed at tiding the project over until venture capital or an angel can take it over, perhaps getting out the detailed scientific paper we all hope is coming, and getting at least a start on, or even completing, the WB7/WB8 project.   Could the NPO fund the whole demo reactor program?  A dollar from every US citizen would more than do this, but I think it is faster and surer if a well-heeled entrepreneur with a good business plan and ability to raise funds and make things happen takes the reins.
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 03/11/2007 05:56 PM
The only problem I see with this is that he who controls this energy source controls the world.

I can see a big oil company shadowy funding some dude claiming he will fully fund this and then they will completely own this power source. This is a TERRIBLE idea that can lead to this company owning extremely large parts of earth economy.

I think that it is imperative that he foucuses on the political aspect of this technology by submitting it to a standards organization and fully exposing its workings before something really bad happens.

Why has the doc not thought of this situation? I can understand his company EMC2 getting rich like no other..

But the doc is a different man than a whole lot of people and wanted the profits from such a wonderful project going into a mars colony as you said.

Many others in the energy production industry have little care and just are in for the money. And thus more windfall profits from still high energy prices.

I surely hope he will decide to publicise the details
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/11/2007 07:38 PM
I'm sure he will publish more, if his health holds up.

At present, I see enough information has been published for someone to just build the darned thing.  The missing information is a detailed understanding of the model upon which the EIXL computer program is based.  You could build it, you just would not know quite why it worked without tedious reconstruction of the math from the descriptions already released.  And, without crunching the numbers using that code, you might not believe the thing you were building would work.

The patents are the primary protection against ripoff.

As for whom to trust, patents offer protection only for a limited time.  It is certaily possible someone with dark motives might try to acquire this, but I trust that people like Jim Benson will be around to sniff out the rats.  This genie is out of the bottle now.  If it can work, it eventually will, and the only thing the rats could do is delay it.

Which, as you say, would be a tragedy.  We need this, or something very much like it.

As the original dream was in a story Bussard approved for publication (which, alas, Stan Schmidt did not), I can at least reveal the fictitious business plan.   The character Q. V. Harris (easy code to break here) figured that the plan would be to license the design to be built worldwide, in exchange for a few percent of the power revenue.  This model would allow the oil companies and other major industries to buy a stake in the power production business by building or operating powerplants, but not exclusively.  Keeping the royalties reasonable makes everybody as happy as is possible in any marketplace.  And a couple of percent of the worldwide power revenues would certainly meet MY needs.

"If Only ..."
Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 03/12/2007 01:12 AM
Yes only a percentage and you can build the spaceport to launch colony ships powered by cluster ion drive.

Can you build them big enough and in enough quantities to handle 100MW? Gonna also have to buy a few propellant sources ;)

--------------------------------------------------------------------------

I can understand my lack of biz education. But is it possible for this Spacedev/EMC2 type deal to "own the technology" but promise a royalty free period for any major companies willing to fork over 20 or so million each to encourage development.

For a big oil company this is a great chance at PR. Take ExxonMobil and their TV campaign touting biofuels... Now if they sunk 100 mill into EMC2/SpaceDEV they can claim to be at the forefront of the real breakthrough in clean energy. Meaning that a whole lot of political pressure will be lifted from them and they will have this period of what? 10 or so reactors for no royalty cost?

I do hope that SpaceDEV gets to keep the idea and it not be "sold off" I know they can smell rats but rats are very good and the amount of patent buyoffs and shelving is extreme. For instance it seems that a very efficient engine/vehicle design that could take 4 persons and light cargo at up to 100MPH over 10 years ago got bought and shelved because had the design gotten out then foreign manufacturers would have flooded the market with super efficient cars.

As long as EMC2/SpaceDev effective "own" this technology then the oil/energy companies will be forced to adapt their infranstucture.

However my hope is that instead of waiting for these companies to realize this I want to US GOV to step in. Even with red tape 150 mil development contract or so  for a full scale reactor setup to power an example Military base or Gov area. If this single contract is clean enough perhaps it could branch through the Energy department to get contracts from major power companies to outfit their plants with IEF.

Just alot of brain to post type stuff but I need to get in this thinking mood before I take on the political and public aspect of this to try to gain support. There are quite a number of people who will not understand IEF and it's benefits.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/12/2007 02:02 AM
100 MW?  That's the little toy for the demo.  Let's see ... AIAA 97-3071, System Technical and Economic Features of QED-Engine-Driven Space Transportation.  My autographed copy.  For Mars, he gave a couple of options.  One was 6000 MW, with an Isp of 5500 sec.  500 ton machine, the thrusters heat reaction mass with a relativistic electron beam.  Hydrogen works best but with some tweaks a similar system can run on water (adjusting for some limit on regenerative cooling requirements).  He prefers water as it should be available on Mars.  He worked out payloads, etc, figured you could get to Mars for $232.60/kg.  Which is how much less than present launch costs to LEO?

The whole paper describes p-B11 ships from SSTO to Luna, Mars, Titan and the Oort cloud, each specialized for the mission but all using similar reactors.  Cost per pound for the SSTO to LEO was such that, applied to a 200 lb passenger, a ticket to LEO would cost less than a flight to Europe on the Concord, so we can afford to lift reaction mass for the Mars ship, provided you have confidence of finding water on Mars to get back.

Anyway, in the story, Q. V. Harris was able to affort a fleet of 6 Mars ships out of his own fusion-funded pocket, whereas Bussard thinks 18 would probably be more appropriate.  The sheer tonnage and number of people he figured to move for the Mars colony in this paper is mind-blowing.  But he was also going for very rapid trips, around 6 weeks, with about 20% payload mass fraction.  I recalculated what would happen if Q. V. piled extra cargo on the first flight of 6 ships so they took twice as long to get there, and it worked out around 5x the normal payload or some obscene number like that.

Its all wild speculation, unless we get those reactors going.  But if that happens, everything about space changes.  Dramatically.



Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/13/2007 12:00 AM
Over the weekend, someone from ISDC asked Dr. Bussard if he could repeat his Google talk for that conference, May 25-28.  I notice both Benson and Hudson are scheduled as speakers.

http://isdc.nss.org/2007/speakers.html

Dr. Bussard says he still does not feel up to attending, and has asked me if I can go in his stead.  So far, the one person I've heard from at NSS seems to have a kind of "Tom who?" attitude.  But, if they decide they want me, I'll do it.  I already have a fair amount of material prepared.  There's an abstract deadline this Friday, but I don't seem able to submit anything ... either it is down, or I need to log on as an accepted speaker to do it.

Anybody else from here attending?

Title: Re: Fusion with space related aspects thread
Post by: Zachstar on 03/13/2007 04:47 AM
You need to call them Tom and also send emails. Not much time to do that tho.


Good luck!
Title: Re: Fusion with space related aspects thread
Post by: lambda0 on 03/13/2007 05:55 AM
Quote
Tom Ligon - 11/3/2007  10:02 PM
...
100 MW?  That's the little toy for the demo.  Let's see ... AIAA 97-3071, System Technical and Economic Features of QED-Engine-Driven Space Transportation.  My autographed copy.  For Mars, he gave a couple of options.  One was 6000 MW, with an Isp of 5500 sec.  500 ton machine, the thrusters heat reaction mass with a relativistic electron beam.  Hydrogen works best but with some tweaks a similar system can run on water (adjusting for some limit on regenerative cooling requirements).  He prefers water as it should be available on Mars.
...

Hello
Is there a downloadable version somewhere, in pdf format for example ?

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/13/2007 01:10 PM
I can't find the original paper posted anywhere.  Lots of references to my original _Analog_ article, (which has it in the references), best version of which is here:

http://fusor.net/newbie/files/Ligon-QED-IE.pdf

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/13/2007 09:54 PM
I finally managed to get an abstract posted.  They must be running the site on a Radio Shack Model III.  SLOW!

Dr. Bussard has already e-mailed them encouraging them to accept me, and Gary Hudson just offered to do the same.
Title: Re: Fusion with space related aspects thread
Post by: Bruce H on 03/14/2007 12:10 AM
Quote
Tom Ligon - 13/3/2007  9:10 AM

I can't find the original paper posted anywhere.  Lots of references to my original _Analog_ article, (which has it in the references), best version of which is here:

http://fusor.net/newbie/files/Ligon-QED-IE.pdf


Interesting. Thank you.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/14/2007 02:13 PM
As a writer, I tend to be sensitive to copyright issues, otherwise I might scan my copy of AIAA 97-3071 and post it.  And since the cover is autographed to me, it would be obvious who provided the copy!

Down at the bottom of the cover page, it says "For permission to copy or republish, contact the American Institute of Aeronautics and Astronautics, 1801 Alexander Bell Drive, Suite 500, Reston, VA  22091."  I suppose they'll want money for reprints.

I think web publication is the way to go for this sort of paper, but if AIAA is depending on money from publications for their bread and butter ....
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/16/2007 08:45 PM
Dr. Bussard just contacted me.  He did just give me permission to utilize anything in the reports I have been talking about for my upcoming talk, including figures.  I'm sure he would be eager to have anyone interested look at them.  Contact me by e-mail and I'll see if there is anything I can do to somehow get you connected with copies.  Notice how cleverly I phrase that.

Also, his NPO website is up (doesn't say much, but it gives contact info and "credit cards and PayPal accepted"!  The main focus of the NPO right now is to get some of the papers out that he was not allowed to publish due to restrictions imposed on the folks prevously funding the work.

www.EMC2Fusion.org
Title: Re: Fusion with space related aspects thread
Post by: mong' on 03/16/2007 09:24 PM
so you'll be at ISDC ? that's real cool, I think you're going to make quite an impression there, good luck
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/16/2007 09:49 PM
They have not notified me that I am accepted as a speaker yet, but I have high hopes.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/18/2007 02:41 PM
Fusor.net just posted the following link to a story in Defense News on the project.

http://www.defensenews.com/story.php?F=2584496&C=america
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/19/2007 12:08 PM
I recently took notice of this thread and read the background info over the weekend.

Wow!!!

This changes everything.

If Dr. Bussard is correct, we can really expand the reach and survivability of the human race.

Given this technology what would be costs and time frames for sending robots to other stars?

Obviously, it would be faster and cheaper to send the first probes to do a fast flythrough, but eventually we will be able to take a longer look.
Title: Re: Fusion with space related aspects thread
Post by: palebluedot on 03/19/2007 02:04 PM
"This direct conversion process is extraordinarily efficient. About 95 percent of the fission energy is turned into electricity, Gay said."

So.. suppose they get the pB11 reaction going, and it gives more energy than it takes to create.. is that conversion process more than just a theoretical possibility? Could it actually work? 95% efficiency would be pretty amazing in it self. No more working fluids, turbines, waste heat..
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/19/2007 02:43 PM
95% is overly optimistic, in my opinion, but above 80% may be reasonable.

The reaction produces three highly energetic alpha particles per fusion, which carry most of the fusion energy.  The other 5% that is lost is mostly bremsstrahlung radiation.  

Collecting the kinetic energy of the alphas should be possible using the opposite of electrostatic acceleration.  Use their KE braking against an electric field to produce high voltage DC in a surrounding shell and series of grids.  The theoretical limit of efficiency of this would achieve the 95% Don Gay mentions.  The catch is, there will be some mechanical obstruction of the clear path for the alphas imposed by the MaGrid, so I think the net result will be significantly less than 95%.

But still, one heckuva bunch better than, say, a thermodynamic cycle based on steam and turbines.  And the requirements for heat radiators are greatly reduced, improving overall performance and economics.  A few posts up, there is a paper referenced that looks into all of this.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/19/2007 03:59 PM
And who's to say that you couldn't use part of the rest of the energy.  Let's say that for a 100Mw reactor
using the pB11 reaction, you get 80% direct conversion to electricity.  The other 20% goes into heat.

Well, the cooling system needed to get rid of that 20% could possibly run a thermal cycle to generate some electricity out of that waste heat.

This would only work if your not using superconducting magnets.  If you need superconducting magnets then your efficiency is lowered because you need to burn a lot of the direct conversion electricity to cool the magnets.

Question.  With "standard" tokomaks which use superconducting magnets, does the breakeven energy include the energy cost of cooling the magnets?
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 03/19/2007 04:09 PM
Quote
BarryKirk - 19/3/2007  10:59 AM

And who's to say that you couldn't use part of the rest of the energy.  Let's say that for a 100Mw reactor
using the pB11 reaction, you get 80% direct conversion to electricity.  The other 20% goes into heat.

And how do you get that 20MW of heat out of the vacuum chamber?  I suppose the shells will get hot and you can cool them from the outside.  But the coils are absorbing heat from electrical energy, losses from the Fusion products, and radiation.  It seems like a lot to ask to suck 20MW out of 6 2m donuts!  And the 6000MW rocket engine above?  That's over 1GW of heat to deal with.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/19/2007 04:13 PM
Actually, the superconducting magnets are supposed to be a great savings.  The resistive losses of copper magnets cost more power than the cooling system of superconducting magnets, at the scale envisioned.  And the resistive losses in copper would present a heat load that must be radiated.

Dr. Bussard's QED rocket designs referenced above all take into account the radiators and energy costs associated with superconducting magnets.

One of the benefits of p-B11 fuel is that a thin metal skin can stop the alphas.  This would load heat into the inner surface of the MaGrid and it would require cooling, but, as you say, it is not out of the question to recover some of this by conventional thermodynamic cycles.  This load also requires some radiators, just a lot less acreage than typical nuclear electric designs do.  The more heat can be drawn off of this outermost heat shield, the less reaches the underlying LN2 and liquid helium jackets, and the lower the cryo cooling load.

I worry that a neutron-producing fuel would ruin superconductors in relatively short order, as the neutrons would penetrate the magnets deeply.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/19/2007 04:24 PM
Lee Jay ...

Sure would keep the engineers busy!  But think about it, what a marvelous thing to get to the point where that's the big problem!

I think we would all be happy with 10 MW at 50% efficiency right now, if we could get it.



Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/19/2007 05:26 PM
Right now I'd be happy with 10MW at 50% efficiency.  Of course once that happens, people will be looking to improve that 10MW and to improve that 50% efficiency.

From the sounds of what I've read, it looks like technically it is a sure bet that net power can be generated from IEC fusion.

The questions are really how soon and that depends on the financing.

Any word on the state of the financing?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/19/2007 06:20 PM
I'm not in the loop on that (technically I am not actually associated with the project, I'm just cheering for it), but some of the right kind of people have been contacting me asking if I can put them in touch with Dr. Bussard.  I have no idea if any money has been changing hands.   I think he is at least going to get the NPO running fairly quickly.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/19/2007 09:30 PM
Here's a fun calculation ... I pulled out my aging Space Shuttle Operator's manual (old external tanks), which shows the shuttle carries 616,500 kg of LOX, which would burn with 77,062 kg of H2 if the reaction were stoichemetric (actually they run hydrogen rich).  Hydrogen burns with an energy release of 120E+6 joules per kg (corrected from error noted below), so burning the whole contents of the external tank should produce 9.25E+12 joules.  MECO is 518 seconds after liftoff, so that would give an average power production over the main engine burn approaching 1.79E+10 watts (there is a little left over).  

So evidently it is possible to work with rather extreme amounts of power in a fairly compact space.  Now let's see how far we can push it with a fusion source!


Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/20/2007 12:06 PM
With fusion, the energy density of the fuel both per kg and per m^3 is huge.  The question for building an earth to LEO fusion rocket is the power to weight ratio.  How fast can you extract that energy.  Actually the thrust to weight ratio is what it's all about.  If the fusion engine can't lift it's own weight off the ground.  It doesn't matter how much energy the fuel contains.

Now the thrust to weight ratio of chemical rockets is staggering.  With liquid engines like LOX/RP1 it can be over 100 to 1.  A fusion engine doesn't need anywhere near that thrust to weight ratio because the energy density of the fuel is so much higher.

If the thrust to weight ratio for a fusion rocket were say 10 to 1, but the fuel can provide 100 times the ISP, then your payload mass fraction will be orders of magnitude higher than for a chemical rocket.

Once your in orbit, everything changes.  Thrust to weight ratio almost becomes insignificant.  And it is there that a fusion rocket really becomes efficient.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 03/20/2007 12:21 PM
Quote
Tom Ligon - 19/3/2007  4:30 PM

Here's a fun calculation ... I pulled out my aging Space Shuttle Operator's manual (old external tanks), which shows the shuttle carries 616,500 kg of LOX, which would burn with 77,062 kg of H2 if the reaction were stoichemetric (actually they run hydrogen rich).  Hydrogen burns with an energy release of 120E+8 joules per kg,....

Unless I'm losing it (always a possibility) it's 1.2E8 J/kg or 120E6 J/kg (33.3 kWh/kg).

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/20/2007 01:41 PM
"Damn that decimal place!", said the engineer as the shuttle plummeted into the ocean a few miles east of the Cape.

Actually, it is a transcription error ... I entered 120E6 in the spreadsheet, it displayed 1.20E8, and I screwed up transcribing it.  But the rest of the numbers are correct.  I think.  Somebody kindly check before launch.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 03/20/2007 01:53 PM
I get 17.8GW which is what you got as well.  Of course, this is essentially external combustion so you don't have to extract the losses from a confined space like a *gasp* vacuum chamber.  In fact, is there much cooling going on at all in the SSME other than the nozzles?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/20/2007 02:04 PM
The two means of propulsion are apples and oranges, of course.  The main points are --

You sure would like to have the ability to make SSME kinds of power.

And since that has been demonstrated (who, in the 1930's, would have thought it possible?) maybe there is a way to do it using nuclear power, as well, or at least of getting up to the levels useful for interplanetary travel.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/20/2007 03:54 PM
A fusor designed rocket meant to go from ground to LEO would most likely have a totally different configuration, than one designed for interplanetary travel.

Perhaps, we would have a space station like the one in the movie 2001 where the earth to LEO rocket would transfer it's people and cargo to ships designed for pure interplantary operations.

You might also have a specialist type of vehicle without the ISP of a pure interplanetary rocket, but is capable of lunar landings.  Such a vehicle would be good enough for LEO to the lunar surface.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/20/2007 04:39 PM
Dr. Bussard envisions an air-breathing aerospace plane (rocket boost out of the last bit of atmosphere and to circularize) for the ground-to LEO flights.  As a rocket, I think he targeted 1200 sec Isp, but in the lower atmosphere it would have high thrust, much lower exhaust velocity.

LEO to Luna he expected to use essentially a lander.  A similar lander would go from Martian orbit to the surface of Mars (higher thrust, of course).

Interplanetary travel to Mars or thereabouts, intermediate Isp in the range of a few thousand seconds, using relativistic electron beams to heat reaction mass.  For longer missions, he favors "diluted fusion product", using the fusion reaction with some additional reaction mass to achieve very high Isp (>50,000 sec) at low thrust.

He did one paper speculating about "Single Stage To Anywhere" capability, but knows there is very little chance that would ever make good sense, for about the same reason the Taylor Aerocar never was an economic success.  The resulting craft would probably be worse at everything than the specialied craft.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/21/2007 03:34 AM
Well, durn! Thanks to people like Tony Rusi and Jstroud, evidently I'm going to be a guest on The Space Show. :cool: Dr. Livingston and I have not set a date yet, but he says he wants me.  I'll post when I know the date, but be aware that the schedule is pretty flexible.  The guest for tonight evidently had his rocket go missing today, so they switched guests at the last minute.

I'd still like to talk Dr. Bussard into it.  Evidently he's swamped right now with the new NPO, but these interviews are all done by phone, so it is not like having to go to a conference.

Title: Re: Fusion with space related aspects thread
Post by: jstrout on 03/21/2007 01:10 PM
Quote
Well, durn! Thanks to people like Tony Rusi and Jstroud, evidently I'm going to be a guest on The Space Show. :cool:
That's good news!  Can't wait to hear it.  Like many others, I'm hungry for anything I can get on this topic.

Quote
I'd still like to talk Dr. Bussard into it.  Evidently he's swamped right now with the new NPO, but these interviews are all done by phone, so it is not like having to go to a conference.
True.  Also, I just listened to Jim Benson's interview yesterday, and he said that he was trying to put something together — he mentioned Dr. Bussard and him working on an agreement that would enable them to go after some financing (I'm paraphrasing here, but I think that's the gist of it).  Do you know whether this NPO is what he was talking about?  Or is there something else in the works?

Finally, as for the NPO, I notice that http://www.emc2fusion.org/ doesn't currently have any way to contribute money directly — it says to send contributions to NMCF, but if you follow the link to NMCF, it doesn't mention EMC2 at all.  Looks like a bit of a disconnect there.  Who's doing the EMC2 web site, and do they need any help?

Thanks,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/21/2007 06:19 PM
The NPO must have been what Benson was discussing.  I don't think any other agreements are in place yet, so any of you with $200 M to spare, the deal is still up for grabs!

My guess is that having NMCF handle the donations get around a bunch of accounting rules NPOs must comply with in order to be sure they're legit.  Supposedly you can earmark the donations for EMC2Fusion.

The text of the announcement which I received gives these instructions, but you're right, the website does not, and it should.  I'll let him know.  And I'm sure he could use some help in the website department.

Here is the original e-mail "flyer" that had the link.

EMC2 Fusion Development Corporation

EMC2/FDC has been formed as a non-profit
charitable research organization

to develop Inertial Electric Fusion (IEF) power
as a clean energy source, based on the Polywell
polyhedral magnetic/electric approach of EMC2

Tax-deductible contributions to support a restart of the IEF work conducted by EMC2 from 1994-2006, can be sent via the New Mexico Community Foundation (NMCF). This organization provides the 501C3 tax-exempt umbrella for EMC2/FDC work

Contributions/donations can be mailed to
NMCF, 343 E. Alameda, Santa Fe, NM 87501

They should be marked EMC2Fusion for identification

NMCF will send you a letter of acknowledgement and thanks
and a record of receipt, for tax purposes. The funds will be transferred to EMC2/FDC to support the research

EMC2/FDC now has a web site, at www.EMC2Fusion.org. This gives more details of its work, and further information on how to reach NMCF directly and contribute by credit card and/or PayPal

It is planned to have an on-line IEF NewsLetter at periodic intervals, to report on progress, as the research effort gains momentum

Thanks for joining in this work to make clean energy available to all, at low cost, stop pollution, global warming, avoid nuclear fission and fossil fuels, make portable fuels to replace gasoline, provide fresh water, and end energy-driven conflicts
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 03/21/2007 07:42 PM
Quote
The NPO must have been what Benson was discussing.  I don't think any other agreements are in place yet, so any of you with $200 M to spare, the deal is still up for grabs!
Actually, Benson said that the first phase (two more subscale machines and a panel review) would only take $5M, and I agree, it's sensible to get that out of the way before worrying too much about the $200M.  I'd guess that if this step goes well, finding the $200M for the full demonstrator plant would not be too difficult.

So, anybody with an extra $5M can step up to the plate!  (Or, conceivably, that much could be raised with a handful of Hollywood celebrity fund-raisers.)

I still wonder if this is what he meant though.  Going back to the Space Show interview, Benson said at about 1:00:29, "I'm in the process of working with [Dr. Bussard], trying to come up with an arrangement whereby I could help him raise the money and fulfill his lifetime dream of clean safe fusion, but it's kind of touch and go right now, and I'm not sure how it's going to work out."  

Then at about 1:01:45, we have:

Benson: ...I'm doing everything I can to make sure that his work continues.

Livingstone: Have you ever thought of carving it out as a special investment opportunity with a partnership or some other structure just to fund this $5M program?

Benson: That's exactly what Dr. Bussard and I are discussing right now, and he has a draft agreement in front of him that would result in a structure that I believe would minimize the time and difficulty in raising the money and doing it step by step.  So, this is something that I'm working on as an aside, but it's something that I'm extremely focussed on and care a lot about.

Then later at 1:05:16:

Benson: If Dr. Bussard and I can reach an agreement, then it'll be highly publicized, and you won't have any trouble whatsoever finding out how you can get involved.  But in the meantime, he and I just need to concentrate on seeing if we can come up with a practical forward approach.

It doesn't seem to me that this NPO has been highly publicized — maybe because they're just not ready yet (the web site needs to be fleshed out for example).  But also, it sounds to me more like Benson had in mind something like a spin-off company rather than an NPO.  Makes me wonder if there's something else going on that hasn't been announced yet.

Quote
The text of the announcement which I received gives these instructions, but you're right, the website does not, and it should.  I'll let him know.  And I'm sure he could use some help in the website department.
Thanks for posting the announcement text.  And, the next time you talk to Dr. Bussard, please pass along my offer to help with the website.  I'm a professional software consultant, and I can certainly handle making a nice website.  I would happily do this pro bono, as my small way of supporting the fusion effort.  My email address is [email protected]

Thanks,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 03/21/2007 09:27 PM
For those of you interested in a more  open forum dedicated to power applications of IEC Fusion, technical talk, economics, finance R&D etc.  I have started a yahoo news group.

http://tech.groups.yahoo.com/group/IEC_Fusion/
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 03/21/2007 09:42 PM
Quote
For those of you interested in a more  open forum dedicated to power applications of IEC Fusion, technical talk, economics, finance R&D etc.  I have started a yahoo news group.
Ick — I hate Yahoo groups.  I have occasionally been forced to join one, though, so I suppose I could do it again.  In what way is your mailing list a "more open" forum than this one, or (say) the sci.physics.fusion newsgroup?

Thanks,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 03/22/2007 03:59 AM
It is more open in that yahoo is less intimidating than sci.physics or NASA. The reson for that is that I'm interested in raising money as well as discussing the physics.

BTW it has been a long time since I was on usenet. How does that work these days?

I did some looking into the usenet stuff - which gives me another reason for yahoo. Moderation.

Let me add another reason - on yahoo you can hide your e-mail address. usenet makes it public and opens you up to the spammers.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/22/2007 02:23 PM
Is there any links to that interview.  I would like to listen to it or watch it.  This is really exciting stuff.

Hopefully, kind of like the start of an avalanche.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/22/2007 05:40 PM
http://www.thespaceshow.com/

And scroll down to the March 4 podcast.  It works with several media players.  (If reading this more than a month from now, these shows are archived quite a while).
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 03/24/2007 02:13 PM
At the moment, my interview on "The Space Show" is scheduled for Tuesday May 8, at 7 PM Pacific.

Just to let you guys know that I'm about to step away from the computer for about 2 weeks.  I'm not being snooty ... I'm just off-line!  See ya! :bleh:
Title: Re: Fusion with space related aspects thread
Post by: publiusr on 03/30/2007 08:10 PM
All the Best...
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 03/30/2007 11:27 PM
Yes, good luck.  As for hearing about any more developements, the waiting is the hardest part.
Title: Re: Fusion with space related aspects thread
Post by: colbourne on 04/06/2007 04:35 AM
Are we setting our sights too high.
We are trying to achieve power output of more than the power input.
I think that as we could be using this device simply for heat generation (possibly to provide power via turbines etc.) all we need to achieve is power output of any kind . The electrical power input could be utilised on top of this output power to produce an efficient heat source.
Really all we need to achieve is continuous operation to have a possible power source.
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 04/06/2007 02:13 PM
Quote
colbourne - 5/4/2007  10:35 PM

Are we setting our sights too high.
We are trying to achieve power output of more than the power input.
That's not setting our sights too high; that's the whole point.  And Dr. Bussard's results indicate that this won't be too hard to achieve.

Quote
I think that as we could be using this device simply for heat generation (possibly to provide power via turbines etc.) all we need to achieve is power output of any kind . The electrical power input could be utilised on top of this output power to produce an efficient heat source.
Really all we need to achieve is continuous operation to have a possible power source.
No, to produce a power source you have to get more power out than you put in.  And as a heat source, it's rather pointless — generating heat is  far more easily done in dozens of other ways.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/06/2007 08:20 PM
One question would be with the original WB-6 machine or equivalent.  Dr. Bussard had claims for the loss levels of that machine using Deuterium fuel.  However, what if he were to use Deuterium Tritium fuel.  How much would that increase the energy output of that machine?

Yes, I know that with the DT reaction, the reactor becomes highly radioactive very quickly and degrades very quickly and the neutrons which have all of the output energy are a pain to deal with.

But, if that can be shown to generate net power output for even a few minutes with a very inexpensive machine, something that ITER may or may not be able to do for several billion dollars.  Maybe that would spark a lot more interest and hopefully funding for this process.

The holy grail would be the pB11 reaction, but I'm sure that a straight DD process would still be a very welcome machine.  Who knows, perhaps in the long run DD machines might have a niche market.  If you need the smallest possible reactor possible, but it only has to run for a couple of minutes....  Surface to LEO launch of SSTO comes to mind.  Who knows, perhaps a DT machine about the size of
a falcon 1 rocket, but 70% payload launch mass...
Title: Re: Fusion with space related aspects thread
Post by: palebluedot on 04/06/2007 09:51 PM
Just as long as the WB7 and WB8 machines are convincing, and the people in charge are convinced by them (doesn't necessarily mean the same thing, unfortunately), I'm certain both DD and pB11 will get done in one way or another. But if the machine works as advertised, wouldn't pB11 be pretty simple to do? Just crank up the juice to create a deeper potential well, and maybe up the radius for bigger gain so you get it self sustaining. Suppose you get all the physics proofs you want and more from WB8, is there any point in wasting time with the DD machine at all? I think they should go for the holy grail directly. DD or something like it could be used in space as direct fusion propulsion or something like that.. pB11 should be priority 1.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/07/2007 04:38 PM
Well, yes pB11 should be a priority as long as people with deep enough pockets are convinced that it is possible and they are willing to fund it.

Until that point has been reached, and it may very well already have been reached, it's still at a proof of concept stage.

The two reasons that I'm suggesting DT are the following.

1) Using DT a short demo with a really cheap machine would be able to say, we can already do more than ITER, but on a shoe string budget and 10 years before ITER is even built!!!

So, this would definitly attract attention and possibly further fianincing.

2) A DT machine might have niche uses.  An example would be where a really small power source is needed.  And a DD fusor would be too big.  Now granted the size range where it's big enough to run DT and too small to run DD is a fairly narrow range.  So this would be a really small niche.  Perhaps a mini sub for the NAVY.

The other question is how long can you run a DT reactor without activating it too much?  Or could you build a DT reactor out of materials that tend to be resistant to getting activated?  Remember that for a DT reactor that only has to run for a short period of time, it might not have to breed it's own tritium.  You could breed that ahead of time externally.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 04/08/2007 08:19 AM
Here is an excerpt from a letter by Joel Rogers to a friend of mine at Boeing. I hope Tom can explain about the confidential report from Bussard and what he knows about funding the project at Los Alamos when he gets back from vacation.


From: Joel Rogers <--------------------->
...
Thanks for the inspirational piece from Tom Ligon. He is Bussard's most
effective disciple at present. It helps that he is a good writer. That is just
what the project needs at this point.

Ligon has submitted a paper to the ISDC Conference in Dallas in May. He says
Bussard asked him to go there to pitch the project.

I have been poring over Ligon's many blogs in fusor.net. He is very prolific and
quite well informed. He says Bussard sent him a confidential report on WB-6 and
since then Ligon divulges what he knows is not secret. That will do for now. I
have lots of downloaded fusor.net material to study, including a reprint of
Bussards 1989 patent.
 
Another positive note. I contacted my neutron detector expert friend at Los
Alamos and he contacted his fusion power friend at Los Alamos and that friend of
a friend said he said that the project deserves funding at the $10M level.
Progress. I haven't talked to that fusion guy yet, but I will call him and ask
permission to use his name. If he goes on record, he will be the first expert
witness on our side, I think.
 
Take care, Good Buddy.

Jay
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/09/2007 02:33 PM
I'm back "on-line" after two weeks bobbing about the Caribbean.

PaleBlueDot ... In principle, going to p-B11 just means jacking up the voltage.  A serious question is often raised about this ... will the higher voltage required result in excessive bremstrahlung "braking" radiation?  DT and even DD reactors would probably work at a low enough voltage that this is not a concern, but p-B11 requires that it be addressed.  In the absence of ions, the electrons converging at the center of the device form a virtual cathode (attracts positive ions, repels electrons), and this would cause the braking that results in the radiation.  But with ions present, those converge to form a virtual anode.  Control of the virtual anode height is necessary in order to control bremstrahlung, but in principle, it should work, and the physics are straightforward.  This calculation is an essential part of the existing model of the device.

BarryKirk ... I see no reason why one of these machines would not burn DT with a vengance.  Nearly all the energy would be produced by neutrons at something like 13 MeV, so the method of exploiting it would probably be a lithium blanket some meters thick, as for the large tokamaks.  That, plus the steam cycle equipment, would almost certainly offset any size advantages of the reactor itself.  Either of the neutron-producing reactions would probably also be rough on superconducting magnets, so they might have to work with copper magnets.  Bussard's earlier work on the "Riggatron", a copper-coiled tokamak with the coil located inside the lithium blanket, suggested that net power reactors would probably limit the coil life to a couple of months, but the power produced would have still allowed profitable operations.  

The neutron-producing fuels will make the easiest reactions, and they will make useful powerplants if p-B11 cannot be made to work, but they are necessarily nasty.  With the p-B11 demo reactor only projected to cost 1/3 more, and the benefits so outstanding, that would be my first choice.  If, for any reason, the demo plant could not run p-B11, it should certainly light off a furious reaction with DD or DT.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/09/2007 09:41 PM
Yes, that's what I'm talking about it would burn DT with a vengence.  Would a WB-6 class machine or something slightly more advanced be capable of DT reaction?

The reason i'm asking is this.

If Dr. Bussard can create such a machine for 2-3 million dollars in 2-3 year time frame and run his DD tests on that machine.

Than after collecting his data on that machine, as a last step, run it with DT.

If he can show 10 minutes of net power production that blows ITER out of the water it would certainly grab a lot of attention and possibly investment.  Hopefully, he won't need it at that point.

For that short a test, no lithium blanket would be necessary since you don't need to breed fuel.  Yes, your coils would probably be shot after the test, but who cares.


As for niche applications where DT might be useful.  Here is another possibility.

For use on earth to LEO booster rocket.  If you can generate sufficient power from a small package and don't care about spraying neutrons all over the place....  Perhaps just using the reactor as the second stage of a rocket.  At that point the neutron source is turned on high in the atmosphere where it is already moving really fast.  To protect the payload, put the payload on the far side of the fuel tank and use the fuel as shielding and/or have the fusion rocket in the form of a tug, with the payload being dragged along with a cable.  If the cable is say 400 to 500 feet long and if the reactor spews out neutrons in all directions equally.  Then inverse square law says the payload will only intercept a small percentage of the neutron flux.  Since the reactor only needs to run for a few minutes, the total neutron absorption by the payload might not be too bad.

Again, that would be an extremely small niche market.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/10/2007 03:05 AM
Going to DT instead of DD would probably boost the reaction about a factor of 30-50, if I read the crossection curves right.  It would make the fusion considerably easier to detect, but would not make net power in a machine the size of WB7 or WB8.  If WB8 were, as expected, better by a factor of 3 over WB7, adding DT would give 2 orders of magnitude when something like 7 orders of magnitude is needed for net power.  You need the increase in both size and magnetic field strength.  But a DT machine could be made somewhat smaller than a DD machine, about 62% as large if R^7 scaling is used.

A factor of 30 is a nice advantage, but obtaining a tritium license for one test would be a real pain.  And obtaining tritium without a license gets your name on a list that gets watched very closely.  There are small-scale legitimate uses for it, but it is a bomb-making material an also very dangerous biologically.  Deuterium is available without license, and is much safer to handle.

The neutron propulsion idea is intriguing.  Looking at some of the "old Orion" ideas, the old nuclear-bomb propulsion proposal, every version I've seen used a "coating of reacton mass" on the bomb and also a layer on the pusher plate, and in each case the material chosen was a good neutron moderator.  It is clear to me that they wanted to use the substantial energy of the neutrons.   For a DT reaction, the energy output is almost entirely from a hellish neutron of about 13 MeV. But I think you can't just stick the reactor attached to the rocket behind a pusher plate.  Neutrons leaving rearward will cause low thrust at extremely high Isp.  It might be possible to run the rest (most) of the neutrons into a moderator that is heated sufficiently to either heat a reaction mass like hydrogen or water (both good moderators) for thrust, or simply waste that energy once the available reaction mass is spent and simply accelerate gently on neutron thrust and waste reactor ash.

Some materials are reasonably good at "reflecting" neutrons ... I don't know if that includes 13 MeV bashers, but if so you might actually reflect most of the neuts out the back of the ship, and that would make a very high Isp engine.  But it would be necessary to have high life expectancy from it to achieve decent velocity.  Possibly you would simply carry a lot of MaGrids.  They're light and might be cheap enough.

I've posted references elsewhere on the forum to designs Bussard has published that should be more efficient, but enough high-energy neutrons ought to be able to make some thrust.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/10/2007 05:06 PM
Well, an increase in power of a factor of 30 is a nice advantage, even if the efficiency were to go to say 10%, that is still an increase in effective power of 3 to 1.

As I said, I'm looking at high thrust, lower ISP stuff to achieve LEO.  Perhaps a DD or pB11 reactor could be fed a diet of DT for 15 to 20 minutes to reach orbit.  Once there, it could be reconfigured for DD or pB11 reactions at low thrust and super high ISP.

As I said iniitially, pB11 is really good for power production and most applications, but there might be a few small niches where temporary DT burning might useful.

Kind of like the afterburner on a fighter plane.  You don't use it all the time.  Just for short bursts when you need it.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/10/2007 05:30 PM
How about using a water blanket around the reactor to produce steam for high thrust then converting to electronic drive for long missions.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/10/2007 06:40 PM
The practical form might be a graphite shell around the reactor thru which water is fed to make steam (both are good moderators, graphite better).  That would concentrate the heat production for steam.  Store the remaining water around that to capture the remaining neutron energy.  

Unlike a fission plant, you don't need to worry about loss of reactivity when the reactor is hot, etc, so it might well out-perform comparable fission designs.  Should throttle as fast as you like, too.  With no thermodynamic cycle, it may be the most light and compact Polywell propulsion system.  

I can also see the possibility of switching to hydrogen reaction mass once clear of the atmosphere, to boost Isp.  That's tricky in a fission plant because it means changing the moderator behavior which will change reaction rate, but it won't affect the fusion reaction.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/10/2007 08:26 PM
Tom, a few questions:

I've been reading posts here and at fusor.net for a month or so, and I'm a little confused about your role in research at EMC2.

Were you working for Bussard in the past?
Are you a scientist or a technical writer?
What are your academic degrees?
Are you still working for Bussard or are you volunteering?
How can you represent Bussard and/or his research at a conference such as the International Space Development Conference in your current role or capacity with respect to EMC2?
I don't see your name on the list of speakers, are you still going to ISDC 2007?
Focus fusion seems to have more support, from countries such as Peru.  Why is that?
When Helium ions are ejected from the core, won't they hit the magnets?
My estimate is the He ions have 0.2 probability of hitting the rings based on cross-sectional area.  Won't that dump a heck of a lot of heat?
Won't the cladding, or whatever is protecting the magnet rings be damaged?
Is this what caused the catastrophic failure in Bussard's last experiment?
Private sector is often based on hype, is that what we're seeing here and in the Google video?

Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/10/2007 10:28 PM
SemperUbiSububi,

I've been lurking on the fusor.net site also and I think I can answer some of your questions.

When Helium ions are ejected from the core, won't they hit the magnets?
My estimate is the He ions have 0.2 probability of hitting the rings based on cross-sectional area. Won't that dump a heck of a lot of heat?

Yes, some of the helium ions will hit the MaGrid.  With an energy in the Mev range they will have the energy to escape the potential well.  With a high mass to charge ratio, they are ions not electrons after all, they will barely be deflected by the mag field so if they are pointed at the MaGrid initially, they will hit it.

There are some methods that can minimize the number of helium ions that hit the MaGrid, but when the ions do hit the grid they will dump a tremendous amount of heat.  If the coils are surrounded by a jacket and liquid cooled, some of that heat can be removed and possibly used to power a steam cycle.


Won't the cladding, or whatever is protecting the magnet rings be damaged?

Possibly, it could be damaged.  The nice thing is that since alpha particles don't pentrate, it would only be the surface that would be damaged.  And since these particles aren't neutrons, they won't make anything radioactive.  Turn the polywell off, and the rings could be replaced and/or removed within minutes.

Is this what caused the catastrophic failure in Bussard's last experiment?

The failure in Bussard's last experiment was due to Paschen arcing.  I think, and Tom can correct me if i'm wrong on this one, that is when neutrals outside of the MaGrid become ionized and provide a current path to the outside surface that bleeds electrons out of the system.  Since there is a current flowing, that caused heating which melted some of the insulators in the MaGrid.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/10/2007 10:44 PM
Yes, thats it.  A NERVA style rocket.  That's a good idea changing the reaction material in mid flight.

That would be a nice trick... Without staging you could transition from a high thrust lower ISP to a lower thrust higher ISP system.

Also, if the engine bell is made of a material that can reflect neutrons.... If that is possible with that high energy neutrons, You'd have slightly more neutrons coming out the back than the front and with that kind of velocity, it would make for a huge ISP.  Of course the total thrust from that effect would pale compared to the thrust from the reaction mass.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/10/2007 11:26 PM
I worked for Dr. Bussard from late 1995 to early 2001.  I still believe in the program.  I am a technical jack of all trades, which was my role at EMC2 when he could only afford one guy in the lab.  I'm volunteering now in order to help a dear old friend see his dream of saving the world come true.  When I left the program, he told me I would remain unofficially on staff as the "company scribe", in case there were ever any news to present to the world.  I have, with his blessing, submitted a fact article on the project to Analog Science Fiction and Fact about a month ago.

I hold BS degrees in both Electrical Engineering Technology and Biology, with an option in Health Physics and undergraduate research in chemical kinetics.

I have been a technical writer and I'm a life member of the Science Fiction Writers of America.

Dr. Bussard was approached by someone at ISDC to give something like the Google talk there.  He declined due to his health, but asked me if I could go (I have both written and given talks about inertial electrostatic fusion in the past).  I had been planning to make a donation to his NPO, but now I'm using the money to go to the conference instead.  

As of last night, I saw that I'm a scheduled speaker at ISDC, but I'm not on the list of high profile speakers.  I just paid my fee and NSS dues last night.  I was a NSS member for a while by virtue of getting sucked in with the L5 Society.

I've seen Focus Fusion's website.  Looks like they may be using something like Paul Koloc's spheromaks for their plasmoids.  I know Dr. Bussard and Paul know each other, and Bussard thinks spheromaks may be able to do some fusion.  Beyond that ... all I can say is p-B11 is pretty ambitious for a Maxwellian approach, but I wish 'em well.  Dr. Bussard has only been after private funding for under a year at this point, and only went public with the results about a year ago when it became obvious he was not going to get more funding from the old sponsor (who had required that he not publish anything).  BTW, I notice Focus Fusion found Dr. Bussard's results and were favorably impressed, and consider him about even with them!

Yes, some of the fusion products will hit the magnets and if there's a 100+ MW reaction going on it is going to cause all the effects you say.  Lots of fun for the engineers.  But realize that any fusion reaction chamber must deal with this sort of thing.  I expect a water-cooled inner shield will be used (maybe steam energy can be recovered), a vacuum gap, LN2 jacket, another vacuum gap, and liquid helium.  The water jacket should take the worst of the load.  With p-B11, alphas won't penetrate the first shield.  It will probably be replaced often.

WB6, WB3, and WB2 all died by coil shorting.  On the first two, I think we may not have used the best grade of insulation for the high temperatures.  This problem can be overcome ... Toni Rusi just called me with an idea similar to something I saw recently from someone else ... a high-temperature embedment method of constructing magnets may work.

Dr. Bussard is definitely milking his little bit of data for all it is worth, but he's being very honest about the data ... he put raw results in the Valencia paper instead of glitzing up some graphs.  He knows more than anyone that he needs the WB7/8 experiments to generate replicate results over a much longer time period.  It is not hype.  The machine definitely was doing DD fusion at an amazingly high rate for an electrostatic acceleration method running at only a 10 kV potential.  The results were on-track with what the theory always said it should do, and it replicated on several tests.

I like to compare this to the development of the internal combustion engine.  Imagine someone like Otto cranking an early prototype, and getting it to fire a few times when he dropped some alcohol into the intake.  On the fifth run, imagine the piston cracked.  A skeptic would scoff and ask why anyone should be interested in a noise-maker that wastes perfectly good booze.  But Otto knew he had proved that the concept that would power the future basically worked.

 



 :)
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/10/2007 11:29 PM
BarryKirk, you do realize, I hope, that NERVA is the final version of the program that was originally called ROVER.  That program was based on Dr. Bussard's proposal (at age 24), and he basically designed the KIWI A engine.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/11/2007 01:38 AM
For Bussard's reactor design, the fusion power scales with the cube of the radius, but the magnetic ring section area scales with the square of the radius.  Am I wrong?  There is a maximum size for this reactor, above which cooling is impossible because no material can withstand the heat (watts per square meter).

I guess the obvious questions are:

At what size does the reactor dump so much heat into the rings that they melt?

Will it produce net power at a smaller size?

Will it produce net power at a competitive cost at that smaller size?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/11/2007 02:44 AM
The problem with graphite is cooling. It is a poor conductor of heat. Moderating neutrons will generate heat.

A better approach is a metal shell (stainless steel probably) enclosing a water moderator. Then almost all the neutron energy produces thrust.  Plus the moderator is effecively self cooling. Not to mention cooling the metal shell very well.

In addition any moderator will act as a reflector of neutrons adding a fairly high ISP component to the thrust.

Once you get into space cooling is a very big problem. As I'm sure you understand.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/11/2007 12:47 PM
I knew about KIWI and I've heard about ROVER.  I had forgotten that Dr. Bussard was involved in it.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/11/2007 12:48 PM
Well, you can make the reactor arbitararily large.  You may not be able to run it continously though.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/11/2007 12:51 PM
The reaction mass can be the coolant.  Hydrogen cooled chemical engines have been around for a while.  The chemicals suggested in earlier posts for cooling are hydrogen and water.  Both are excellent coolants.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/11/2007 04:56 PM
There may be a maximum practical size for a more fundamental reason that could prevent even pulsed operation.  Because the ions must cross the bulk of the MaGrid interior with little chance of collision, with high density only at the outer turn-around zone and the central convergence zone, a radius on the order of or above the mean free path at the needed density would be excessive.  

I know of no practical limit to the number of these things that could be put in a single powerplant or spacecraft, however.  Most of Dr. Bussard's spacecraft concepts employ two reactors and thrust generators ... for redundancy if no other reason.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/11/2007 05:24 PM
MSimon ... regarding graphite and cooling, I'm not sure graphite is necessarily all that bad at conducting heat.  Russian nuclear power plants use it, and I know early British designs did as well.  Not that Chernobyl and Windscale are exactly beloved names in the industry.   The Rover KIWI reactors were graphite moderated.  It is possible to water-cool graphite effectively.  

Carbon fiber brakes are, if I recall, highly heat-conductive along the fiber directions.  As long as you don't add anything deleterious to neutrons to them, I see no reason why carbon fibers should not make a good moderator.

My thinking is that in order to use the steam effectively, it needs to be channeled.  In a weightless environment, heating a tank of water provides no place for a steam head (although this is not so much a problem once you're under thrust).  But metals are ususally a neutron poison, so I was figuring graphite as a stable, solid neutron-energy-grabber for bulk of the steam generator.

But whatever gets the reaction mass out the back is fine with me.  You guys build it.  I'm expecting relativistic electron beams powered by p-B11 to be on the back of my asteroid belt freighter.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/11/2007 10:05 PM
I'm a Naval Nuke kind of guy so I know a fair bit about reactor design.

Cooling carbon requires a lot of plumbing.  In a space vessel you want things really simple. Keeping the cooling tubing in contact with the carbon in high vibration environments would be a design challenge. Not to mention that carbon is weak and brittle.

Carbon might make sense if you needed to conserve neutrons for other processes. Like for instance fission.  In fission reactors  you need to conserve neutrons.  The fuel is clad in zirconium rather than some kind of steel for that very reason. However, the reactor vessel through which all the "excess" neutrons (about 50% of neutron production) leak is  made of stainless steel. They are designed to handle a high flux of thermal neutrons and a small flux of high energy neutrons for 50 years of continuous operation. BTW the vessels are designed to operate continuously at 2,000 psi including a number of heat up/cool down cycles and pressurization cycles.

The induced radiation declines to serviceable rates within 10 days of reactor shut down. (I don't remember if it was induced radiation in the SS that was the problem or fission products in the reactor - in any case 10 days is an upper bound).

You get the thrust you want by throttling. On the pad you feed the rocket a steady flow of reaction mass during warm up and then switch over to internal mass on take off. Water is probably better as reaction mass because venting massive quantities of hydrogen on the pad at take off would be very hazardous on earth. In space hydrogen  with its higher ISP might be better. You do have the problem of keeping it around for long duration flights.

BTW the Space Shuttle main engines are basically water engines. I'd have to look up at what pressure/temperature they operate at , but obviously a lot of work has been done with high temperature water as reaction mass.

Let me add that about 1/4" of water is all it takes to thermalize high energy neutrons. So the water jacket of the reactor need not be especially thick. You pump the water into the jacket as needed.  A relatively small fuel/oxygen turbine running the turbo pumps would probably be the way to go for take off to orbit pumping. For de-orbiting with its more reasonable time frames, an electric motor driven pump could do the job.

If we can get the Bussard design working we will be going into space with steam engines. Watt would be proud.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/11/2007 11:22 PM
I just looked up the Shuttle main engine pressure and it is around 3,000 psia in the combustion chamber with about double that pressure in the fuel feeds.

Not too tough.  Doubling the engine pressure might be feasible due to the lower temperatures involved. That would double the effective ISP lowering the required reaction mass. Saturated steam at that temperature/pressure has the same density as liquid water at that temperature/pressure (i.e. it is above the critical point).

The water jacket would probably be a two layer affair. An outer layer producing saturated steam and an inner layer producing superheated steam.

Since there is no need for combustion, the cooling problems of the engine would be relatively easy to deal with.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/12/2007 12:31 AM
Yeah, I guess I'm so used to moderators that I just went that way, but it was nibbling at the back of my mind that it just matters that you get the heat out of that 13 MeV sumbitch.  Heck, slam it into a poison!  Optimize the material to hold water and steam and transfer the heat to that.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/12/2007 11:38 AM
Not only would Watt be proud.  So would Isaac Asimov.  In some of his early science fiction, he used steam rockets and I believe that he heated the steam with nukes.

Yes, hydrogen would be excellent at thermalizing a neutron because the mass of a single proton is the closest mass to that of a neutron.

The best method of drawing off energy of a particle using a an elastic collision is to have it collide with a particle of the same mass.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/12/2007 02:58 PM
The problem with hydrogen is that unless you are using liquid hydrogen it is hard to get the density up. If you are using liquid hydrogen then you get into having to deal with cryogenics.

Water is a very good moderator because for most collisions it does not act like a particle of atomic weight 18. Most neuton collisions send it spinning.

In any case a thermalizing distance of 1/4" ( 500 to 600 deg F water at 2,000 psi) is not a problem.  The channel for the water would have to be thicker than that to get the required mass flows without excessive pumping losses.

Tom's point about a restart in space (get the water to the top or bottom of the tank for pumping) is also not a problem.  You just vent some water into the engine from the water tank for a little initial thrust.

In addition the water tank would make a nice zero extra mass radiator for internally produced heat. It would not be very efficient but it wouldn't have to be because the excess weight penalty would be zero. Because you are not dealing with cryogenics the tank could be the wall of the vehicle. In addition the heat (cooling electronics, on board eqpt.  etc.) would keep the water from freezing. If you kept the water in the tank at  80 to 90 deg C it might make a good (if inefficient ) attitude adjustment system. Eliminating all that dangerous hydrazine stuff. The advantage again is that the amounts reqiured (even accounting for the ineffiency) are miniscule in relation to the reaction mass.  Another way to do it would be to use the reactor to  keep the neutron blanket hot  and pipe the hot water to the attitude adjustment system. Or use electric heaters at the attitude adjustment system nozzles to raise the water temperature. Then you get an attitude adjustment system with variable thrust.

The whole rocket system  becomes just one big plumbing problem.
Title: Re: Fusion with space related aspects thread
Post by: TyMoore on 04/12/2007 04:33 PM
Quote
M Simon - 12/4/2007  7:58 AM

The problem with hydrogen is that unless you are using liquid hydrogen it is hard to get the density up. If you are using liquid hydrogen then you get into having to deal with cryogenics.


Uh, water actually contains 1.6 times more hydrogen per unit volume than does liquid hydrogen:

(1 m^3 water) * (1000 L/ m^3)  * (1000 g/L) * (1 mole H20/ 18 g) * (2 mole H/ 1 mole H20)  * (1 g H/ 1 mole H) * (1 Kg/1000 g) = 111.1 kg


density of liquid hydrogen is about 70.7 kg/m^3


111.1/70.7 = 1.57

Ironically, one can ship more hydrogen in the form of water than you can with an equal volume of liquid hydrogen--provided of course you don't mind the weight penalty of hauling around the oxygen too! Perhaps the p-b11 fusion propulsion system will enable efficient transfer of hydrogen from comets by shipping megatons of water!



Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/12/2007 05:33 PM
Couple of points.  Once in LEO, high thrust is no longer required.  At that point efficiency and ISP are much more important than thrust.  The whole idea of using a DT reactor that spews neutrons is just for a short time to reach LEO.

Once LEO is reached, switchover to pB11 and super high ISP super low thrust stuff.

Prior to LEO thrust is king and again, this is a variable.  At the very lowest stages of the boost to LEO thrust is much more important and ISP has very little value.  As one approaches LEO, thrust becomes less and less important and ISP becomes more and more important.

I'm going to make the assumption that even a DT reactor is going to be running at much lower temperatures than the space shuttle main engine or even the RS-68 engine.  With steam coming out the
back, that is going to make for lower ISP than a typical LOX LH2 chemical engine.

Because water does have a high density, I'm guessing that the thrust to weight ratio won't be too terrible.  Probably not as high as the Space Shuttle Main Engine or even the RS-68.

So, at liftoff, one has an engine with lower efficiency and thrust to weight ratio than a typical LH2 LOX chemical engine....

But, the beauty of a polywell based engine... I'm hoping, cause nobody has ever built or designed a polywell rocket engine, is that you can change fuel on the fly without staging or changing engines.

Now going to a pure LH2 fuel at the same temperature jumps the ISP by a factor of 3 to 4.  That's huge!!!

Now your talking about ISP in the 700 range!!!!  That almost double what can be done with the best chemical engine.  That is what will give a tremendous boost to payload mass fraction to orbit.

You could probably do this as a continously variable where you gradually switch over from pure water to pure LH2.

I'm not sure what the max temperature that such an engine could be run at.  NERVA ran cooler than the RS-68 chemical engine.  

I'm sure engineers will have fun getting creative trying to really boost that max temp.  A real jump does occur at the temperature at which LH2 disassociates into monatomic hydrogen.  If it is possible to run hot enough to disassociate water to hydrogen and oxygen, then really high ISP could be acheived with water.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/12/2007 09:09 PM
Sodium Borohydride (Na-B-H4) has been proposed as a fuel.  It is a solid.  It is also miscible in either water or methanol so it can be moved via pumps.

I'm not a chemist but perhaps it can be electrolyzed to obtain both hydrogen and boron.  There must be a reaction that liberates the hydrogen and boron for the fusion reactor and also yields a vapor of sodium metal for ion engine propellant.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/13/2007 12:31 AM
Only 700 seconds?!  Dr. Bussard told me even KIWI A could hit something in the mid 850 second range, and it was intended to launch ICBMs.  It used hydrogen for reaction mass, but if hydrogen could develop booster thrust, I'd bet water could develop the higher Isp, with a sufficiently perky heat source.

I'm sure it is possible to change a p-B11 polywell to DT and get a vigorous reaction, but it is probably bad for the reactor.  High neutron flux is probably damaging to the expensive superconductors in the MaGrid, and all the direct conversion equipment would simply be in the way.  Plus, the p-B11 reactor is larger than needed.

I was figuring the DT reactors would be specialized, probably more compact and possibly optimized for shorter life.  They may used copper coil MaGrids.  They would be used when you don't want to launch a machine with a pair of 12-meter diameter reactors.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/13/2007 12:58 PM
I was too lazy to google up the specs on KIWI A and NERVA so I was going on my faulty memory.

850 seconds is incredible.  I did a cursory goggle for the dissassociation temperature of Hydrogen and found that at different temperatures you will get percentages of diatomic and monatomic hydrogen.  At
5000K you get 95% monatomic hydrogen, but I'm sure it would be difficult to reach that temperature without melting your engine.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/13/2007 03:03 PM
I'm sure.  Keep in mind, the chronic problem with the hydrogen-cooled fission rocket engines was that they tended to erode the hydrogen channels, spew off chunks of fuel, vibrate, and otherwise show indications that they were being run as hard as the researchers thought they could possibly stand.

Pretty much SOP for boosters.  If it is not incredible that it can operate at those conditions, it is overdesigned.  Good thing this planet is no bigger than it is.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/13/2007 05:52 PM
The best way to handle this question might be to electrolyze water. Breathe the O2 and use the H2 as reaction mass. Or just pitch the excess O2 over the side depending on the trade offs.

About a lb of p-B11 should be enough to get 100 MW for a day. That would be 24,000 MW for 6 minutes. Or 12,000 MW for 12 minutes.  About the same (i.e. insgnificant vs vehicle mass)  vs  D-D fusion (desireable from an accident stand point vs D-T). The  required fuel amounts are not significant re: vehicle weight.  In fact variations in passenger weights will put the required fuel amounts in the insignificant range even counting tanks to if you keep the D2 as a gas.

D-T fuel picked up on the moon might work from an environmental standpoint. At least for work around the moon. Accidents might be another question.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/13/2007 06:43 PM
That is very true, it is a good thing that this planet is no bigger than it is.

I've looked at people talking about scooping hydrogen out of the atmosphere of Jupiter and thought, "That's absolutely nuts!!!".

I'm not saying that hydrogen isn't difficult.  I'm just saying that the only way that a fusor based steam rocket for surface to LEO makes sense is the following two scenerios.

1) Your only running steam for the first minute or two and then switching over to hydrogen.  IE a variable thrust to weight and ISP engine.

2) You can run the fusor engine at a significantly hotter temperature than a chemical engine.

Option 2 may be more difficult than just using hydrogen.

If LH2 was causing those problems with erosion etc at 850 seconds.  Would it be easier to run such an engine at 700 seconds ISP?  It would still have significant efficiency advantages over any chemical engine.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/13/2007 08:56 PM
Actually, we may be killing ourselves here by thinking like big dumb booster guys.

Big dumb boosters need to take off straight up and get into orbit fast because standing on your tail is inefficient.  With impulse propulsion, the less time spent under thrust, the better the efficiency.  As long as we can keep the reaction mass flow going long enough, we can do it with a thrust to weight ratio well below 1.

In fact, with nuclear, the length of burn time is not so limited.  We can use the alternative strategy of horizontal takeoff and more horizontal flight,  powering an aerospace plane.  Not so much thrust required.

Dr. Bussard's dream Earth-to-LEO craft is a p-B11 reactor driving a relativistic electron beam into an airframe cavity such as would be used on an external combustion scramjet.  It would use the atmosphere for reaction mass, then switch to water to make orbit and circularize.  I think he was looking at 1200 sec for that.

Oh, the possibilities are simply ENDLESS!  There are so many things you can do with this power source to make rockets, the pain is going to be deciding the best.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/13/2007 09:23 PM
How often is Bussard planning on putting out news reports?  It'd be hugely beneficial for him IMO if he did what John Carmack did, posting weekly reports on his website.  More to the point, it would be hugely beneficial for his fans IMO to get more insight into the science and technology and what's involved in it's development.  I suppose there are patent issues, but it is rather exciting for spacecases like myself.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/13/2007 10:02 PM
Quote
Tom Ligon - 13/4/2007  4:56 PM
Actually, we may be killing ourselves here by thinking like big dumb booster guys.

Well, yes and no....

Let me use the Falcon 1 as an example.  The first stage lights up and burns for 169 seconds.  At the end of that 169 seconds altitude is 297,000 feet.

Velocity is seriously supersonic and altitude is above 98% of the atmosphere.  When the second stage lights
up.  The initial acceleration is slightly less than 1 G.  That acceleration quickly rises to above 1 G and if i'm
not mistaken, eventually reaches about 3 Gs at the end of the burn.

Using a Bussard rocket and horizontal takeoff, we are talking about wings which seriously reduces the thrust
requirements for the engine as long as you are in the atmosphere.

My concern is not with the beginning of the flight and not with the end of it but rather the middle of the flight
envelope.

At the beginning your low in the atmosphere and wings can generate a tremendous amount of lift.  High
thrust isn't really required to get off the ground.

At the end of the LEO insertion, the velocity is close to orbital, so gravity losses are minimal.  Correct me if
i'm wrong, but gravity losses are proportional to the square root of the difference between current velocity
and orbital velocity.  So as one approaches orbital velocity, gravity losses drop and you suffer less and less
of a penalty for low thrust.

It's the middle of the flight envelope that concerns me.  At some point your going too fast to stay in the
atmosphere because of the thermal loads.  At that point your wings can't generate any more lift.  The
problem is that I think that point will be reached long before you have enough velocity to reduce the gravity
losses to a small amount.

Now you mentioned 1200 seconds out of a water based relativistic electron beam p-B11 reactor.  That's a
huge ISP.

Let's say that you can use your airframe scramjet to achieve 1/2 orbital velocity before leaving the
atmosphere.  That's a tremendous thermal load, but lets say that can be achieved.

At 1/2 orbital velocity the net gravitational acceleration towards the earth is still 0.7 G.  If your 1200 ISP
rocket can't develop 0.7 G acceleration, it won't reach orbit no matter how long you can maintain thrust.

In fact you need to acheive 3/4 orbital velocity before the net gravitational acceleration towards the earth
drops below 1/2 G.

I'm assuming that the relativistic electron beam into an airframe cavity can generate a lot of thrust even in
very thin air.  If that's not the case, then you'll have trouble reaching even 1/2 orbital velocity before
leaving the atmosphere.

The potential for a Bussard rocket engine to explore the solar system and very possibly send people on
interstellar missions is real and exciting.  That is a dream!!!

Earth to LEO is a real pain.  That is why I've been looking at higher thrust to weight ratio alternatives.
Once LEO is achieved, than thrust IS meaningless and ISP is king.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/13/2007 11:57 PM
JP Aerospace already has plans for an Airship-to-Orbit.  It would reach a very high altitude using high efficiency props, then switch to ion engines.  Their platform might be a safe way to fly a large and expensive fusion system.  Most typical aircraft probably don't have the tonnage to carry a massive fusion reactor.  Airships might.

I don't have much faith that it would happen, considering that the demo reactor Bussard is proposing would cost $300 million.  Energy production might suggest future revenues, but I don't know if cargo transport or passenger flights to orbit would pay for the cost of the spacecraft.

If it did work, when it reaches orbital velocity it could deflate and stow most of its bulk.  Then fly to Mars.  Or tour the solar system.  Upon returning to Earth, unfurl its airfoil, inflate and re-enter the atmosphere at some really really low angle.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/14/2007 01:59 AM
$300 million includes engineering, testing, and tooling for the first reactor.

The price comes down with experience.

I think going from mWs of energy to MWs is way too ambitious. There needs to be intermediate steps if for no other reason than to test the engineering and cooling etc.

1 W

1 KW

100 KW

1 MW

10 MW

100 MW

would be a good progression. (step size adjusted with experience).

Overlapping constrution might shorten the time with acceptable risk.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/14/2007 02:35 AM
The fusion reactor is not going to be very massive (neglecting cooling rqmts).

You need a reactor vessel  3m  across  with an equivalent  thickness of 1/2" to 2" (1.2 cm to 5 cm)

Area = pi * d^2 ~= 30 sq m.

1.2 cm = .012 m  = .36 cu m
5    cm = .05 m    = 1.5 cu m

density of steel = 8g/cc = 8,000,000 g/m^3 = 8,000 kg  ~= 9 tons/m^3

1.2 cm ~=   3 1/4 tons
5.0 cm ~= 14       tons

Then you have to add in the auxiliary eqpt. Insulators. Pumps. Magnetic coils. etc. Probably an equivalent mass.

Efficiency to orbit is no big deal. Fuel is cheap. Reaction mass is cheap. The main addition would be to the capital cost. i.e. a bigger water tank. Bigger pumps. Bigger diameter engines. Larger minimum thrust. Should not be a big deal.

We can improve efficiency with experience so long as the first one works.

First we get the simplest system. Then we can experiment with fusion powered scramjets and all the other goodies.



Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/14/2007 03:32 AM
MSimon, that may sound like a nice progression of power levels to you, but you are evidently not in your late 70's and dealing with health issues.  Dr. Bussard is tired of messing around and wants to know this thing is going to work.  And, based on the work so far, he fully expects it to.  We'll see if any investors bite.

BarryKirk,

A very long time ago (the computer model number was in Roman numerals) I set up and ran a simulation of a fictitious craft called a "Sunfire".  It used a mysterious electric power source of about 40 MWe, powered by fusion.  It used magnetohydrodynamics to develop thrust from air.  The craft has been used in a couple of stories I've published.

This was all long before I met Dr. Bussard, so you can imagine I was practically giddy when I saw his version of it.

The working assumptions of the model were:

The power level was supposedly equivalent to a particular existing jet aircraft.

The basic drag figure of merit was based on known performance of that jet aircraft at something like 45000 ft.

Max Q was assumed to occur at Mach 3 and 80,000 ft (the SR71 can withstand this).  That gave my my midpoint.

Orbital velocity was sought at around 70 miles.  Thrust at that point was quite feeble, but so was drag.

Drag scaled as ro v^2.

Air density dropped with altitude per a standard formula.

Gravity dropped as velocity increased, so the required aerodynamic lift was reduced, in turn dropping drag.

The model kept the throttle down until above the max Q altitude and speed.  Once above that altitude, I adjusted throttle and/or climb to maintain no greater than that dynamic pressure.  Once the craft would no longer hit max Q, I simply let it climb at full throttle.

This little ship consistently hit orbital velocity and 70 miles at about 3/4 of the way around the equator, on air alone.

The basic finding of the model was, if there's enough air to cause drag, there's enough air to use to make thrust to counter it, and enough air to produce some lift.  You can make ro v^2 work for you as well as against you.  Since then, I've worked on MarsFlier, which is capable of generating lift at subsonic true airspeeds and above 100 k ft, so I tend to believe the principle.

I won't claim the model was totally rigorous, but I convinced myself that such a craft could be made to work given sufficient electrical power in a compact enough package.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/14/2007 04:34 AM
Too ambitious a scale up insures it will not work.

I speak as some one involved with understanding the issues involved in high power nuclear reactors (500MWth and up).

It is sad that Dr. Bussard may not live to see the first high power system operational. Life isn't always fair.

It took from 1942 to  1953 to get the first nuke submarine reactor operational with a similar scaling to what I proposed.

After WB7 and WB8 the next two or three test reactors should be fast to construct and test. That gets you to 100KW.

A jump to 1 MW would be the first serious engineering hurdle. You might go from there to 100 MW although an intermediate step of 10MW might ease the engineering.

Dr. Bussard probably outshines us all in plasma physics. When it comes to what investors (other than the government) might risk he is not too savy.

At each step the next step must be relatively low risk.

Think of just the added heat load in the case of collector efficiencies between 70% and 95%. Suppose the total output of the system (including losses) is 100 MW. You are then talking about  a thermal load of between 5 MW and 30 MW. That is a HUGE risk. You have to know the efficiency within a few percent of total reactor power to have a chance at designing a working system that has a final power output within 10% of design.

A lot of this could be determined with short runs of D-D while p-B11 reactors are one order of magnitude behind the D-D reactors.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/14/2007 06:17 AM
From an investor stand point the worst thing that could be done is to promise a 100 MW output and only be able to deliver 10MW.

That immediately brands the unit as a failure.

Better to make the mistakes at low output where the costs are lower.  

Scientists can afford to be adventurous. Engineers are not so lucky.

A 1W - 100KW - 100MW progression is possible at high risk. No way I'm going to skip the 100KW test. Just enough power to look into second and third order effects. Not enough so that fixes are very expensive. I'd still prefer 1 MW and 10 MW tests. BTW do you know what it costs to keep He4 cooled to 4 deg C in a vacuum? Not to mention pumping rqmts.  Now try doing that with 15MW to dissipate from your collector grid at 350 deg C.  radiating in a vacuum charged to 2 1/2 million volts near to your superconducting coils. Not to mention 200,000 volts in the grid surrounding the superconducting coils. Suppose you have to pull 1 MW out of that grid?  Tricky.

Then all the plumbing - leak tight  to better than .1 torr total  with the available pumping for all the joints bolted and welded.  All electrically isolated from grid voltages.

The very best thing Dr. Bussard could do is to explain what he has done well enough so that 100 smart people could understand it as well as he does. Then his work will live on. Right now I see the situation as tenuous.  If he dies before writing up his experiments it will set IEC Fusion back 10 to 20 years.

Oh yeah.  Power conversion will be the last thing done so you will need a resistor bank capable of about 100 MW dissipation at 3 million volts and 50 Amps. The resistance variable in small steps. 100,000 ohms nominal at 100 MW variable between ten million ohms  at 1 MW  and 10,000 ohms at 10 MW.  That is not going to be cheap. Or you might opt for a 100 MW 3 million volt DC to AC converter and use water doped with sulfuric acid as a water cooled load with the appropriate water towers. If you can raise and lower the electrodes going into the sulfuric acid bath you can make a high power variable resistor. This will not be cheap.

The initial high power model should be the minimum power (plus margin for design error) that the electric companies will accept as a regular power provider dispatched by the grid controllers. Something in the 2 to 10 MW range I believe. You want to do what Edison did with his light bulbs. Turn them on and see how long they will run as a grid provider. Profit is not the initial motivation. Proof that you can be reliable is a definite requirement for further scale ups.

Another thing the 2 to 10 MW range buys you is off the shelf cooling towers, small natural gas fired boilers to test your thermal eqpt under load.  The 3 MV DC to AC converter will be custom.  However, its cost could be quite low because you could use very low cost transistors with very modest cooling requirements for the control string.  One amp at three million volts is 3 MW.  If you used 1200 volt transistors derated to 600 volts. You would need  5,000 transistors. If they cost $3 each that would mean $15,000 for semiconductors. Cheap for a 3 million watt converter. The hard part would be isolating the firing circuits from the 3 million volts and getting all the units to fire "simultaneously".  What you want to do is to used the lowest R on FETS  in the largest possible package and air cool them.  If you size all that for 60 Watts dissipation per transistor that allows for 300KW of dissipation making the unit 90% efficient. Do able. With a MTBF of 1 Million hours that would be 1 transistor failure  every 200 hours. If it required 500 transistor failures to refurbish the machine That would be 1 year continuous running between overhauls. If you could rack up similar numbers  for the reactor (meaning a good probability of operation 6 months between repairs) that would be excellent (to start).
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/14/2007 07:48 AM
I don't understand why the reactor has to be so big.  Is it just the coil thickness that's needed to carry the current to generate sufficient magnetic field strength?  Well, once they are superconducting they could be made any size, right?

More progress could be made miniaturizing everything in WB7 and WB8 so that a demo reactor can be built and fit in the palm of your hand.  I really don't understand why things have to be so big.  Like ITER, huge man!

What is the size-limiting condition?  Protons are pretty small.  I can't imagine why a reactor has to be exactly 3 meters in radius to fuse a tiny proton to a tiny boron ion.  Why not 3 miles?  Why not 3 centimeters?  It seems like an odd coincidence that the demo reactor would be just the right size to fit in a laboratory run by 10 people.  There is something suspiciously arbitrary about it.  Is it just because nobody wants to use tweezers to build these things that they have to be so big?  Maybe Bussard should hire an atomic force microscopist.  I hear they are using cantilever devices to assemble things using molecules.  That kind of expertise could be put to good use.

After WB7 & 8 are proven, I would suggest WB9, WB10, WB11... and so on, each proving greater and greater feats of miniaturization, reducing the size of the ultimate reactor that achieve net power.  If some day a power-producing fusion reactor can be etched on a silicon wafer, that would be an extraordinary day indeed.

In fact it would be a revolution.  Imagine appliances fueled by water.  The built-in reactor kick-started by a spark of electricity when the ON button is pushed.  With just a little help to get started, the reactor power-up to maximum on it's own using a feedback cycle, electrolyzing water to obtain hydrogen and using electrophoresis to extract boron-11.  Within milliseconds the appliance is running, boiling water, lighting the room, connecting to the internet, etc.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/14/2007 01:04 PM
Tom,

I would really like to see this work... Trust me....

Now, I have some knowledge of physics, but I'm no aero engineer so some of my concepts may be a little fuzzy.

As I pointed out in an earlier post, until your getting real close to orbital velocity, the net gravitational acceleration towards the ground isn't much lower than at rest velocity.

Note: While going over the numbers I posted earlier, I think I had an error in my numbers a few posts back.

The formula is

Gf    = Gravitational Force towards the ground (1 Gf = 9.8 m/sec^2)
Vorb = Orbital Velocity
V      = Current Velocity
G      = Gravity while at rest on the ground

 Gf =   ( 1 - ( ( V / Vorb  ) ^ 2 ) )  * G

At 50% of orbital velocity your at 75% Gf
At 75% of orbital velocity your at 44% Gf
At 90% of oribtal velocity your at 19% Gf

With a low thrust engine, your depending on aerodynamic lift to counter that gravitational acceleration
until your nearly to orbital velocity.  You may have to stay lower in the atmosphere to get that lift than you were planning.  And because of that, the drag would be a lot higher than anticipated.

Now the other problem.  We are discussing lift, drag, and thrust.  Yes, you've got a high power fusion reactor generating a tremendous amount of energy.  Most of that energy is going into overcoming
drag, a smaller amount of that energy is going into accerating your vehicle.  Your going to get a tremendous heat load.  Travelling 3/4 of the way around the globe in the atmosphere at near orbital
velocity is going to generate a tremendous amount of heat.  Much more than even Apollo experienced returning from the moon.

Now that is "just" an engineering difficulty, but that is one of the reasons why I'm looking at the higher thrust road.

As for the post about JP aerospace.... I wish them luck, but, I'll put that one in the catagory of cold fusion.  Great if it can be made to happen, I just don't see it being possible for the same reasons mentioned above.  Which is why I have difficulty with the low thrust fusion engine going to orbit.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/14/2007 09:00 PM
There's no technical information available on Bussard's work.  There is just one paper, but it's not well written, and doesn't provide any insight into the physics, or why the reactor is designed the way it is.  His website has no technical papers, no diagrams, emails are not responded to.  And there is every expectation that the net power reactor will be as big as ITER.  Even if it produces net power, the reactors will be so big and expensive nobody will build them.  Those that do will take decades of construction to complete.  I'm kindof tired of waiting for results, and Bussard isn't helping the situation.

For now I'm going to throw my support behind ligher-than-air wind turbines, such as by Magenn Inc. of Canada.  They're doing some good things there.  Easy to understand, easy to implement, and easy to support.  Anyone who looks at a lighter-than-air wind turbine knows it's going to work.
Title: Re: Fusion with space related aspects thread
Post by: mong' on 04/14/2007 09:16 PM
although it might look funny on a spacecraft...
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/14/2007 09:18 PM
Quote
SemperUbiSububi - 14/4/2007  3:00 PM
For now I'm going to throw my support behind ligher-than-air wind turbines, such as by Magenn Inc. of Canada.  They're doing some good things there.  Easy to understand, easy to implement, and easy to support.  Anyone who looks at a lighter-than-air wind turbine knows it's going to work.

It's a drag device.  It might work but it will be horribly inefficient.  I'd guess the Cp on that thing will be less than 0.05 (modern turbines are usually around 0.48).

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/14/2007 10:18 PM
The size constraint on these things has to do, at least in large part, with the fact that you can't just pick any old density and expect to get a net power reactor.  Too high a density results in excess non-fusion collisions and you just get a Maxwellianized plasma.  Too low a density results in too low a power density.  There is a definite envelope in which the best power output is possible.

Couple that with expected R^7 scaling and you get the required size for a net power reactor.  The equations have been aiming at that size for at least a decade and a half.  The difficulty was trying achieve the electron confinement theory said should be possible.  There is some latitude in the design to go a bit smaller due to the fact that the scaling is actually B^4R^3, but you can't do it all with magnetic field.  Volume is necessary.  Higher B field does make the machine reach net power at a smaller size.

The reason Dr. Bussard wants to just aim straight for net power is that the R^7 scaling is so incredibly steep, it seems to be a target you just can't miss, like aiming for the side of a barn at close range.

The size, mass, and cost of the thing is way below ITER.

I am fully expecting investors to want to explore at least one intermediate size, but I also understand Dr. Bussard's desire to go straight for net power.
Title: Re: Fusion with space related aspects thread
Post by: meiza on 04/14/2007 10:19 PM
why not an autogyro turbine?
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/14/2007 10:32 PM
Quote
meiza - 14/4/2007  4:19 PM

why not an autogyro turbine?

Because it won't fly to the altitude they think it will.  The drag and weight of the wire is the problem.  Just look up the world  altitude record for a very advanced kite (no generators, no electrical conductors, no inefficient rotors, no controls, etc.) and compare that to the wild claims of these little garage inventors.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/15/2007 08:51 AM
There is no doubt that with the right size reactor you can get net power of 100 MW.

If you are too far off from your thermal estimates you won't be doing it for very long.

Think of it this way. You want to go from bottle rockets to a Space Suttle in one step. Even given that the technology is out there, it is still rough.

In any case it will be what it will be.  If Dr. Bussard can get some one to enlarge the reactor by a factor of 10 and increase thermal loads by a factor of 1E7 in one step - go for it.

All I can do is state my perspective as if I was an engineer for a venture capitalist and had to design a program incorporating a series of intermediate steps to validate the engineering. Due diligence.  Even if it would cost more, people with money want to be able to cut their losses when you can't advance the technology even if it means taking a hit in profitability.

It is all about managing risk.

You always need more than one plan. And plans get revised.

Did I mention that you want to scale up in that one step from pulsed operation to continuous operation. That is a lot of ifs to swollow.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/15/2007 10:38 AM
I don't believe for a second that a demo reactor is going to be built.  The only reason Bussard threw the idea of a net power reactor out there is so people have a fantasy to latch onto.  It's the same reason he keeps selling to idea to space enthusiasts, it's just a fantasy.  Dreamers lap it up.

The DOE won't fund his work.
The DoD cut off his funding.
His own reactor blew itself apart.
He hasn't published anything.
His website has no information.
He doesn't respond to e-mails.
He won't talk to government research organizations.
He's approaching private sector without first building a net power prototype.
He is relying on a non-profit organization to collect donations.
He is relying on a volunteer for public relations.
He refuses to believe there are people in this world that are smarter than him and able to understand his work.
He has no credibility.


This is about Bussard remaining in control of the project.  Knowledge is power, so he has simply prevented anyone, and I mean anyone, from gaining comprehensive understanding of his polywell reactor.  Not that it is difficult to understand in concept, but for some reason he's spent 10 years or more without generating any meaningful documentation.  No wonder they shut him down.  Most university researchers by his age have written two or three textbooks, and then some.  He even stated during his Google lecture that he previously and knowingly committed fraud by advocating tokamaks.  How do we know he isn't doing the same thing now?  Are we supposed to take the word of Tom Ligon on this issue, some guy who's not even involved in the work?

Usually the cranks are easy to pick out:  free energy, cold fusion, perpetual motion machines and their ilk.  It's difficult to figure out why educated people with full credentials would try to pull one over on the general public.  Bussard has already made a name for himself, why ruin it with a stupid scam?  If I wanted to pay money for a novelty device that glows when you plug it in, I'd go buy a Plasma Lamp.  At least it looks good, and doesn't raise expectations by promising 'net power production'.  They make money too for the businesses that sell them.
Title: Re: Fusion with space related aspects thread
Post by: braddock on 04/15/2007 11:20 AM
Bussard does have a draft paper circulating, the "Valencia paper" submitted to the 57th Annual Astronautical Congress in Valencia, Spain, last October.

Here is the draft of "The Advent of Clean Nuclear Fusion: Superperformance Space Power and Propulsion":
http://www.askmar.com/ConferenceNotes/2006-9%20IAC%20Paper.pdf

Tom, was this paper accepted?
It seems to me a strange venue for a revolutionary nuclear physics paper.  I am not a physicist, but the paper itself does not seem particularly rigorous.

Semper, as for your complaint that he researched for 10 years without generating any meaningful documentation: the above paper references fourteen separate EMC2 technical reports presumably written for the Navy sponsors.

Your other concerns do worry me though.  Are there other physicists involved with EMC2 who are willing to defend or inherit his work?  Are there any business relations people working with Bussard who can aid in his presentation problems - like this ill-defined and poorly presented non-profit attempt?  Benson should be able to loan him a good MBA intern who could do a better job of the latter -- and if any other physicist worked at EMC2 those years, he should be begging to associate himself with the success.

It is impossible to know what is going on behind the scenes, of course.  Maybe Bussard has already pounded out a deal, and doesn't care about public perceptions, or is working hard on peer reviewed validation now.  But as the clock ticks and these things don't emerge, it certainly doesn't look good.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/15/2007 04:36 PM
Braddock,

To understand why this would be presented at a space development conference is to understand Dr. Bussard's life.  It is all about space, and always has been all about space.  The dream of human exploitation of space has been his primary motivation since early childhood.  While he certainly fully appreciates the terrestrial applications of the technology, and the changes it would bring, he has never taken his eye off the goal of applying this to space transportation.

The Valencia report was never intended to be a rigorous peer-reviewed research paper in the sense of mainstream research.  It was simply a summary report of a large body of work.  I believe this was published in the proceedings of the conference, but Dr. Bussard was unable to actually present it due to health issues.  The Valencia paper represents a substantial information dump ... I've spent days delving into it and still find something new every time I look into it, and I am already familiar with the subject.  For someone who thinks they know something about plasma physics and fusion, I'd say they would have to study the Valencia report for weeks before they started to fully grasp all that is in it.  Once a person could fully appreciate this report, they would be in a position to appreciate a series of peer-review-suitable papers on the various technical aspects of this approach to fusion.  

It is not uncommon at space conferences to have a number of presentations that are not intended to be for peer review.  My talk at ISDC certainly will not be for peer review.

There have been a number of papers published on this research in the path that were quite rigorous, and you will find them in the references of the report.  But the early papers are very easy to overlook.  "Well, look, Bussard and Krall have some very interesting math here ... I recognize the starting equations ... algebra looks correct ... well, I'd love to see if they could actually make this work."  

The Valencia paper says they got it to work.

Yes, the Valencia paper is rough around the edges ... It shows all the usual earmarks of Dr. Bussard working solo, with no assistance from a secretary and somebody to generate pretty artwork.  And picture trying to write such a report, by yourself, on a deadline, with the distraction of a serious illness.  One of the first goals of the NPO is to get him some office help and some young physicists to help produce more polished and presentable papers.

I understand Semper's skepticism.  Fusion claims have failed to produce so many times in the past that the gut reaction is warranted.  But WB6 really did produce those four bursts of neutrons, and they really are highly significant.  I understand them.  I know they mean the device basically does what it is supposed to, and that the scale-up ought to work.  It would be absolutely tragic if we let this approach die due to the sort of "logic" Semper applies.  Just as it would be silly to start building p-B11 spacecraft without getting that net power demo plant running.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/15/2007 04:49 PM
Semper,

The reason Dr. Bussard did not publish anything on the reactor theory or results for 11 years has nothing to do with his personal desires to keep anyone from knowing about it.  The reason was the sponsor absolutely required that he publish nothing.  That, in turn, had to do with some internal politics in the organization providing the funding:  the DOD.

This project has had various types of government funding over the years.  Thus far, every one of them has failed to follow thru at some critical juncture.  The reason for going for private money at this point has more to do with seeking someone who actually has some vision for the future.

Would I be more credible as a cheerleader if I were being paid for it?

I appreciate your skepticism, but please re-examine that list you present up above and ask yourself if you are willing to jeapoardize the entire future of the human race on such "proofs".

You object to the NPO ... but for folks like us to fund the NPO will allow him to get out the papers we all (me included) so eagerly want to see.  And they will allow it to happen without the censorship the last funding source, our own govenment, imposed.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/15/2007 05:01 PM
MSimon,

Actually, one of the goals of the WB7/WB8 project is to get the reaction going for far longer times, well beyond pulsed.  I think it will be possible to run the magnets for seconds or tens of seconds even in those small devices, and the reaction can then run a substantial fraction of the magnet run time.  

There is nothing about the reaction that inherently relies on pulsed operation.  The intent has always been continuous operation, with Dr. Bussard always expressing very strong reservations about using pulsed test methods.  He would not have gone that route if he had any other choice, and the reason had to do with available building power and the equipment on-hand to run the test.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/15/2007 05:25 PM
Quote
Tom Ligon - 15/4/2007  10:36 AM
I understand Semper's skepticism.  Fusion claims have failed to produce so many times in the past that the gut reaction is warranted.  But WB6 really did produce those four bursts of neutrons, and they really are highly significant.  I understand them.  I know they mean the device basically does what it is supposed to, and that the scale-up ought to work...

The claim is that the physics is at least partially understood at this point and that all that remains is engineering.  But I'm still wondering about the thermodynamics of the system if it actually does produce continuous fusion at a large power level.  Has anyone taken a look at that from a back-of-the-envelope perspective?  Given the heat flux expected and the available surface area of the magnets, it should be simple to calculate whether you need simple water cooling, phase-change cooling, or some unattainable approach.

It looks to me like you have on the order of 1000W/cm^2 to get rid of from the magnets, but I admit that this isn't even a back-of-the-envelope calculation (more like a WAG) as I don't really understand where the losses are or the dimensions over which they are imparted.  But you (the collective you) should be able to at least get into the right order of magnitude on the assumption that fusion is taking place at the rates you think will happen.  This number would allow you to determine if the approach is even feasible thermodynamically - and that counts as physics too, you know.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/15/2007 07:38 PM
Tom,

The problem with pulsed operation is the difficulty of accurate thermal balances. You want to get as steady state as possible to get the thermal balances right.

There will be errors enough in scaling without also having to deal with errors in your rate of change equations.

There really needs to be one or more intermediate steps in the ENGINEERING. You have no idea how the sudden appearance of an unexpected MW or three can ruin your day. Nuke reactors could take large scaling jumps because the whole reactor was in contact with the cooling medium. Nor so with a reactor operating in vacuum conditions. You forget to cool something important or provide inadequate cooling to an important part of the apparatus and you have a dud.

Scaling up anything by 1E7 in one jump is incredibly risky. Unmanageably risky. It smacks of charlatinism.

You know it is possible that if, despite  the Drs advanced years and poor health, he was not in such a hurry he would go faster.

Which headline would you rather see?

FUSION REACTOR FAILS TO ACHIEVE PLANNED OUTPUT

FUSION REACTOR ACHIEVES PLANNED OUTPUT

FUSION REACTOR EXCEEDS PLANNED OUTPUT

FUSION REACTOR EXCEEDS PLANNED OUTPUT AND OPERATIONAL TIME

Which is why modest plans are best. You want to be near the edge of what you know. Not far beyond it.

Once you ask for money the whole project leaves science and becomes a psycho-social problem. Along with all the technical problems. Most scientific people do not get the psychosocial dimension. Which is why science and engineering are different disciplines.

Here is an example from my own career.

I was called in (as a contractor) to manage the engineering on the display portiion of a lap top. There were three guys in the seat before me in the previous 6 months. None of them had the guts to sign off on a million dollar contract for the liquid crystal screens. I checked with all the relevant people and when I was reasonably sure of the situation I signed the contract. (to the great relief of the Toshiba folks who had been trying to get the contract signed for months so they could allocate resources for production). Too much fear. However, too much optimism is just as big a problem.

A good development engineer will be moderately reckless.

I would call an engineering jump from  1W to 100MW exceedingly reckless.  A 1% error in your loss budged and you have a MW to deal with. On your 1 W job you will be lucky to get the loss budget for your 100 MW unit to within 5% of total output.  A scaling (given well known scaling laws) by a factor of 10 is considered risky. A factor of 2 is where most advances are made.

My ideal progression:

1W  - 100W - 10KW - 1MW - 100MW  

Which would represent size doublings (roughly).

Follow on to the 5 year program: - 300MW and  1,000 MW.

Then it is rocket time.

If you planned on that as part of the 5 year development program I think it could be done without taking much of a time hit. If it was planned. If it gets forced on you chaos develops. There will be more than enough unknowns at each step. Look at what the tokamak guys have gone through. It is unlikey that the Bussard Reactor is exempt from Murphy's Law.  The DC to AC converters alone will be a severe engineering problem. The voltages involved will be about 3X the highest currently done in the MW range. Think about it. For testing you want a 1 MW 3.5 MV max. 1 A max variable  DC power supply.  Feeding you 2.8 MV DC at  .4A (1 MW nominal) converter. The testing has to be done when kicking the load suddenly off line (failure) will not seriously affect the distribution system.

In any case it is always possible to delete steps from a plan if things go better than expected. It is hard to add stuff when things go seriously wrong.

So you need a reactor group. A thermal group. An electrical group (power and control). And a support group consisting of mathematicians, metalurgists, electronic design, etc.  and administrative support - purchacing, contracts, etc.

The reactor group alone is going to have to have subgroups: electron guns, fuel injection, vacuum group, magnetics group, collection grid group, plasma physics. Possibly others - all working with the thermal group. Plus you want to have some mathemeticians on staff for helping the engineers with the hard stuff. Reduce the engineering to algebra/trig or computer programs with graphical and table outputs.

Then you have to have some one who can ride heard on this collection of prima donnas. If they aren't prima donnas I don't want them on the program. Think Manhattan Project. Or Rickover re: nuke subs. We want very smart experienced people with an excess of confidence. With a pessimist riding herd.

I think it took the Naval reactor group from 1948 to 1953 to get delivery of the sub reactor prototype. With 6 years prior experience in low power and low power density reactors.

=====

Murphy is like a wizard: subtle and quick to anger.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/15/2007 08:34 PM
MSimon,

Actually, I'm not really in disagreement with you personally.  I'm trying to represent Dr. Bussard's side of the argument.

If it were my program, I'd probably argue for doing just about what you suggest due to my inherent cowardice.  And whoever finally funds this is very likely to insist on it.

As for haste-makes-waste, maybe one day I'll be able to write the whole long, sad story.  In retrospect, there are several key spots where asking and answering the right questions might mean we'd now be picking destinations for the resulting spacecraft.  The earliest of these is circa 1968 when a bunch of AEC guys attended a meeting with Hirsch and Farnsworth.  H&F rigged up a fusor on a borrowed meal cart from their hotel, and rolled a working fusion reactor into the meeting, where they irradiated the attendees with a fairly substantial flux of neutrons, to their amazement and delight.  That little machine was making more controlled fusion than had ever been achieved at that time by any other means.  Everyone present thought IEC was worth pursuing.  However, nobody wanted it taken out of their budget! So AEC and later DOE never pursued it (even after Hirsch wound up in charge of the henhouse at the DOE fusion program a few years later).  By the 1970's, the system was so hidebound there was no way to squeeze in an electrostatic approach in competition with lasers and tokamaks.

In the 1980's, the HEPS experiment used the closed-box Polywell configuration instead of a MaGrid, and was run pulsed (against Dr. Bussard's objections).  Had the MaGrid concept's advantages been fully appreciated at that point, that machine had sufficient resources behind it that the effort probably would have put us in the 1980's where WB6 is now.

WB2, 3, and 4 were all built with square crossection coils, touching each other.  These two subtle form factor problems caused much larger electron losses than had been realized.  They were economy measures (made the coils much easier to build) that wound up keeping the devices from working, so they were false economy.   Had WB2 been built in the form factor of WB6, and with somewhat more robust magnets, I suspect it might have been able to burn DT at detectable levels.  WB3 likely could have made decent fusion on DD, and would have done so for 10 seconds at a time.


Title: Re: Fusion with space related aspects thread
Post by: jstrout on 04/15/2007 08:52 PM
Quote
SemperUbiSububi - 14/4/2007  3:00 PM

There's no technical information available on Bussard's work.  There is just one paper, but it's not well written, and doesn't provide any insight into the physics, or why the reactor is designed the way it is.  His website has no technical papers, no diagrams, emails are not responded to.
I think you just haven't looked hard enough — the early work (before the publishing embargo) is described in several peer-reviewed papers published in Fusion Technology and Physics of Plasmas.  See references 1-3 at http://www.strout.net/info/science/polywell/index.html .

You do need to study the new paper plus the Google lecture a bit to see what's changed since then, but I think it basically amounts to: they've figured out how to minimize the electron losses by allowing them to recirculate in an open-box machine.  So as you read the older papers, just keep in mind that the problem of electrons colliding with the hardware has been essentially solved.

Quote
And there is every expectation that the net power reactor will be as big as ITER.
I don't know where you get that expectation.  Bussard has calculated that the net power reactor will be about 3 meters across.  You easily put one on a Navy ship, not to mention power a city with it.

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/15/2007 10:58 PM
I don't believe that.  Maybe the magnetic bottle will be 3 meters in radius.  That's 6 meters (20 feet) in diameter.  That's huge.  The ITER coils are about 9 meters (30 feet) wide.  It's bigger but not by an order of magnitude.  The total system that Bussard is suggesting, vacuum chamber, plumbing and everything else could well be comparable to the size of ITER.

If he can't reduce the size, then he should look for ways to reduce the cost by a factor of 100.  If anything would impress the private sector, that would.  I seriously doubt the private sector is going to come up with $300 million.  Even the X-Prize was only $20 million, and Scaled Composites needed a billionaire to donate the money.  Bussard wants 15-times that much?!  Good luck with that.

A billionaire might donate $2 million.  But I imagine there would have to be an emphasis on long-term philanthropy and/or business.  The latter would push for cost reductions.  Ruthless cost reductions.

Ultimately the problem here is that Bussard isn't going through proper channels.  Due process is important.  If he believes that the process is too slow and he will die before achieving anything that way, then publishing should be his first priority.  Educating and training people in the physical principles of his design will ensure that someone can carry on his work.  An undergrad, grad, and post-grad university textbook series would ensure a sufficient trail of bread-crumbs that new people can gain the knowledge necessary.  Publishing in peer-reviewed journals should be secondary, because IMO they aren't so polished as people are led to believe.  Duplicating work based on a few journal articles is often virtually impossible, due to errors and omissions, and the huge number of references to pior work.  It is difficult to make sense of, to calibrate equipment in the exact same manner, so to verify that claims are true.  He should go with a textbook series.  Now those are polished, high quality publications.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/16/2007 01:36 AM
Semper,

There's considerable merit in your textbook comments.  As Dr. Bussard, in partnership with R. D. DeLauer, literally "wrote the book" on nuclear rocket propulsion (they collaborated on two textbooks on the subject), he may well do exactly that.

He has commented that nobody is going to understand this technology based on one paper.  He feels that it would require several semesters of graduate study.

You and I think $200 M is a large amount of money.  It is not trivial in anybody's book.  It is not really large or un-doable for US business, be it a single billionare or a group of venture capitalists.  Such people rarely sling money around carelessly ... if they invest that kind of money without due diligence, they probably won't be venture capitalists for long.  But, if they have the vision and understand the risks, the energy this technology could produce would be worth some trillions a year, and the initial investment is chump change.  If business sees a favorable risk/reward payoff, the money can be raised easily.

There are yachts and homes out there worth more than $200 M.  I live in a smallish subdivision worth around that much.

The US government spends that much in about 16 hours in Iraq.

Tom
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/16/2007 01:58 AM
I thought it was a roughly 3 meter cube.  That would fit in my living room.  It would also fit easily into a 5 meter diameter vacuum chamber.  Los Angeles class submarines are 10 meters in diameter.  In other words, it's not all that big.  The ITER, is in the neighborhood of 10 meters in vertical cross section and 16 meters in diameter, IIRC.

I don't know if the thing works or not, but the sizes proposed are not nearly the size of Tokamaks.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/16/2007 04:34 AM
I understand Dr. Bussards experimental limitations.

My point is/was that it is very hard to do steady state thermal work based on pulsed operation. It has to operate long enough to get to or very near thermal equilibrium.

Without good numbers on thermal loads scaling up by a factor of 1E7 or 1E8  in power is going to be very very risky.

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/16/2007 05:07 AM
Publishing articles in journals will ensure that his work remains in permanent obscurity.  I can't tell you how many times I've gone into a university library and just gotten lost in the literally millions of journal articles on any given subject.  It takes hours to just find a dozen relevant articles, and maybe one or two that are understandable.  Most are useless, too specific, too technical, too many references to other articles.  And how long would it take to find all the articles listed in that article's footnotes and references, and all the articles listed in their references?  Too long, believe me.

In contrast a textbook would be comprehensive.  A few volumes of maybe 2000 pages each could contain the sum total of his work, properly organized in a sequential fashion, with a table of contents, an index, formulas, explanations, and loads of diagrams.  Textbooks also have in-chapter examples of how formulas are used to solve specific problems, and more end-of-chapter problems for students to solve.  Textbooks are also being sold these days in PDF format so people can carry their education around with them on their laptop computer, print off a few pages if needed, or look something up quickly without carrying around a 20-pound hardcover volume.  You can't say the same thing about journal articles.  At best you might be able to access the abstract if you have an internet connection.  That's not very helpful.

Where journal articles are filed away and forgotten, textbooks are used to teach millions.  Students also keep textbooks as personal references on their shelves for the rest of their lives.  They are never forgotten.  They are used over and over.  Their presence on a bookshelf together with a paper degree or diploma hanging on the wall prove that a person is QUALIFIED.  Journal articles do nothing.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/16/2007 05:09 AM
There is a lot of off the shelf eqpt out there for use in the 1 to 5 MW thermal range. When you get up to 100 MW you either have to have access to the Idaho Reactor Test Facility or design your own.

A 1 to 3 MW, 3 MV DC to AC converter could be done (including engineering) for around $ 1/2 million.  For 100 MW it is going to cost a whole lot more.

Reactor scaling is not the problem. The problem is in the cost of the auxiliary eqpt and the risks in acquiring it. Stuff you can resell on the open market vs custom is lower risk. In fact costs could be kept in check by buying as much as possible used.

Suppose your 1 MW job requires 2 MW to run it  (because of losses).  You buy an electrical contract for 30 days at $5K  per day ($200 a MW hour) and run it feeding the grid for 30 days. Electrical cost $150K.  At that point getting additional money is NO PROBLEM.

Maybe you might want to think about a $2 mil, $20 mil, $200 mil program. Think of it as science proof, technology proof, power generation.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/16/2007 03:28 PM
MSimon,

I suspect the proposed net power reactor will be intended to demonstrate only that the nuclear reaction can run at that power.  I doubt the device would be designed to actually produce electrical power at that level.  Possibly it would simply run in a hole in the ground with sufficient devices around it to measure the reaction rate, likely as raw heat.

At that point, you've demonstrated the reactor runs, and there will be no stopping the technology.  But that's also, quite obviously, where the really serious engineering work begins.  Demonstrating net power from the fusion reaction itself is THE key risk-reduction step that makes it possible to begin seriously planning power reactors.

Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/16/2007 05:39 PM
Wow,  walk away from a topic for a day and there are a huge number of posts.  This is good to see.
I'll have to read them and digest them completely.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/16/2007 07:15 PM
Tom - most investors are not interested in a $200 million science fair projects.

Which is why you have to have a working system that actually delivers power. Even if your scaling laws prevent net power generation.

At the point of building the power reactor you have two points on the scaling curve. Extrapolation to power generation  then is not unreasonable.

Dr. Bussard claims that he is nearly ready for the engineers. He ought to hire one or two with actual industrial experience in power generation. Because, engineers think differently than scientists do.

Skipping steps in the "science proof, technology proof, power generation" sequence is unwise  if you want investment money. Governments are not as scrupulous.

Title: Re: Fusion with space related aspects thread
Post by: Tergenev on 04/16/2007 07:25 PM
M Simon -

Engineers think differently than all other human beings. And that difference ain't always better, either.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/16/2007 07:42 PM
Engineers think differently than all other human beings. And that difference ain't always better, either. -Tergenev

I suppose it depends on whether you want to build experimental bridges or passenger carrying bridges.

If you are asking for gobs of investor money passenger carrying bridges are the prefered route.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/16/2007 09:45 PM
Something you may not realize about R. W. Bussard, is he actually IS an engineer!  His first degree was thermal engineering.  He specifically studied that field in order to figure out how to utilize the heat from a nuclear reactor to make a rocket engine.  The Rover program, and hence NERVA, was the result.  If there is one thing he knows on an engineer's level, it is how to extract heat from a nuclear reactor on an industrial scale.

Only after getting that running did he go to Princeton for his PhD in Physics.  

You guys have been objecting at the idea of going straight to net power without some technology demonstration in between.  But now I see you calling for not hitting net power unless the reactor is ready to drop into the power grid?!!

We know how, given a heat source, to make steam and turn turbines.  We can figure out how to take a flux of charged particles and get power out of them (even if we have to resort to making steam as an intermediate step).  The high risk step is demonstrating that, for the first time in decades of trying, we can make controlled fusion at net power levels.  Demonstrate that, and powerplants will be feasible, one way or another.  But if that can't be done, the power conversion technology is irrelevant.

That's why Dr. Bussard wants to demonstrate net power.  That's the thing that has never been done.  That's the thing that proves it is worth the investment to move on to commercial powerplants, and will make it possible to estimate the investment required to do that.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/16/2007 10:59 PM
According to Dr. Bussard, in the Valencia paper, the physics are proven.

From what I've seen he is very likely to be correct.

Given that, all that is left is engineering.

Now the problem is convincing the venture capitalists that that is the case.  Once that point is reached,
the money will pour in.  I think that the purpose of WB-7 and WB-8 are just to prove to the world that the
physics problem is indeed solved.  And WB-7 and WB-8 are cheap.  Really cheap.  Under $3 Million.

The next step after WB-7 and WB-8 would be a full size prototype reactor.  It probably won't be able to produce economical power.  It may not be able to power itself, but that would be why its a prototype.

From that reactor, we should be able to learn enough to produce an economical power plant.  And each
generation of reactor after that should be more efficient than the one before it.

If the physics is basically correct....
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/16/2007 11:39 PM
Such discussions as we are having here are why you make up multiple business plans.

Net power generation is not near as important as proving the scaling laws and showing the collector grid idea works. Right now the collector grid and other thermal loads are probably the biggest unknowns. Other than understanding the reactor physics.

It is a lot cheaper to learn that stuff at 1 MW than at 100 MW. Buy and bolt vs design, buy, build, bolt.

So far the highest voltage to ground inverter that has been built is 600 KV. So a scaling by a factor of 5 in voltage insullating capacity is required. It also means 2.5 times as many semiconductors (considering +/- 600 KV to ground.

Here is a bit on a HV DC (+/- 533 KV) line:

Cabora-Bassa.

Valve Hall.

*
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/17/2007 12:08 AM
Are the thermal loads unknown?  Only to the extent that net power has not been demonstrated.  If you suppose a star of fusion plasma running at 100 MW exists in the middle of the reactor, the actual thermal load on the reactor elements should be pretty straightforward: hellish.  And if this condition can't be achieved, then THAT is a problem, because its pretty much the whole point of the device.  The specific engineering details for dealing with the thermal load is an unknown at this point, but it is putting the cart before the horse.   I'd put the most critical part of that as dealing with heat losses due to fusion products hitting the MaGrid, and the issue clearly will be to intercept that energy well before it gets down to the level of the superconductors.  If you boil water with it, you have a jacket at a thousand kelvins or so to insulate (with a vacuum gap) from and underlying LN2 jacket, a vast improvement over incandescent metal.  

At present, it is neither the physics nor the engineering that is the hang-up.  It is the business. As has rightly been pointed out, at the moment the project really hangs on obtaining funds.

Typically, venture capitalists have no problem raising billions of dollars, if they can point out, say, 2-5 years in the future and say, with reasonable certainty, that the project will show a return on investment of such-and-such.

The fact that Dr. Bussard is so confident net power can be achieved is why he felt he could finally approach the private sector.  This does not guarantee the private sector feels the same.

I don't know the present state of funding, but my gut tells me that somebody will scare up a few million bucks to fund the WB7/8 effort.  Success on that would stir up interest.

The scale of the next effort after that will depend more on the risk tolerance and confidence of the people providing the funds.  If they want to go mid-scale, that's just what will happen.  If they want the net power attempt to boil water and make steam, that's what they will do.  But if they're looking to get in on the ground floor, and "own" the core technology, and have confidence in the correctness of the approach, their quickest return on investment may be to just fund the net-power demo and build it by the quickest means.

I firmly believe that a net power reactor will make the future of the technology so clear that you quickly find a flood of people wanting to exploit the basic ability to make net power.  That's when the mainstream VC types start waving billions around.

Billions ... is that a lot?  What's the cost of a luxury hotel or cruise ship?  Not a problem for businessmen who can see a clear profit ranging in the hundreds of billions to trillions a year.

At this point, both physics and engineering take a back seat to economics ... what does it take to attract the people with the money?   Gee, I wish I had some money, then maybe I could tell you the answer.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 12:45 AM
Tom,

The "get in on the ground floor" mentality reeks of charlatinism.

Yes loading on the Magnetically Shielded Grid is going to be tough.

Just as tough will be the collector grid since you have no firm basis for any efficiency factor between 70 and 95%. At 100 MW that is a range of 5 to 30MW for cooling.  With a 1 MW reactor the range would be 50KW to 300 KW. So you get a 1 MW cooler and forget about it. Adjust the flows as required.

Any serious heat loads on the He cooling for the superconductors is going to be very expensive.  You are going to have to do better than a guesstimate on that.

At the 100 MW level the difference between a 5 MW cooler and a 30 MW cooler is serious capital.

Science prototype (WB7/8), Engineering prototype WB9, Power production prototype WB10.
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/17/2007 01:28 AM
Quote
Tom Ligon - 16/4/2007  5:08 PM
At present, it is neither the physics nor the engineering that is the hang-up.  It is the business. As has rightly been pointed out, at the moment the project really hangs on obtaining funds.

Typically, venture capitalists have no problem raising billions of dollars, if they can point out, say, 2-5 years in the future and say, with reasonable certainty, that the project will show a return on investment of such-and-such.

1) VCs do not give billions of dollars to any one company.  Ever.  They will give out millions fairly easily, and tens of millions less so, and hundreds of millions only infrequently.

2) In order to get this money, you need to be able to paint a plausible story about how they can get back ten times what they gave you, and in a reasonably short time (preferably low single digit years, but needing less money will buy you more time).

3) Engineering is a big hang-up.  The value of the patents on this fusion technology (which is what i assume you could expect to get from your hundred-million dollar investment) is directly proportional to how hard it is to turn this into a cost-effective way to make energy.  If it takes five years and ten billion dollars to get to a point where you have commercial breakeven, and the capital costs of the eventual power plants leave $0.005 per kilowatt hour to pay back all development costs, the first-round VCs may see nothing.  If the scale-up takes two years and costs $1B and there's $0.02 per kilowatt hour margin, it's a hugely different story.

A $200M VC round is truly immense.  Trying to raise such a round right off the bat indicates a lack of financial sophistication that will drive off people who might otherwise be willing to invest $5M.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/17/2007 01:47 AM
Venture capitalists are always looking to "get in on the ground floor."  They make it their business to analyze a new opportunity and decide what constitutes the ground floor and how high the elevator is likely to rise.  Where is the charlatanism?  Nobody should invest in this unless they've done their homework, any more than they should invest in a new cruise ship without analyzing the market, determining the ability of the intended ports to handle the ship and amuse the passengers, and considering what features the ship needs to be competitive.

The project is now on the ground floor.  Of course they'll be getting in there.  The question is, can it go anywhere?

If the superconductors are in liquid He, the intervening LN2 jacket is what will take the heat load radiated by the steam-generating jacket.  That jacket will remain at constant temperature, and the liquid helium should see the same heat load one way or another.  The key is to manage the temperature of the steam jacket, and use a vacuum gap and shiny surfaces to minimize radiative heating of the LN2 jacket.

I'm not sure a cooler is needed for a demo reactor.  A big tank of water and ice makes a dandy cooling system for short duration tests.  A semi trailer of ice is not outrageously expensive.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 02:42 AM
yinzer makes this point:

A $200M VC round is truly immense. Trying to raise such a round right off the bat indicates a lack of financial sophistication that will drive off people who might otherwise be willing to invest $5M.

Which is the point I have been trying to make.  

You NEED an engineering prototype.

Making enrergy has to not only be doable. It has to be profitable. You don't want to find out it will be unprofitable at the $200 million level. Better to find that out after you are only $25 million in the hole. (WB7 to 9).

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 03:05 AM
For a given flow rate pumping loss goes up as the cube of the flow rate in fixed piping. Suppose you are off by a factor of two  on your heat calculations. You need increase your flow by 2X and your pump pressure by 4X. i.e  8X the energy for pumping. That can get significant.  If you are off by 3X you need about 30X as much pumping power. Depending on the strength of your piping such a scale up may not be possible.

Those are the kinds of risks you are looking at with not doing an engineering prototype.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 03:18 AM
High risk/high reward projects are handled in steps so that the risk at each step seems reasonable to the people holding the purse.

Venture capital is all about managing the risk.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/17/2007 04:04 AM
MSimon,

If you are off by a factor of 2 in the heat load calculations, it is because the device is generating twice the power you predicted.  That's a nice problem to have.  As long as the reactor is capable of handling the intended heat load, throttle it back to the desired power.

On the financial end, you guys are largely arguing about things I've agreed with you about.  The plan of action will have to be something the investors like.

But are you guys trying to tell me that nobody ever funds anything over $200 M?  Are you telling me that, having demonstrated the reactor technology, it is impossible ever to work up to working powerplants?  Gee, I guess we'll all just have to roll over and die. Maybe VC is not the right term, though, because I see things going up all the time that take investments in the tens of billions.

If your only goal in this forum is to say it can't be done, well, go right ahead ... and hopefully the world will ignore you.  If the goal is to find some way by which it CAN be done, that's more useful.  But kindly don't flog a dead horse when I'm agreeing with you.  Yes, all investments are about managing risks.  Yes, the investors must be satisfied with that.  The project will be done in 10 little steps if that's what is asked for.  

But remember, you also stipulate a relatively short pay-back time, so if your plan requires ten years of little steps with no payback, by your own rules, its a non-starter.  

Some way, some how, this can be done.


Royal Caribbean launced "Freedom of the Seas" last summer ... anyone know what that thing cost?  My guess is it would have covered the cost of ITER.  I'll grant you, the payback is a lot more certain and faster that ITER.
Title: Re: Fusion with space related aspects thread
Post by: Avron on 04/17/2007 04:30 AM
Quote
Tom Ligon - 16/4/2007  12:04 AM
......

If your only goal in this forum is to say it can't be done, well, go right ahead ... and hopefully the world will ignore you.  If the goal is to find some way by which it CAN be done, that's more useful.  But kindly don't flog a dead horse when I'm agreeing with you.  Yes, all investments are about managing risks.  Yes, the investors must be satisfied with that.  The project will be done in 10 little steps if that's what is asked for.  

But remember, you also stipulate a relatively short pay-back time, so if your plan requires ten years of little steps with no payback, by your own rules, its a non-starter.  

Some way, some how, this can be done.


Royal Caribbean launced "Freedom of the Seas" last summer ... anyone know what that thing cost?  My guess is it would have covered the cost of ITER.  I'll grant you, the payback is a lot more certain and faster that ITER.


Needs a plan so that there are deliverables to show the progress.. and yes it could be ten steps, but each must be measable..

In terms of RCL... payback would be good ( 4 times increase in dividends is a good start)... ;)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 04:49 AM
Tom,

You have said yourself that the collector grid might oly be 80% efficient rather than the 95% Dr. Bussard expects. That is a 4 to 1 range. If the actual efficiency is only 70% that is 6 to 1. If you are off by a factor of 6 in the wrong direction you need 36 times as much pumping pressure and  two hundred times the pumping power. Suppose you compromised and locaed the required pumping power at the geometric mean of the range. If you wound up at the low end extreme you only need to increase pumping power by a factor of 15. Pressure by a factor of 6.

If all the energy goes back into the B11, p, and e no problems (other than changing the energy distributions). If it has to be absorbed by the collector grid - big problems.

You also have the problem of locating the electron guns with respect to the collector grids. You want the guns located near zero voltage  in the electrostatic field with respect to the +200 KV accelerating grid and the (aprox. ) -2.5 MV  collector grid.  That is going to be hard with electron guns longer than aprox. zero length. On top of that your +200 KV grid is going to have to support the electron current and the alpha current.  At 100 MW the alpha current is going to be 40 Amps.  At 200 KV that is an 8 MW supply.
If the machine is net neutral and the Polywell is 80% of the Magnetically Shielded Grid voltage then you are talking about a 10 MW supply.  10% of your power.  Not too different from the pumping losses at full power of a nuke.  A big engineering problem to design and build a 200 KV 50A power supply.

At 1 MW you are talking about an 100 KW supply. 200 KV at .5 Amp.  Not too tough.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/17/2007 05:13 AM
Tom,

re:cruise liners,

We have long experience building such ships and filling them with passengers. The risks are known and the rewards are comensurate due to long experience. The ship even has resale value so the sunk capital is never a total loss.

The Bussard Reactor has yet to produce as much as 1 W output and the runtimes have been well under a second at even those exalted power levels.

I for one would love this to be workable. The way to make that happen is not by scaling up by a factopr of 1E8 in power at one jump. Not even the fission nuke guys did that running a war time  tie the safeties down effort. It took about 11 years to scale up the power out by 1E8 and produce a workable submarine reactor.  Spending government money.

You haven't got government money.

By the time you get to spending $200 mil of an investors money you had better be close to a 90% sure thing. Which means knowing all the losses to much better than within a factor of 2. Better is +/- 30% or even better +/- 5% (wich is probably the lower limit of uncertainty for a scale up of 100X).

Science proof, engineering proof, power production proof.  At that point you are going to need many 10s of billions to tool up. You get the second reactor in maybe 2 years. 10 in the third year. Hundreds in the fourth year.

Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/17/2007 05:43 AM
I want it to succeed, too.  And you've got me to the point where I mostly belive that the physics could be sound.  But the way you talk about the financial aspects of things really scares me, because one interpretation of the statements is a very deep lack of financial understanding, of the type that could be fixed with a few hours or days of study.

Royal Caribbean already has a fleet of cruise ships, knows how to run them, knows how much it costs to run them, and can probably make an estimate of the amount of cash flow they should be able to generate from "Freedom of the Seas" to within 10%.  They're also well enough established that they can be counted on to run at a loss for a few years to avoid defaulting on bonds and paying much higher interest in the future.  The odds of losing all of your money buying R.C. bonds is miniscule; the odds of any sort of default only slightly less so.  I'd be surprised if they had to pay more than 9% interest.  Freedom of the Seas also took less than three years from being ordered to her maiden voyage, meaning that carrying the initial costs had only a minor impact.

I'd say that a conservative/wild-guess estimate of the likelihood of investors in Bussard Fusion Reactors, Inc. being totally wiped out, either through dilution in later rounds or through some as-yet-unknown-but-fatal technical hurdle is at least 50%.  Now once you get the technology to produce an effective fusion power plant, you can license it to power companies and then sell the future revenue stream to pay back your initial investors.  But you need to paint a plausible story for that future revenue stream to be probably ten times the amount of investment required, or convince enough physicists who are known by VCs that the system will work that the value of the revenue stream only has to be five times the investment required.  This is where intermediate stage reactors come in.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/17/2007 04:43 PM
All of this VC and financing stuff is predicated on the results from WB-7 and WB-8.  WB-7 and 8 should go a long ways towards proving that this concept is doable and provide a better estimate for where the future
economics are going to be.  You may not be able to predict within 5% how much an actual reactor is going
to cost, but order of magnitude understanding of the finances should hopefully be possible after WB-7 and 8.

 As has been pointed out earlier.  Those two projects should probably cost less than $3 million and that
kind of money might be fairly easy to come by.  At that funding level, it might be possible to convince people
to fund even if they think it's fairly risky.  It's not risking a lot of money.

So, where is Dr. Bussard in the process of getting WB-7 and 8 funded?
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/17/2007 05:30 PM
Quote
BarryKirk - 17/4/2007  9:43 AM
As has been pointed out earlier.  Those two projects should probably cost less than $3 million and that
kind of money might be fairly easy to come by.  At that funding level, it might be possible to convince people
to fund even if they think it's fairly risky.  It's not risking a lot of money.

It's not a lot of money.  But what's the path by which the $3M investment for these next two test reactors (I thought the/a plan was to go straight to net power production?) turns into $50M a few years down the road?  If you're trying to raise private investment, that's what you need.  Donations are a somewhat different story.

This still feels like it's the sort of basic research that is more in the realm of government or charitable foundation funding than private investment.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/17/2007 10:58 PM
Regarding the p-B11 conversion efficiency ... the theoretical maximum level of recovery is 95% with no power intercepted by the MaGrids and other intervening hardware ... that has not changed.  

If built for p-B11, I would expect the demo reactor would not attempt full-scale direct conversion.  More likely, it would have water-cooled walls (robust flow is possible here and I'm not even remotely worried about having enough cooling).  My risk reduction strategy would be to install large ports in the walls would allow small prototype power extractors to be installed once the reaction is verified to be happening.  Once it was verified that the machine could produce a large flux of alphas, it would be possible to try various bolt-on methods of power extraction to evaluate what strategy would work best.  Only after verifying it can be done would you go thru the considerable expense and extra engineering needed to immerse the entire reactor in an energy extraction shell.  

I have not asked about the present state of funding of the NPO.  I know he is in contact with at least two individuals who have money themselves and also know money people.  These are both astute businessmen, and I'm sure they're sharing their wisdom with Dr. Bussard and helping him formulate something investors are more likely to go for.  He's probably getting an earful of the same sort of things you guys are saying.

As I've said, I'm not officially part of EMC2Fusion, just a volunteer cheerleader.  The only "strategy" I am privy to is what you guys have read on the internet.  I've been presenting his notion of going straight for net power because that's what he said at Google and in the Valencia paper, and because I think it could be pulled off, if the funding were available.  But if that's not the approach investors want, obviously they won't open their wallets.

I fully expect the WB7/8 research will be funded somehow ... the fantasy is an outright grant from a few people who understand the importance, and who want to see better data before making the big investment.   The results of that work should make a big difference in their confidence in the program.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/17/2007 11:07 PM
I know this is not really an apples and apples comparison, but humor me, as this is the only application I can think of off-hand where such high power levels are coupled with a cooling apparatus.

I recall reading a few years ago that the SSME nozzles had been redesigned to allow fuel-cooling.  I think they lined the hot side of the nozzles with copper channel ... at first I was surprised by the idea that they could use copper and not a refractory engineering material, but then I realized that the load is borne by the outer shell of the nozzle, the pressures are not all that tremendous, and the copper would stay remarkably cool due to the fuel (I think it was the liquid hydrogen) flowing thru it.  The reason copper works and some fancy refractory would not is copper's enormous thermal conductivity.

We recently established the power output of each SSME is about 6 gigawatts.  Most of that stays in the exhaust, and there will be some laminar flow insulation, but still, the inside surface of the nozzles must soak up heat at a stupendous level, possibly comparable with the heat load conditions on the MaGrid in a 100 MW reactor.  Does anybody here have data on the amount of heat this system removes?  It might make a good model for a MaGrid heat shield.

For that matter, perhaps the subscale engineering model you guys want to assure that the cooling can be worked out might be first tested with rocket fuel.   Assuming you did built a subscale reactor, your power output is down by approximately R^7, so a half-scale machine would be down in power by a factor of 128.  That puts the output below 1 megawatt.  I don't think that's a high enough load to adequately test the cooling problem you guys are concerned about.  I suspect you COULD achieve the heat load on a model MaGrid with rocket fuel.  That would be a nice project for some little California rocket company that would like to be involved in this program but has no nuclear expertise.

Also, recall that Dr. Bussard believes larger MaGrids are easier to cool than small ones.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 12:16 AM
The purpose of the 1 MW model is not a full up test of the heat loads.

The purpose is calorimetry. Enough power so that good measurements can be made. Not so much that fixes are expensive.

Consider this: suppose the required flows in a major section of the reactor are a factor of 2 different from the design estimates. You will want to buy a new flow meter for that section because differential pressure flow meters respond as the square of the flow.  Too little flow and accuracy suffers. Too much and you are out of range.

A new flow meter is going to cost a lot less a for 1 MW than 100 MW.

BTW the venture capitalist is going to want to see your whole plan from WB7/8 through series production. You need a business plan.

To make this work Dr. Bussard is going to have to be replaced as CEO. He is not competent to take this to commercialization.

Once you have the science in hand it becomes a whole new ball game. The rules are different. Rare is the scientist who can manage a business.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 12:34 AM
Tom says,

If built for p-B11, I would expect the demo reactor would not attempt full-scale direct conversion.

Actually that is probably the most critical piece. Proof that you can make power. No power, no money. A good reason to make it small.  3 MV .5 A converters are much cheaper than 3 MV 50 Amp converters.

More likely, it would have water-cooled walls (robust flow is possible here and I'm not even remotely worried about having enough cooling).

That would work - cooling should be very easy at low powers. As power goes up it gets harder. Area goes up as the 2nd power of linear dimension, power goes up at the 7th power. You run into problems at higher powers.

My risk reduction strategy would be to install large ports in the walls would allow small prototype power extractors to be installed once the reaction is verified to be happening. Once it was verified that the machine could produce a large flux of alphas, it would be possible to try various bolt-on methods of power extraction to evaluate what strategy would work best. Only after verifying it can be done would you go thru the considerable expense and extra engineering needed to immerse the entire reactor in an energy extraction shell.

You greatly underestimate the value of dog and pony shows. Most people are from Missouri. They want to be shown. They want to touch. They want to see it in operation. A few equations on a blackboard, blue prints and circuit diagrams are not going to cut it. It might be more than enough for me. It will not be enough for the vast majority of investors.

Your demo should look as much like the final unit as possible. Extracting power from ports will give people the wrong impression. In business impressions are very important.

So maybe there needs to be a step between WB8 and 1 MW.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 01:02 AM
The Shuttle Main engines operate at about 6,000 deg F at about 2,000 psi. Pumping pressure is about double that.

I'm doing some calculations based on 2,100 F 3,000 psi water. Two stage to orbit with a cluster of 5 rockets shouldn't be too hard. 3 booster stages with their own tanks and Bussard reactors.  A main tank with its own reactor and an orbiter with a reactor. About 12.5 million pounds of thrust on the pad. Increasing as the atmosphere gets thinner.

3 rocket nozzles per reactor. Roughly 850,000 lbs of thrust per nozzle.

That means that you have delivered a "spare" reactor and a very large tank to orbit (200 km above sea level).  Maybe you design your orbiter so it can return the engines to earth. Or maybe you build habitats.

Most of the rocket engines I have seen use stainless steel tubing for the combustion chamber and rocket nozzle.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/18/2007 02:43 AM
The SSME are cooled with liquid oxygen at 90 degrees Kelvin.  The supercold LOX is pre-heated by circulating it around the SSME nozzle.  The LOX reaches 533 degrees Kelvin prior to mixing with the LH2 and combusting.  During the 8.5 minutes during liftoff a turbopump supplies 440 kg/sec of LOX to the engines via the single coil heat exhanger.  All of it changes temperature by 443 degrees Kelvin.  Assuming the LOX changes to gas phase almost immediately with negligible change in temperature, then O2(gas) has a specific heat capacity of 29.4 J/(K-mol), and a diatomic molar weight of 32 g/mol.  So, I get an approximate heat transfer rate of 179,082,750 Joules per second, or 179 megawatts.  If the engine produces 6 GW of power, then the nozzles must cope with roughly 2.98 percent of that power convecting though the nozzle wall, damaging it over time.  Even with this cooling system, the engines operate at over 3300 deg. Celcius, and operating lifetime of the SSME is specified as 7.5 hours.

So, if Bussard's fusion reactor has similar conditions, expect a shut-down and servicing thrice daily, ie. replacement of the magnetic coil jackets/cladding/whatever.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/18/2007 02:49 AM
Roughly how much surface area is in that SSME engine nozzle?  How much heat is captured by vaporizing the LOX?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/18/2007 03:34 AM
Semper,

The life expectancy of the SSME components has an awful lot to do with high density chemically reactive supersonic gas eroding the surfaces over which it flows.

Various surfaces in the reactor will certainly have a life limit, but not necessarily so severe.  

The Riggatron tokamak was expected to have a life of only a month or two before the magnets were trashed, and was still projected to make power profitably.

If only inner shields of the MaGrid need periodic replacement, that can probably be done robotically, without bringing the chamber up to atmospheric conditions.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 03:43 AM
Plasmas are good at eroding anything they come in contact with.
Title: Re: Fusion with space related aspects thread
Post by: Avron on 04/18/2007 04:48 AM
Quote
M Simon - 17/4/2007  11:43 PM

Plasmas are good at eroding anything they come in contact with.

and thus like to get contaminated... Oh, well,  back to square one?
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/18/2007 04:58 AM
SSMEs are cooled by liquid hydrogen, not liquid oxygen.  And the power required to push the coolant across the pressure drop of the thrust chamber is decidedly non-trivial.

Quote
The Riggatron tokamak was expected to have a life of only a month or two before the magnets were trashed, and was still projected to make power profitably.

The Riggatron is also probably a big part of the reason that Dr. Bussard will have trouble raising money.  It was sold as a sure thing, most physicists didn't believe in it, and it turned out not to work at all.  People will want to know why it's different this time.

Edited to add, and I feel really bad saying this, but "my research is being suppressed because other people will be embarassed" is almost always the sign of a crank.  It is true that the current administration has done a lot to break this link, but I don't feel that the rot has spread throughout the fusion community.  Rather than saying "there are only five people in the country who understand this", he should be saying "Bob, Joe, and Frank understand this and think it will work", or at the very least "Bob, Joe, and Frank understand this, but think it won't work, but they are wrong, for reasons X, Y, and Z."
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/18/2007 02:34 PM
Seems you are correct.  LOX only cools the High Pressure Oxidizer Turbopump (HPOTP), and LH2 is used to cool the engine.  The High Pressure Fuel Turbopump (HPFTP) supplies 73 kg/sec of LH2 to the engine at a starting temperature of 23 deg. Kelvin.  The coolant is fed through the nozzel and combustion chamber, vaporizing and heating up to 900 - 1100 deg. Kelvin.  That's a temperature change of 977 deg. Kelvin.  Keep in mind that I'm getting this info from various websites, none of which I consider really authoritative.

WebElements gives the specific heat capacity of gasesous diatomic hydrogen as 28.82 J/(K-mol), and a diatomic molar mass of 2 g/mol.  These are the only numbers I'm sure are correct.

So crunching all this crap together, we get a hydrogen pre-combustion heat transfer rate of 1,027,735,610 Joules per second, or a bit more than 1 GW.  If the total engine power is 6 GW, then the nozzel and combustion chamber heat load is over 17 percent of that total.

I think I previously estimated that the magnetic coils in Bussard's EDF reactor have a cross-sectional area that would block about 20 percent of ejected He ions from escaping.  So....  these are all guestimates.

As a general rule, the higher the temperature, the shorter the operational lifespan of the component.
Title: Re: Fusion with space related aspects thread
Post by: Magico on 04/18/2007 04:43 PM
Noticed this added to the bottom of http://www.askmar.com/Fusion.html.

"Note: As of April 2007, Dr. Robert Bussard, stated that due to the publicity from his 11/9/2006 talk at Google and the 2006 Outstanding Technology of the Year Award, the U.S. Navy sent him a contract extension to continue his fusion research."

Hey Tom, is this correct? Has Dr Bussard had his DoD funding reinstated?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/18/2007 05:44 PM
RE: Contract extension.  That's the first I've heard of it.  I certainly hope so.

I have no doubt the perception that the Riggatron "didn't work" causes Dr. Bussard some credibility issues.  In fact, the funding history of the Riggatron was rather like the Polywell.  Bob Guccione originally intended to fund the Riggatron to something like $150M, using projected revenues from an Atlantic City casino.  In fact, he was unable to get the permits for that enterprise, and so had to cut the project off at about the $17M level.  It was never built, so nobody knows if it would have worked.  Dr. Bussard still believes it was the one tokamak design that had any chance of making breakeven.

Even if it would have worked, it was a nasty little neutron-maker with a very short live expectancy.  The Polywell concept grew out of frustration over the difficulties in confining ions with magnetic fields, which was the big cost item in the Riggatron, as it is in all tokamaks.

Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/18/2007 05:49 PM
I hope that they don't just re-fund it and then put the lid back on for publishing.

Add funding to shut down the release of information.... Possibly at the behest of the DOE.

Of course that would be a conspiracy theory ;)
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/18/2007 07:11 PM
Quote
Tom Ligon - 18/4/2007  10:44 AM
I have no doubt the perception that the Riggatron "didn't work" causes Dr. Bussard some credibility issues.  In fact, the funding history of the Riggatron was rather like the Polywell.  Bob Guccione originally intended to fund the Riggatron to something like $150M, using projected revenues from an Atlantic City casino.  In fact, he was unable to get the permits for that enterprise, and so had to cut the project off at about the $17M level.  It was never built, so nobody knows if it would have worked.  Dr. Bussard still believes it was the one tokamak design that had any chance of making breakeven.

The wikipedia notation that all experimental tokamaks to date have not had a lithium blanket and thus been configured more or less identically to the final Riggatron design, and still have yet to come within shouting distance of a fusion yield of unity after billions of dollars of investment sounds both plausible and damning to me.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/18/2007 07:30 PM
The fact that the Riggatron had its magnets immediately adjacent to the plasma torus was supposedly one of its key differences from the other designs.  Working the fields thru 5 meters of lithium from superconducting magnets on the outside, you have serious field stability issues.  The field can wriggle around like a slinky.  The Riggatron supposedly had better field stability.

I've seen some indications that, post-Riggatron, other tokamak problems have been identified that were not evident when that device was being built.  

In any case, maybe the most damning thing is the experience left Dr. Bussard totally down on tokamaks.  Even if he believed the Riggatron would have worked, it is quite clear that he wound up feeling the thing was not practical, at least for the funds he had available.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 07:34 PM
yinzer says:

And the power required to push the coolant across the pressure drop of the thrust chamber is decidedly non-trivial.

The pumping pressure is about double the combustion chamber pressure. Which means a 2,000 psi pressure drop - most of it in the engine. The engine is running at a temperature (about 6,000 F) that will vaporize any known material.

Water cooling should be more effective because of the higher heat capacity of water vs H2. The engine will also be running at a much lower temperature - 2,000 to 2,500 deg F.

I used this:

Rocket thrust/flow engine calculator. Stick with the H2 - O2  fueled engine. Lower the temperature to 2,000 to 2,500 F.  Increase the chamber pressure to max (about 3,000 psi). That will give you some exhaust velocities to work with and ISPs.

From there you can easily figure the size of the rockets and the amount of reaction mass.

I have a spread sheet for a very rough two stage to orbit calculation. Let me know if you are interested. I plan to pretty it up pretty soon.

I'm figuring on a 5 rocket cluster with 3 boosters, one powered main tank, and a powered orbiter. The boosters are all water "fueled". The boosters drop off at 1/2 final velocity.  Once you reach 1/2 velocity either the main tank engines or the orbiter engines would have enough ISP/thrust to get you to orbit. In addition it is probably possible to carry enough reaction masss in the orbiter to allow one go around on landing. Safety goes way up.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/18/2007 07:39 PM
That calculator sounds interesting.

Can it work with watts and any reaction mass?  I'm going to need to write one of those myself anyway.  I did it long ago, but lost it.

Dr. Bussard can do the calculation off the top of his head on a blackboard ... I need to think about it a while.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/18/2007 07:43 PM
I seem to have found Tom Ligon's listing at the ISDC site:

http://isdc.xisp.net/~kmiller/isdc_archive/isdc.php?link=personSelect&person_id=516

More general track info:

http://isdc.nss.org/2007/program.html

This is heartening.
Title: Re: Fusion with space related aspects thread
Post by: MKremer on 04/18/2007 07:56 PM
Quote
M Simon - 18/4/2007  2:34 PM
Water cooling should be more effective because of the higher heat capacity of water vs H2. The engine will also be running at a much lower temperature - 2,000 to 2,500 deg F.
Fine so far.
So what happens to all that flowing H2O that the tremendous amount of heat has been transferred to?
What type and size of radiators would be needed to dissipate enough heat to again allow the flowing H2O to re-absorb that initial amount of heat transfer? What initial volume and pressure and temperature would be required?
Is there enough allowance for the extra H2O mass (and associated storage/pumps/monitoring hardware) to be viable?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 07:59 PM
I just give the reaction mass.

Once you have the mass flow rates (given in the engine calculator) and delta T you get your steam tables out and convert to BTUs/sec or watts.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 08:05 PM
You don't radiate the heat. You feed the heated water/steam into the reactor and heat it further and then exhaust it through the engine. No wasted watts. No radiators.

While the "rocket" is rocketing reaction mass cools every thing.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 08:16 PM
The correct url is:

http://www.askmar.com/Fusion.html

Or

askmar.com/Fusion
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/18/2007 08:17 PM
The advantage of the Riggatron was to be that the magnets were close to the plasma so it was easier to control.  However, all experimental tokamaks to date have had the magnets next to the plasma anyway, on the theory that once they got to breakeven they could then figure out how to add the lithium blanket required for power generation.  So the distance from the 2007 state of the art to power production may be smaller for the Riggatron than for a conventional Tokamak, but it's still non-zero.  And this is after pouring billions of dollars into it, as opposed to the $200M that would supposedly make the Riggatron a sure thing.

Also, LH2 is a much better coolant than water as you can easily raise the temperature of the coolant 500 deg Celsius, and it doesn't become corrosive at high temperatures.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 08:37 PM
The corrosiveness of water can be controlled by choice of metal and pH.

Nukes are designed to run with high neutron fluxes and high temperature water (1,000 F at hot spots I believe) for 50 years. The key is a lot of stainless steel and pH control. Rockets with a 100 hour (1,000 launches) lifetime shouldn't be too hard.
Title: Re: Fusion with space related aspects thread
Post by: MKremer on 04/18/2007 08:39 PM
Quote
M Simon - 18/4/2007  3:05 PM

You don't radiate the heat. You feed the heated water/steam into the reactor and heat it further and then exhaust it through the engine. No wasted watts. No radiators.

While the "rocket" is rocketing reaction mass cools every thing.
Ah... OK, makes a lot more sense that way.

Still... where's all the water come from? Is all that H2O mass planned with the initial launch, and how is it supplied (or where does it come from)?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/18/2007 09:29 PM
where's all the water come from?

You carry it in tanks. Earth to orbit is rough because of the mass required to get enough thrust.

Once you get into space any amount of thrust (within reason) is useful if you can keep the thruster going long enough.

Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/18/2007 09:41 PM
Also... my understanding is that these fusion reactors would require electrical power of several percent of total fusion power to power the grids and such.  The weight of that much electrical power handling equipment would almost certainly rule out earth to orbit applications.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/18/2007 10:02 PM
Quote
askmar.com/Fusion
It's two orders of magnitude below the $200 million Dr. Bussard says he needs to produce a full-scale 100mw system

So that sounds like...2 million?
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/18/2007 10:12 PM
As for staging.  That may be less essential than with a convential rocket.  Conventional rockets have a
fairly low ISP, so their mass fraction is very low.  Staging is needed to raise that mass fraction up to
something usable.  A Bussard rocket would have a far greater ISP which gives a much higher mass fraction.
Staging is less neccessary.

Also....

Typically, but not always, with multistage rockets.  The upper stages have a higher ISP fuel at a lower thrust.

But when changing fuels, one needs to change engines.  A LOX / RP1 engines won't burn hydrogen for example.

So, when switching to the higher ISP fuel, one needs to turn off the lower ISP fuel engine.  It makes sense
to jettison the low ISP engine and tank at the same time.  Hence staging.

With a Bussard rocket the typical reaction mass materials that have been discussed are H2 and Water.

It is very probable that the same rocket can handle both since no actual combustion is occurring.  I'm not sure if a pump can be designed to handle both liquids.  That might be really tricky.

Since water is fairly dense, the water tank wouldn't be very large or heavy, so it might not be worth dumping the water tank.

Now that I think about it.  Perhaps the water tank and water pumps could be in the form of strap ons.

They would be jettisoned at relatively low velocities and altitudes, so they may be recoverable.

Most of the boost would be done with LH2 which would have a low thrust but super high ISP.  In fact LH2
at even moderatly hot temperatures has a much higher ISP than even super hot steam.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/19/2007 01:18 AM
In terms of getting to orbit ISP (when you have a separate power source) makes very little difference. The big thing is the exhaust velocity. That determines how much reaction mass you need. Where H2 helps (at a given temperature and pressure) is that the low molecular weight (2 vs 18) increases the exhaust velocity by a factor of  3X. What you want to avoid is H2 spewing on take off. However, you then have to change from water to H2 in flight for 1 or 2 of the engines. Tricky.

Staging does help. You could do single stage to orbit but the rockets get really huge.

A two stage affair delivers a working reactor and a 27 ft dia  150 ft. tank into orbit along with an orbiter weighing 100 tons with its own power source.

Electrical conversion weight is a function of voltage and frequency. Not much can be done about the HV. Frequency can be upped by using Power MOSFETS. One way to keep the weight down is to operate the reactor at low power for long duration missions.




Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/19/2007 01:02 PM
Quote
M Simon - 18/4/2007  9:18 PM

In terms of getting to orbit ISP (when you have a separate power source) makes very little difference. The big thing is the exhaust velocity. That determines how much reaction mass you need. Where H2 helps (at a given temperature and pressure) is that the low molecular weight (2 vs 18) increases the exhaust velocity by a factor of  3X. What you want to avoid is H2 spewing on take off. However, you then have to change from water to H2 in flight for 1 or 2 of the engines. Tricky.

Staging does help. You could do single stage to orbit but the rockets get really huge.

A two stage affair delivers a working reactor and a 27 ft dia  150 ft. tank into orbit along with an orbiter weighing 100 tons with its own power source.

Electrical conversion weight is a function of voltage and frequency. Not much can be done about the HV. Frequency can be upped by using Power MOSFETS. One way to keep the weight down is to operate the reactor at low power for long duration missions.

ISP is directly proportional to Exhaust velocity  
ISP ( in seconds ) = Exhaust Velocity ( in m/sec ) / 9.8 m /sec^2

Staging only becomes necessary and practical when three conditions are met the delta V required is high,
the ISP is low, and the required thrust to weight ratio is high.

Example surface to LEO with chemical engines.

Delta V is high.
ISP is relatively low for chemical engines.
Thrust to weight ratio required is high to reduce gravity losses.

The high thrust to weight ratio requires a big heavy engine at the start when you have a lot of fuel.  Staging
allows you to drop that big heavy engine and associated tanks after most of the fuel mass is burned.
At that point a smaller second lighter stage engine can provide sufficient thrust to weight ratio to keep
gravity losses down.  You don't have to carry the big heavy first stage engine and tank all the way to orbit.

With staging on a chemical rocket going from the surface to LEO you can raise the payload mass fraction
compared to a single stage rocket.

With a bussard rocket, the equations are a little different than for a chemical rocket.

First off the ISP can be higher.  Second their is the possibility of the same engine being able to vary the ISP
and thrust to weight ratio.

Because of that the need for a multistage rocket is not as compelling.

It may still be necessary, but maybe not.

Or possibly a hybrid rocket, with solid boosters for stage one and a bussard rocket for the upper stage.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/19/2007 01:27 PM
I was going by what the simulator said (maybe not wise). The simulator said that for a given temp and pressure the exhaust velocity was constant despite increased ISP as the back pressure on the engine was reduced. Exhaust velocity determines mass ratios.

I was designing for an easy to build engine. One where the technology is not bleeding edge.

You can get super high ISPs by sending a few lbs a second of H2 aft at 1E6 ft/sec. No one knows how to do that at reasonable size and weight (at this time).

What I am proposing is easy - relatively low stress - sure to succeed design.

If you intend to lift 100 tons into space you are goning to need around 200 to 300 tons of thrust steady (for about 10 to 15 minutes) to get into orbit with a high ISP engine. No one knows how to do that kind of thrust with high ISPs (1E6 or better) with the exhaust at atmospheric pressure.  Even with high ISPs (in the 1E6 range) you are going to need a few tons of reaction mass to get to orbit.

I have an update on Dr. Bussard's Funding:

http://powerandcontrol.blogspot.com/2007/04/good-news-fusion-project-funded.html
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 04:08 PM
One reason favoring staging is based on the fact that optimum nozzle design depends on atmospheric pressure.  The amount of flare is optimized for either low or high altitude, or space.  This was one of the reasons for using SRBs on the STS.  That allowed them to design the SSMEs for high altitude, while the SRB's are optimized for high thrust at low altitude.

If the optimum design calls for more flare at high altitude, would it be possible to have the engine drop a nozzle liner, going from a tight flare at low altitude to a wide flare at high altitude, probably done at the time of the propellant switch?
Title: Re: Fusion with space related aspects thread
Post by: coach on 04/19/2007 04:36 PM
Tom, can you comment on the link posted above related to the Navy's funding of Dr. Bussard's work?  Hopefully, there will be enough money to finish WB7 and WB8.  This is a most exciting thread and I've been glued to all the news I could find for the last 6 months.  Forgive me if I seem a little impatient.

Coach
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 05:02 PM
I have not heard anything above what has been posted here.  I believe the program had several million left on the books, the Navy just declined to release it.

It will be interesting to see how this plays out.  With the technical details now so public, the previous secrecy stuff may not serve any purpose.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/19/2007 05:14 PM
Well, $2 million is good news indeed, that is in the ballpark of what Dr. Bussard was saying would be needed
to finish WB-7 and 8.  I do have some concerns though.

My biggest is that the Navy may clamp down and not allow Dr. Bussard to publish his results since they are funding the research.  How would we know if this has occurred?

If Dr. Bussard is wrong about the polywell device, then no secrecy is required.  Physics alone has conspired to make the information useless.

If Dr. Bussard is correct about the polywell device, then it's too late to claim National Security to stop from
publication.  The cat is already out of the bag.  Other countries who are not our friends will develop functional
polywell devices.

Since, the peaceful uses of a functional polywell are so overwhelmingly good for humanity and the US.  It
would be best to do the research out in the open.

I'm not naive enough to believe that there are no military uses for a polywell device either.  But the positive
peaceful uses for it are staggering.  And widespread use of a polywell for power generation has an unexpected national security benefit to the US.  It would reduce the funding available to some countries
who are not our friends.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/19/2007 05:26 PM
When I was talking about high ISP, I had in mind numbers of over about 700 seconds.  ISPs in the 1E6 range
are for use once orbit has already been acheived when thrust and thrust to weight ratio are largely
irrelevant.

As for a dual fuel motor.  Perhaps that would be for a second generation vehicle.  Nobody has ever built
a functional Bussard Rocket yet.  And to my knowledge, nobody has built a rocket capable of changing fuel
in mid burn either.

So, perhaps go back to a pure LH2 Bussard rocket with solid fuel boosters, possibly as strap on for thrust
augmentation at the beginning.

A don't think that a Bussard rocket using steam for reaction mass is going to compare favorably to a chemical engine burning LOX/LH2

Compared to say an RS-68, a Bussard rocket using steam is going to have.

1) A lower temperature
2) A lower ISP
3) A lower thrust to weight ratio

Going to LH2 will provide a higher ISP than any chemical engine could reach.  But the thrust to weight
ratio will be so low that gravity losses will wipe out any advantages that high ISP can provide unless that
rocket was an upper stage where thrust to weight ratio is not as critical.
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 04/19/2007 05:30 PM
Quote
BarryKirk - 19/4/2007  11:14 AM

If Dr. Bussard is correct about the polywell device, then it's too late to claim National Security to stop from
publication.  The cat is already out of the bag.  Other countries who are not our friends will develop functional polywell devices.

Since, the peaceful uses of a functional polywell are so overwhelmingly good for humanity and the US.  It
would be best to do the research out in the open.
I would agree — in fact, if it is workable, then probably the best way to get to the finish line first would be to turn loose as much American ingenuity on it as possible, in the form of both government/academic researchers (e.g. U. Wisconsin) and businesses.  If they do this openly, we have a good chance of having the world's first practical fusion plants.  If they try to keep a lid on it, they'll just be slowing down our own progress, and making it comparable to what dozens of unfriendly nations could each do.

But then, I'm not the military.  Their thinking may be different.

Quote
I'm not naive enough to believe that there are no military uses for a polywell device either.  But the positive peaceful uses for it are staggering.  And widespread use of a polywell for power generation has an unexpected national security benefit to the US.  It would reduce the funding available to some countries who are not our friends.
Yes, very true (and not really all that unexpected — this is one of the stock reasons given for reducing our dependence on oil).  One can hope.

Tom, you're preparing a talk on the subject... surely this entitles you to give Dr. Bussard a call and get an update on the situation?

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 06:16 PM
I sent an e-mail last night.  He knows I'm scheduled to speak (and he asked me if I would do it).

I got the impression that the former secrecy was all one department versus another department, not actually national security!  And it was not as if the other guys didn't know about it.  Depressing, and silly, situation.  I'd say the cat is pretty well out of the bag at this point, but time will tell what the guys signing the checks have to say.
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/19/2007 06:33 PM
Quote
BarryKirk - 19/4/2007  10:14 AM
If Dr. Bussard is correct about the polywell device, then it's too late to claim National Security to stop from publication.  The cat is already out of the bag.  Other countries who are not our friends will develop functional polywell devices.

How does this square with the assertion that only 5 people in the country understand this?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 07:15 PM
That's probably about the number of people who know what is in the EIXL model, in detail.

Enough constuction details have been released that I think anybody with the money and skill could build a working machine.  They just won't understand completely WHY it works without either EIXL, or reconstruction of something functionally equivalent from what has already been published and the description in the Valencia report of what the fundamental components are.  That's probably a couple of years of effort for a plasma physicist and a programmer.  There's not supposed to be anything in that code which is not standard plasma physics, but the interaction of all of the equations, applied to the geometry is supposed to reveal some marvelously complex behavior of what, on the surface, is a very simple machine.

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/19/2007 08:36 PM
Does WB7 & WB8 require the 200 million? Should I assume WB7 will cost only a few (2 to 3) million, while the bulk of the 200 million will go for WB8 ?

Dr. Bussard mentions modified versions of WB-6, page 25 in the pdf:

http://www.askmar.com/ConferenceNotes/2006-9%20IAC%20Paper.pdf

Tom, would this be a jumping off point considering the Navy funding, a modified version of WB-6, then moving to WB-7?

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/19/2007 08:48 PM
Barry says:

A don't think that a Bussard rocket using steam for reaction mass is going to compare favorably to a chemical engine burning LOX/LH2

In what way?

Water tanks are cheap. Low temperature (2,500F) engines are cheap.  Water is cheap.

Thrust is strictly a function of how fast you can heat the reaction mass and the size of the engines.

There is no way you are going to use H2 on the boost from the pad. Too dangerous.

The advantage of the all H2O design is that you have 5  identical power plants.

I have run the numbers and the design is doable. Booster tanks are 27 ft dia about 50 ft long. Orbiter tank is about 150 ft long. Total thrust in the 12 million lbs range.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 09:00 PM
FogerRox,

WB7 and WB8 are a matched set, a truncated cube and a truncated dodecahedron, about the same size.  Both of them are intended to be run for a program whose cost has been estimated between 2 and 5 million.  The program can probably be done for the lower price, with the high-end estimates including more work planning a net power reactor, or at least the follow-on model.  

WB7 would be a more solidly built version of WB6, possibly with minor refinements to further reduce electron losses, which should produce more robust results (hopefully tens of millisecond or longer fusion runs ... I think some seconds are probably possible).  WB8 would determine if the truncated dodecahedron does, in fact, run several times better than the truncated cubes.  Running both would determine the geometry to be used in follow-on work.   These devices would be somewhere in the 0.15 meter coil radius range.

Because the program will be able to start up in a new location with adequate power, I see no reason why the project needs to be capacitor driven as he states.  The drive conditions during the deep potential well were actually do-able for a conventional power supply.  Capacitors might be used to supply start-up power to get the ion population established quickly.  If the fuel delivery can be worked out, I suspect it will be possible to avoid Paschen arcs and the machines should be able to run quasi-continuously, at least as long as the magnets can stand.

200 million is supposed to be enough to build a net-power p-B11 demonstrator, with about a 2-meter coil radius.
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 04/19/2007 09:01 PM
Quote
FogerRox - 19/4/2007  2:36 PM

Does WB7 & WB8 require the 200 million? Should I assume WB7 will cost only a few (2 to 3) million, while the bulk of the 200 million will go for WB8 ?
No, and no.  The $200M occasionally mentioned is what would be needed to build a full-scale, power-producing fusion power plant.  WB7 and WB8 are (AIUI) subscale devices (which Bussard has occasionally expressed a desire to skip entirely) which would further refine and demonstrate the results obtained with WB-6.  For this, he's mentioned a need of $2M; Jim Benson said (probably more realistically) that it would take $5M.

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/19/2007 09:08 PM
Barry,

SRBs are expensive.  Hard to build. Dangerous to be around.

With the all water design you just inspect and refurbish the engines and refill the tanks with water.

The only expendable is the orbiter tank. You bring the orbiter tank engine back in the orbiter.  If you don't need it to power your space station.

You want to build a space station? Design the orbiter tanks to bolt together. About 150 ft long. 27 ft dia. A lot of space.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/19/2007 09:19 PM
Why do people always say that a rocket will have 'high thrust' or 'high Isp' ?  The former is just momentum change per second, the latter is just momentum change per unit weight of fuel.   The numbers you get are a result of the engine design.

With LH2/LOX combustion, the theoretical momentum change is limited by the heat of combustion, and the length of the nozzle to diffuse and direct the explosion.

With ion electric, the theoretical momentum change is limited by the electrical power available, and the rate the propellant is fed into the nozzle.

There are no solid numbers here, unless you're talking about an engine that's been built and tested.  With future technology these numbers can change.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 09:22 PM
MSimon,

In fact, an often overlooked fact is that at about 6 minutes 30 seconds into a launch, the Space Shuttle begins a long shallow dive in preparation for jettisoning the external tank.  That puts the tank on a trajectory to land in the Indian Ocean.  Without an OMS burn following ET sep, the Shuttle would go right in with it.

In essence, they're actually throwing away some launch capacity to keep from putting the ET in orbit, a fact that many people have bemoaned as a waste of perfectly good shells for building stuff in space.

It would be great to be able to design tanks that are suitable for second use in orbit.  Tanks for plain water would be simpler than STS external cryo tanks, and may be more easily adapted.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 09:34 PM
Nothing future about it ... ion and arcjet engines have been built and operated in space, at variable thrust and Isp.

It is all about picking the trade-off based on what you want the motor to do, with the extremes of the envelope set by available power, if thrust must overcome gravity, and just how hot you can manage to get the reaction mass.

At a given power (assuming nuclear or solar power is available for an indefinite period), you have the option of high mass flow and high resulting thrust, at the cost of less "burn time".  Use that for launches against gravity or for short trips with higher acceleration.  Think 1200-ish seconds for flights to the Moon, using Dr. Bussard's examples of systems he thinks could be built around p-B11 reactors.

For intermediate missions, back off the reaction mass flow and use the fact that you can deliver power indefinitely.  If you have the luxury of more available power, you could up the power while reducing the mass flow, and maintain constant thrust ... required power increases as the square of the inverse of mass flow, I think.  But we all know what we're going to do is run at full power and just adjust reaction mass.  Think Isp values of 4000ish for flights to Mars.  Much higher Isp values probably mean you never reach top speed.

For very long duration missions, like Titan or the Oort cloud, you are willing to take a longer time accelerating in exchange for a higher top speed.  There you might lean the mass flow out, resulting in an anemic thrust but Isp of 50,000 sec or higher.
Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/19/2007 11:01 PM
The shuttle does not throw away launch capacity to prevent putting the ET in space.  It needs to reach orbital velocity before falling out of the sky; flying a lofted trajectory early on extends the time available to do this.  The shuttle is gaining energy throughout the entire powered flight phase, and when the ET is jettisoned is a little short of orbital.

Next, in terms of thrust specific impulse and such, "high" and "low" are relative terms.  Exhaust power in watts is equivalent to one half the thrust in newtons times the exhaust velocity in meters per second (specific impulse in "seconds" times the force of gravity).  12 million pounds of thrust at a specific impulse of 400 seconds works out to an exhaust power of roughly 21 GW.  Needless to say, this number is very very high indeed.  If you have to deal with any noticable fraction of that as electricity (to power the containment / heating / acceleration grids / magnet refrigeration), you will be in a world of hurt, or at least very heavy switching equipment.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/19/2007 11:22 PM
Viz,

Yup.  A slide in my talk will throw some numbers up comparing state-of-the-art in electric propulsion versus what kind of power we would like to be able to master, thusly:

DS1, xenon ion, 2.3 kW, 93 mN, Isp 2000-3000

ESEX:  ammonia arcjet, 27 kW, Isp 500-1200 sec

(I think an arcjet flew recently in the 120 kW range)

Late-model Piper Supercub (180 HP prop), 134 kW

SSME's:  18 GW.

We do definitely have a way to go.  And on this subject, I guarantee there will be no sudden jumps from 120 kW to 6 GW thrusters.  But that's clearly the kind of thing we need to do if we ever want to go zipping about the solar system like Flash Gordon.
Title: Re: Fusion with space related aspects thread
Post by: coach on 04/19/2007 11:56 PM
Tom, if the Navy money comes in how difficult is it going to be to get the lab set up again and rehire the three researchers who now work for SpaceDev?  Due to the seemingly limited number of qualified people for this project, this seems critical.  Will the lab be in a new location?

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 12:37 AM
That could go either way.  Dr. Bussard might decide to set up close to home near Santa Fe, because his health makes him reluctant to travel much, or he might set up near SpaceDev in San Diego/Poway.  A lot will ride on how personally involved he needs to be in the project, and how willing the old employees are to come back or move, and if Jim Benson wants to be part of it.  

I think he may have a couple of young physicists who are hoping to join him when he has some funding.  One of the former employees is undoubtedly one of the people he says understands the device, but I'm not sure that individual went to SpaceDev.  Another, from an earlier time, is a physicist programmer who ended up in the computer gaming business, who might be tempted back if funding is restored.

The largest thing he has in storage is the big vacuum tank, an expensive and very nice item (my design :-)).  It can be transported on a flat-bed truck, so it would not be difficult to move to a new location.  A good rigging team can unload and position it in about two hours.

I think he will be looking for a more isolated location where he does not need to worry about irradiating his neighbors with neutrons, but extreme distance probably is not required.  He will want plenty of power, maybe a few thousand amps of 208 three phase instead of the 600 A that hampered him in the last location.  It might even be that he can find an existing lab near LANL that might have the high voltage supply and magnet supplies he needs left over from some other plasma project.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/20/2007 12:48 AM
yinzer says:

Next, in terms of thrust specific impulse and such, "high" and "low" are relative terms. Exhaust power in watts is equivalent to one half the thrust in newtons times the exhaust velocity in meters per second (specific impulse in "seconds" times the force of gravity). 12 million pounds of thrust at a specific impulse of 400 seconds works out to an exhaust power of roughly 21 GW.

The specific impulse I was working with was more in the 200 to 250 range. Piping around 2,500 deg F steam is going to be tough enough.

The power would be divided among 5 reactors - 3 boosters, 1 main tank engine, 1 orbiter engine.

I was planning a D-D reaction so the neutrons heat the water directly.

No doubt my system could be improved on. What I wanted to do was to start with the simplest, moderate technology solution.

A maglev track a few miles long could reduce the mass to orbit. With such a "sling shot" H2 reaction mass could be workable. Venting for take off would be no worse than the shuttle. I'll work out the requirements assuming 3X the exhaust velocity (24,000 fps).

==============

With H2 single stage to orbit is feasible. The reaction mass tank is about 200 ft long at 27 ft dia. Which would be reduced some with a sling shot final velocity of 450 mph. What the mag lev track really buys you is that the vehicle is not sitting still when it starts spewing H2.

Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/20/2007 12:54 AM
Let's compare a Bussard rocket using steam to a LOX/LH2 chemical rocket like the RS-68....

Both engines output pure steam.

The Bussard rocket at 2,500 F

The RS-68 couldn't find the operating temperature but for the Space Shuttle Main Engine it is 6,000 F

Let's assume that the RS-68 is running at 5,000 F which is probably close to the ballpark.

For the RS-68 Thrust to Weight Ratio: 51.20... Could a Bussard rocket reach that thrust to weight ratio?  Let's assume it can.

The ISP of the RS-68 is 365 seconds at sea level.

I'm going to guess a water Bussard would have an ISP around 260 seconds....

As for thrust, it is not strictly a function of how fast you can heat the reaction mass....

You need to pump that reaction mass and those pumps are not light weight.

In fact for most liquid fuel chemical rockets, most of the engine weight is the weight of the pumps.

Now you have the advantage with a Bussard rocket that you only need one pump because it is a monopropellant and the reaction mass is water
which is fairly high density.  The high density reduces the pump size, mass, and horsepower requirements.

But you have the mass penalty of the Bussard reactor which a chemical engine doesn't have.

So, let's assume that the Bussard rocket on steam has a similar thrust to weight ratio of the RS-68, but a vastly inferior ISP

That is why I don't think that a Bussard rocket using steam for reaction mass is going to compare favorably to a chemical engine burning LOX/LH2
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/20/2007 01:24 AM
Barry ,

The water engine will be bigger.

No doubt. The question re: better to me is not size. It is cost. If the water engine is 10X larger but the cost is 20X less per unit weight you have cut your costs in 1/2.

Also re: pumps. The water engine is operating at lower temperatures so that means the cooling channels can be larger lowering the delta P required for pumping. About 1/2 the shuttle's H2 pumping energy goes to getting the H2 through the engine plumbing. The other half raises the combustion chamber pressure.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/20/2007 01:27 AM
440 volts might be a better bet. Used for large motors.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 01:34 AM
Not unless you can get the steam hotter than any heat exchanger material I know of.

This is probably why I've never seen Dr. Bussard propose such a design.

His SSTO nuke used a relativistic electron beam to heat water.  

I've worked with a hardfacing apparatus called "plasma spray", which fires a powdered metal to be sprayed thru a small copper nozzle that looks a lot like a rocket nozzle.  An electric arc from arcwelding equipment drove it, maybe a hundred volts, and a few hundred amps.  Resulting temperatures were around 20,000 Kelvins.  I would expect arcjets and hall thrusters to get up in this range as well.  The question is, how to do it in the hundreds to thousands of megawatts?

In the case of an electric thruster, you don't need to worry about the mach 1 choke point at the throat of the nozzle.  You can pass a liquid in that point, apply the arc when actually in the expansion nozzle.  In principle, given the huge energy required and electrodes that can stand it, the power density could be higher.

Big ifs.  But obviously desireable if we can get the electric source to work.

So maybe, until then, hydrogen will work?  I don't like SRB's, but they are simple and they work, so maybe throw those in for the first 2.5 minutes or so of launch, if really, really necessary.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/20/2007 01:44 AM
No heat exchanger required. Direct neutron heating. D-D fuel.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/20/2007 01:47 AM
440V (480, actually) is used for small motors (900HP and less).  Large motors (1000HP to 25,000HP) usually run on 2400-6900V.  The 18.5MW (22,500HP) direct-drive fan motors at the NFAC run on 6900.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 02:08 AM
If it will hit 6000 degrees, it should go like stink.  Although equaling the reaction chamber temperature of the SSME still puts pure water at less Isp.  The SSME runs hydrogen rich to reduce the average molecular weight.

But, overall, the STS has less Isp than the stunningly good 460 seconds of the main engines.  The SRB's will not be nearly so good.   So if this device could fly on just steam, SSTO, without requiring SRBs, overall it would probably be close to shuttle performance.

And if the steam could get significantly hotter ... it could be considerably better.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 02:12 AM
Evidently, there is no sudden influx of money from the old Navy contract.  There may have been some book-keeping so that the unspent funds are still on the books, but they evidently have not been released.  They're not "gone", but there's no immediate rush going on to unpack the equipment either.

I guess somebody must have read too much into something.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 02:22 AM
Lee Jay,

Any old power, as long as it is three phase to naturally minimize the ripple.  Most switching supplies in the size range required can use several voltages, up to around 480V.  That 2400 volt stuff sounds a bit sporty.  The old gear in storage is set up for 208, but most of it is adaptable to 480.

Now, give the project 12 kV right off a set of big old transformers of the sort the power company uses, and give me a good catalog of industrial diodes, and I'll make a power supply that will run this thing, no questions asked!  

Assuming the power company doesn't catch me doing it, and I don't end up blasted to a dark spot on the ground.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/20/2007 02:26 AM
Medium voltage power electronics (600V and below is "low voltage" in the US, [1000V and below in Europe]) is no big deal these days.  I just bought a 4160V drive and a little one at only 650kW.  The biggest motor drive in the world (last time I checked) is 125MW, and it's at AEDC, if I remember correctly.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 02:41 AM
The only thing to watch there is if he sets up in Santa Fe, or worse, Los Alamos.  They are high enough altitude that it affects switchgear voltage ratings.  There's one spec for industrial switchgear for 2000 ft and below, another goes to 6000 ft, and then the ski lodges have one all their own.  But I know they run ski lift motors at 1200 volts up at 9000 ft, so evidently all this can be done, allowing for higher price and longer leadtime for the less common high-altitude equipment.

A small problem to solve.  One thing that comes in handy in this field is to have a really good industrial electrician on call.  We were on a first-name basis with one in San Diego, but he'd be out of his depth at these higher levels.
Title: Re: Fusion with space related aspects thread
Post by: coach on 04/20/2007 02:45 AM
Most of the discussion of this thread has dealt with the feasibility of making a sustainable net power reactor and then applying it to propulsion.  Has Dr. Bussard designed any EM radiation shields for long term space travel?  Of all the challenges involved with spaceflight, this is THE showstopper for now.  No one has any really good answers for this problem.  With the dramatically improved performance of a fusion rocket, lots of H2O could be lifted for some protection but this could seriously reduce usable payload.  I think I read where the water blanket would have to be 3 feet thick to stop everything including the nasty cosmic rays.  I may be wrong on that.  What does Dr. Bussard envision in this arena.  Pure EM shielding?  Water?  LH2?  Combinations?


Coach
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/20/2007 02:56 AM
Most MV switchgear and power electronics is not derated below 2000 *meters*, not 2000 feet.  I work at 1850 meters so we just make it under the usual spec.  Some things have a derating step at 1000 meters but that's pretty rare.  In any case, it's not usually a big derating (5-10%, fan speed/power/pitch compensates for the rest).  Gas and vacuum-insulated switchgear doesn't derate at all.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 03:31 AM
If the p-B11 reactor is used as intended, the power is mostly in alphas at roughly 3 MeV each.  Alphas are generally not too bad ... they'll come to a dead stop in solid material fairly quickly, and tend not to generate much in the way of X-rays if their target is low Z.  But these alphas will be even less troublesome ... if most of the energy is extracted from them as intended, they will be pretty tired by the time they hit a metal target.  (The production of x-rays from alphas is being used on the Mars Rovers for element identification ... it is similar to energy dispersive spectrometry, and will typically show almost no x-ray output for targets below sodium on the periodic table.)

Still, about 5% of the reaction energy will probably be expressed as bremsstrahlung radiation ... x rays maybe edging into the gamma ray energy levels.  Assuming we should be so fortunate as to be able to create gigawatts, this is certainly non-trivial.

The thrusters Dr. Bussard fantasizes about use relativistic electron beams, possibly driven by about 1.3 MV coming straight off the reactors.  This makes the potential for horrendous x-rays.  But again, if the energy of the electron beam is plowed into low-z reaction mass material (water, hydrogen, methane, ammonia, or other low atomic weight/atomic number compounds), x-rays should not result.  Running out of reaction mass so that the beam hits the chamber walls would call for an instant shut-down, as enormous radiation would result, not to mention vaporizing part of the thruster.

I've always felt the best shielding is the inverse square law.  Put the engines and crew compartments on the opposite ends of a long truss, as illustrated on the ship in "2001."  Cargo and fuel pack along that to further reduce radiation as a bonus.  The crew will need shielding from all the other space radiation as well, so get any engine radiation down to well below that level and that should be as good as it gets.  Moment of inertia becomes a bitch with all the mass concentrated on the ends of a long truss, but that's only a problem when parking.

By the way, this low-z shielding trick works for charged-particle space radiation, too.  We all want nice metal walls on our spacecraft, but it is good to have sacrificial layer of plastic a mm or two thick outside of that.  Soaks those charged particles right up and really reduces the secondary radiation.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/20/2007 04:26 AM
Tom,
Thanks.
SO WB7 & WB8 are the modified versions of WB-6, at the same scale, as the Dr. mentions in the prior cited PDF. If at that point a full scale reactor for 200 million is called for, might that be.... WB-9?  Hopefull Joking..
Title: Re: Fusion with space related aspects thread
Post by: colbourne on 04/20/2007 05:37 AM
http://space.newscientist.com/article/dn11623-deflector-shields-could-protect-future-astronauts.html

This link cover radiation protection
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/20/2007 01:03 PM
I had no idea that the SSME used half of its H2 pump capacity to run the cooling loop....

One other thing to keep in mind part of the need for pumping capacity is to overcome
backpressure.  But also part of the need for pumping capacity is to overcome frictional
losses due to the viscosity of the fluid being pumped.

Now you mentioned larger cooling channels which means you are concerned with viscosity
losses.  H2 has a much lower viscosity than water.

Actually for chemical rocket engines, I'm a big fan of LOX/RP1.... Engines using that
mixture have a substantionally higher thrust to weight ratio than LOX/LH2 engines.

Thrust to weight ratio is vital because when it is raised it allows the same mass engine to
carry more fuel and therefore the burn time is extended.  Total Delta V goes up.

I guess it's all a matter of compromises.  We need to see a functioning Bussard reactor
to see what we can do with and what form it takes.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 01:09 PM
Coach,

Re-reading your question, I think you were probably asking about general EM radiation protection rather than protection against the radiation from the engines.

Everything I said was applicable, but the general problem of radiation in space still is a big problem.

The low-z shielding does significantly reduce the EM part of the problem (X and gamma rays penetrating crew areas) even though plastics don't stop x and gamma rays.  Plastic stops the charged particles from generating these in the metal skin of the spacecraft.  The charged particles emitted by solar flares and CMEs are one of the greatest intermittent radiation hazards space travelers will encounter with any significant frequency.

That still leaves the hot EM that naturally exists in space.  The only cure for that is shielding, as inverse square law does not apply against widely-distrubuted distant sources.  And the only answer to shielding is to carry well-selected and placed materials, a mass penalty.  And the solution to a mass penalty is to have the most capable propulsion systems we can devise.

Against the possiblity of major hard gamma outbursts from such things as nearby supernovae, compact core shelters (which the ISS has) will probably remain advisable.  But having habitats buried deep underground or within asteroids available as a refuge will be a side-benefit of widespread human habitation of space, made possible by those high-performance propulsion systems.
Title: Re: Fusion with space related aspects thread
Post by: coach on 04/20/2007 04:37 PM
Thanks Tom.  I was curious if a PB11 reactor could produce enough power to deflect those high energy charged particles or gamma rays.  The mass penalty might be reduced if the EM field is strong enough and shaped to be mostly outside the vehicle.  If not or if deemed impracticle I guess we'll default to water blankets.  Maybe someone will find a way to store LH2 without significant boiloff.  That would be ideal.

Habitats in the asteroids, moon or Mars can be covered by rock and dirt with little new technology.  I was curious about the travel time protection.

Coach
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/20/2007 05:00 PM
H2 has the disadvantage of lower heat capacity per unit volume. You do get a few hundred degs C more delta T (due to the cryogenic nature of liquid H2).

Plus you want turbulent flow ( high pumping losses ) in order to cool the piping effectively.

If you are running the engines at lower temperature you can use thicker tubing walls for longevity, and bigger dia piping/lower flow rates to reduce losses due to not running the system close to the bleeding edge re: cooling.

At this point in time I'm leaning to single stage to orbit using H2 and a maglev track for initial acceleration.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/20/2007 05:14 PM
Coach,

Reduced travel time is something I realized I'd overlooked earlier this morning.  If you can build a ship that gets to Mars in 6 weeks instead of 6 months, you're way ahead of the game, providing you're not a career trucker who flies all the time regardless.

I'm sure you could use the reactor to power the magnetic deflector fields, I'm just not sure that's more effective or safer than using a layer or two of polyethylene.

Catherine Asaro, a physicist and SF author, once proposed using electrostatic shielding.  Unfortunately, charging up a space habitat to repel ions makes it accelerate electrons.  If she'd turned it around, she could have made a nice fusion reactor with the setup ... with the habitat at the convergence point.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/23/2007 07:50 PM
MSimon,
You sound like someone who has experience with Naval Reactors. That "Reactor Group / Thermal Group / Electrical" etc division is exactly what Rickover did (as you must know).

I have my own opinions about NR, I'm fairly certain that they had no (at least overt) interest in pursuing IEF for exactly many of the reasons that you have cited. In fact, I would be shocked if there is not an internal paper somewhere in the bowels of Admiral Bowman's  file cabinet that summarizes a good percentage of the engineering research estimated necessary to accomplish 100 MW level polywell fusion. To not look into it would be intellectually incurious. Besides, all those Navy guys talk to each other.
NR is notoriously independant of the rest of DOE.  But when you actually get down to it, the only real downside of fission naval reactors as they currently are is the extreme cost of maintenance and support. They are reliable and, like it or not, very safe. A cost which is likely dwarfed by the required funding bulge to overcome the many problems bound to pop up with Polywell fusion. Until you get the Polywell to B-11, you have to stick with D-D or D-T. Lots of neutrons == continued requirement for RadCon controls==no change in funding for NR. NR's more worried about being able to fund its continuous requirements for existing fission reactors, not a new technology with a new learning curve and new aches and pains.
So to summarize, NR/NRL is in the position of seeing a use for polywell fusion-->too far down the road. If they fund it, they would be one of the last to get the actual benefits, because B-11 is so much harder than the neutron-heavy varieties. Meanwhile the Navy would have funded an approach that invalidates many of their existing systems while making (at least in the short-to-medium term) a much more expensive replacement....not a place any military organization would want to be in. In fact, the only organization that WOULD see a use for this( in terms of granting capabilities not currently existing), the Air Force, probably won't touch it, again, because they get the benfits so far down the road. (again, not until B-11 is available, and this time at a flight weight).
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/23/2007 08:01 PM
If the D-D version could be made to work it could be installed in place of current reactors with very little change in mechanical design.

The advantage you get is that refueling doesn't take an 18 month visit to the yards and the possibility of a reactor accident is greatly reduced.  You don't have a 2 or 10 year supply of fuel in the worst possible place - the reactor core.

The Navy doesn't need to wait until p-B11 works.

BTW back in the Old Navy ('66) I was a reactor operator. So yes. I'm influenced by that. However, the requirements of the job dictate the organizational structure. So I'm influenced by that too.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/23/2007 09:12 PM
Quote
M Simon - 23/4/2007  3:01 PM

If the D-D version could be made to work it could be installed in place of current reactors with very little change in mechanical design.
Outside the primary shields, perhaps. But all the electrical support equipment changes outside as well.

Quote
The advantage you get is that refueling doesn't take an 18 month visit to the yards
True. However, the most recent RX cores (Seawolf, Virginia, CVX) are all rated to life of ship anyway...so who cares.

Quote
and the possibility of a reactor accident is greatly reduced.  You don't have a 2 or 10 year supply of fuel in the worst possible place - the reactor core.

Philosophically, correct. Practically, there's never been a US naval reactor disaster. If you were an RO then you also know the unbelievable chain of equipment, procedural, and personal judgement failures that would be required to allow just such an event.

Quote

The Navy doesn't need to wait until p-B11 works.

BTW back in the Old Navy ('66) I was a reactor operator. So yes. I'm influenced by that. However, the requirements of the job dictate the organizational structure. So I'm influenced by that too.

I think you have the structure down, I just think it's easy overestimate the military benefit, especially in the short-to medium term. Probably better from DOD perspective to let the private sector and DOE fight this out for a while, then pick it up in a few years.

On the other hand, sad that DOE is so big-program centric. Government really is the only organization that could fund this effort to net, profitable power on a reasonably short (As in a decade) timescale.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/23/2007 09:19 PM
Nuke subs work pretty well, and would probably be about the last craft to upgrade to fusion.

But most of the surface fleet runs on oil.  The destroyers are particularly fuel-hungry, as each has four turbines not terribly dissimilar to those on a large airliner, except they drive mechanical output shafts.  I'm told that to get one across the Atlantic at full speed would require pre-positioning several fuel tankers.  The annual Naval budget for fuel is mind-numbing, way up in the billions.  Thus, they're interested in alternatives.

Not everybody is happy to have fission-powered ships in their ports.  They might not be so upset by DD fusion, even less upset by p-B11.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/23/2007 09:34 PM
Philosophically, correct. Practically, there's never been a US naval reactor disaster. If you were an RO then you also know the unbelievable chain of equipment, procedural, and personal judgement failures that would be required to allow just such an event.

Like a missile hit say? Damage control would be a nightmare.  Given my druthers I'd rather have a reactor with a small inventory of radioactives than one with a large inventory of fission products.

As you point out normal operation is quite safe.

And yes some of the control eqpt. would need to be replaced. Most of it would remain the same (steam monitoring, electrical power controls, cooling water pumps, etc.)

Life of the ship of course assumes a certain rate of power use. Suppose that rate needs to go up?

If the p-B11 can be made to work the whole Navy (capital ships down to DLs) could be nuclear. The biggest help is if we could make DDs nuclear. They can use up their whole fuel supply in a few days of carrier ops.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/23/2007 10:04 PM
Quote
M Simon - 23/4/2007  5:34 PM

The biggest help is if we could make DDs nuclear. They can use up their whole fuel supply in a few days of carrier ops.

Wow... What a logistical nightmare..
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/24/2007 01:01 AM
Then again, a carrier can use up its full supply of aviation fuel in a few days of carrier ops...and you're right back to square one.
You don't really reduce the UNREP problem until the planes are running on nuclear power as well.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/24/2007 01:15 AM
Carriers carry a lot of fuel to replenish their escorts. Cruisers as well.

If you could devote that space to JP-4 you are ahead of the game.

My ship DLGN-25 - the Bainbridge (later CLGN-25) carried fuel for the escorts (DDs).

In addition the tankers devoted to fuel oil could be used for JP-4.  Logistics is a very big part of keeping ships at sea. Any thing you can do to minimize at sea replenishment is a big logistical plus.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/24/2007 01:26 AM
Quote
cuddihy - 23/4/2007  7:01 PM
Then again, a carrier can use up its full supply of aviation fuel in a few days of carrier ops...and you're right back to square one.
You don't really reduce the UNREP problem until the planes are running on nuclear power as well.

It's not all that complicated to create synthetic aviation fuel from Hydrogen, Carbon Monoxide and water.  It's also not all that tough to create Carbon Monoxide from air, and Hydrogen from water.  All you need, besides some equipment, is massive quantities of energy.  This is one way to create planes that run on fusion.  The other way is to create planes that run on LH2.  Same issue for fuel creation (energy), very different aircraft.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: Damon Hill on 04/24/2007 03:56 AM
Liquid hydrogen is hopelessly impractical for almost any sort of aircraft, let alone military.  Hydrocarbon fuel synthesis won't be easy; the equipment might take up more room than the fuel storage otherwise saved by going to fusion power.  I think the Navy would be compellingly interested in fusion if it stands any chance at all of being practical.  The military is certainly interested in synthetic fuels and has been experimenting with them recently.

The real question remains: how close to "practical" is Bussard's work?  What's it going to take to go from proof-of-concept to multi-megawatt output reactors that are compact and reliable enough for military ops?  I don't have any sense of perspective or 'feel' for this at all, nor do I see any crash programs with deep funding in the near future.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 04/24/2007 01:03 PM
If it was practical to manufacture synthetic hydrocarbon fuel from electricity alone.

Wouldn't the NAVY already be doing that using a shipboard fission reactor as the power source?
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 04/24/2007 02:12 PM
Quote
Damon Hill - 23/4/2007  9:56 PM
Liquid hydrogen is hopelessly impractical for almost any sort of aircraft, let alone military.

Oh, I wouldn't go that far.  But like I said, aircraft would look drastically different than they do now.

Quote
Hydrocarbon fuel synthesis won't be easy; the equipment might take up more room than the fuel storage otherwise saved by going to fusion power.

That may be true, though I'm not convinced of that.  But saving space isn't the compelling reason, it's saving all those fuel transfers and the boats that go with them, plus allowing much longer missions without resupply.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/24/2007 02:22 PM
BarryKirk, exactamundo.

The reality is a MW-class IEF reactor would be a huge undertaking, requiring so many engineering breakthroughs that it is on the order of the first working MW-class fission reactor, or the first orbital rocket.  No matter how much luck you have and how much support, it is going to require an effort that costs literally billions. For the government, or for that matter for private investors, there has to be some overwhelming, compelling, mid-to-short-term reason to finance it for the first end-user, no matter what the purported eventual benefits.
-Orbital rockets got it with the inter-continental nuclear ballistic missile.
-fission reactors got it with submarines.
In both cases a capability was developed that was an entirely new capability, orders of magitude different than the alternatives (long range bombers and diesel subs).

I'm sorry to say that cost reasons, whatever the likely eventual advantage, just don't stack up all that well in the short term. The only overwelmingly different capability is the promise of a real, reusable spaceship. But that would require a lot of foresight, and there's not really long-range support for an effort that many would see as sci-fi and not to any immediate earth-bound advantage.

If the WB-6 and WB-7 follow-on produce the results Tom Ligon and Dr. Bussard think they will, perceptions might change a bit. But it will likely be a DOE project at that point.

I for one hope they do.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/24/2007 06:42 PM
Take the collector grids for instance. Assume 2.5 MeV alphas (close) and a 1% spread in energies.  That is a 25KeV variation relative to the collector grid potential. That is a LOT of sputtering energy. If you assume a 100 MW reactor the sputtering energy comes in at around 500 KW (probably some less due to Gaussian distribution around the mean).  All  alphas of lower energy than the grid can absorb head back into the reactor and get slowed further. So you have a trade off between collection efficiency and sputtering efficiency. Optimizing that is only one problem.

The real crux is proving that you can reduce the cost of electric generation by a factor of 10 or 20.  Reductions of less than 5X are going to be a hard sell.

I still think that a D-D 500 or 1,000MWth reactor would be a good bet for the Navy if you could get it to run on Cu coils. "Instant" plug in to old ships.  (replacing control cabinents and wiring is considered a minor overhaul - replacing machinery is a big deal).  Smaller machinery space for new ships due to higher operating temperatures (1,000F to 1,500F should be easy if you could make the turbines work at that temperature).  The higher temperatures may also allow oil burner retrofits (you would need to add primary coolant loop pumps, and a steam generator in addition to the reactor). What you would like is a 1 year life and 7 days to replace (old out, new in). Ten days max. to radioactive "cool". Roughly two weeks in port start to finish.

For submarines you want natural convection cooling. The high temperatures possible with a D-D reactor mean you take a smaller efficiency hit (flow rate is proportional to delta T across the reactor - in a nuke that is limited by maximum operating temperature of the core - what you want is high delta T and high output T).

Re: the Navy demand. The impetus will be the first hit on the reactor compartment by a missle or torpedo that breaches containment. Or Chemical Biological Nuclear warfare on an oil burner (with its huge demand for outside air).

The key to commercial demand is cost. The key to military demand is advantages (if the cost is within reason).

WB-7 is critical, WB-8 may be necessary.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/24/2007 07:02 PM
It is critical to find that first customer.  Once your likelyhood of success is high.

The first working nuke produced .5 watts of power, we are no where near there.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 04/24/2007 07:41 PM
The Navy seems reasonably satisfied with nukes on subs.  They did build a couple of aircraft carriers powered by them, but I think they wound up being denied access to many critical ports because of it.  That may be more of an operational problem for them that the vulnerability of the reactor (fuel tanks are a pretty bad vulnerability, too).  Also, as you pointed out, the high refueling time of the fission plants is a problem.

Fuel is a major logistical headache for them, without question, and consequently a point of vulnerability.  And it is also a reason to get shot at.  Their ability to go where trouble is increases with a workable fusion power source, and likelihood they will need to drops.

Title: Re: Fusion with space related aspects thread
Post by: yinzer on 04/24/2007 08:28 PM
Every aircraft carrier the US has bought since 1964 (or 1968, depending on if you count the contract award or commissioning of the USS John F. Kennedy) has been nuclear powered.  There is no indication that they are looking to change this.

Also this talk of "instant upgrades" is a little off base, I think.  Aren't we talking about 10-meter-diameter vacuum chambers to hold the reactor, never mind the power conversion equipment?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/24/2007 08:39 PM
Tom,

It is not the physical vulnerability that is most dangerous. It is political.

People are used to large fires. They are not used to large radiation leaks and decontaminating hundreds to thousands of sailors.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/24/2007 09:06 PM
Quote
yinzer - 24/4/2007  3:28 PM

Every aircraft carrier the US has bought since 1964 (or 1968, depending on if you count the contract award or commissioning of the USS John F. Kennedy) has been nuclear powered.  There is no indication that they are looking to change this.


Actually,  that's why the decrepit conventional Kitty Hawk (the "shitty kitty") is the only Carrier allowed to be based overseas--because the Japanese don't want a fission carrier based in Yokosuka. When it eventually has to die, we'll have to base our nearest CVN in either Hawaii or Guam.

Quote
Also this talk of "instant upgrades" is a little off base, I think.  Aren't we talking about 10-meter-diameter vacuum chambers to hold the reactor, never mind the power conversion equipment?

I don't think that's unreasonable.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/25/2007 10:12 AM
Aren't we talking about 10-meter-diameter vacuum chambers to hold the reactor,

Bussard estimates 3 meters. Add another 2 or so for collector grids and you get about 15 to 20 ft in dia. About 2X the size of a nuke reactor. Plenty of spare space (relatively) in the reactor compartment. So it could most likely be made to fit.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/26/2007 01:06 PM
What I haven't heard anything about is the superconducting magnets. Does anybody do this on a large scale presently? Outside of ITER?
Title: Re: Fusion with space related aspects thread
Post by: Crispy on 04/26/2007 02:16 PM
Quote
cuddihy - 26/4/2007  2:06 PM

What I haven't heard anything about is the superconducting magnets. Does anybody do this on a large scale presently? Outside of ITER?

MRI scanners, particle accelerators. The largest constructed so far are eight 5x25m torii for the Large Hadron Collider:
http://atlas-bt.web.cern.ch/atlas-bt/images/atlas-bt.jpg

Max field strength=2Tesla

That's a LOT.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/26/2007 03:01 PM
Wow! that's big. Sounds expensive.
Title: Re: Fusion with space related aspects thread
Post by: Crispy on 04/26/2007 03:04 PM
Very. But also far bigger than the magnets needed for this machine.
Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 04/27/2007 04:57 PM
Quote
Tom Ligon - 29/1/2007  7:41 AM


The whole key is finding a density low enough to allow decent mean free paths for the ions when transitioning most of the radius of the machine, but still high enough that fusion is likely in the high-density central focus region.  Done right, you find this sweet spot, which is not unlike finding the right fuel/air ratio to make an internal combustion engine run.


And the problem with smaller radius /lower voltage polywells is that this central focus "sweet spot" becomes too geometrically small to have any appreciable chance of ion collision ending in fusion?






Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/28/2007 03:03 AM
I threw up a dairy at D-KOS

http://www.dailykos.com/story/2007/4/27/213841/746
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/28/2007 03:22 AM
I looked at the Diary and it is interesting.

However, your peak oil poll is misleading.

We have reached the peak of cheap pumpable oil. i.e. $20 a bbl oil. At $60 a bbl there is a lot of oil in the world. Proof of that? oil production world wide is still climbing. Oil shale is now an attractive proposition. etc.

Our chief problem is political oil. i.e. the jihadis. (of course saying that on KOS would give those folks a heart attack).

In any case I'm doing promotion on the right. Do yours on the left and perhaps we can make it bi-partisan.

You might also want to put up a way to contact Senators, Congressmen, and the President so the KOSsacks can put pressure on our elected reps.

House of Representatives
The Senate
The President

*
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 04/28/2007 05:44 AM
Quote
M Simon - 27/4/2007  11:22 PM In any case I'm doing promotion on the right. Do yours on the left and perhaps we can make it bi-partisan.

You got a deal. Thats the best way.

Quote
M Simon - 27/4/2007  11:22 PM

I looked at the Diary and it is interesting.
Thanks, I have no academic background in science at this level, so its a stretch for me. I 'm probably getting a great education following this.. :-)

Quote
M Simon - 27/4/2007  11:22 PM However, your peak oil poll is misleading.

The poll was utterly tongue in cheek. There is some thought that says a poll attracts readers.... I dunno...

Do you read theoildrum.com? A lot of doomsdayers hang there, I'm not one. But yes, all the easy oil has been had.

I watched a man walk on the moon, I would love to say the same about Mars. >sigh<

Illinios? I was born in Evanston, my dad taught at University of Michigan after getting his PhD there.



Title: Re: Fusion with space related aspects thread
Post by: M Simon on 04/28/2007 06:19 AM
Thanks for the feedback.

My earliest reccolections of Illinois were changing trains in Chicago. I lived in Chi Town for a number of years. Spent a year at U Chicago before joining the Navy.

To get a working reactor space qualified would take 15 to 20 years throwing dump trucks full of money at it.  At 62 the odds of me seeing it are small. However, one plants trees for one's grandchildren.

Simon
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 04/30/2007 10:59 PM
Interesting tidbit on the Navy contract extension here:

http://advancednano.blogspot.com/2007/04/bussard-fusion-navy-contract-renewed.html


To me, this means that Bussard is still under contract and can't publish anything.  It also means that he isn't getting any funding.  To put it another way....  THIS SUCKS HUGE.

Unless someone would like to enlighten me?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/01/2007 12:13 AM
This has been the status of things since the fall of 2005 ... the contract exists, they keep doing no-cost extensions, and never send any checks.  

Evidently, in the spring of 2006, Dr. Bussard decided the publication embargo was null and void.  He has not asked me to shut up yet.
Title: Re: Fusion with space related aspects thread
Post by: Jim on 05/01/2007 12:22 AM
Looks like the "space related" aspect has died out in this thread.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/01/2007 01:24 AM
Jim - Actually, I am a rocket scientist

"Looks like the "space related" aspect has died out in this thread."

Actually it comes and goes. Perhaps you would care to restart the discussion by asking a question or making a statement.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/01/2007 12:39 PM
This is under Advanced Concepts.  Here one would find talk about unproven technology and concepts that
could lead to fantastic advances in our ability to reach and travel through space.

If a working Bussard Reactor were to be developed, then threads would start popping up about applications
including space applications.
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/01/2007 02:31 PM
Quote
Jim - 30/4/2007  7:22 PM

Looks like the "space related" aspect has died out in this thread.

It is still an active thread that keeps going and going and going...
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/01/2007 10:47 PM
Quote
Jim - 30/4/2007  8:22 PM

Looks like the "space related" aspect has died out in this thread.

I'm mind's priority, we need to get this next step funded and moving forward. The WB6 variations, which appear to be tweaks before upsized devices can be built. Which should lead to space, but its long journey, but one has to  take the first step.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/01/2007 10:47 PM
Bussard's EDF reactor can fuse protons and boron-11 while a tokamak can't ?  I've read this is because the reactor acts like a linear accelerator with a spherical focus.  Is there any possibility by scaling up that proton-proton fusion can be achieved?  After all, p-p fusion is achieved by linear accelerators.  This might make Bussard's ramjet possible.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/01/2007 11:24 PM
I've never discussed the prospect of proton-proton fusion in this type of reactor with him.  My calculations say that step yields very little usable energy, mostly from annihilation of a positron the product emits.  The payoff comes when you react the resulting deuterium.  The whole reaction string to helium yields, if I recall, about 27 MeV.

The ramjet has been criticized as being too draggy to approach lightspeed.  Dr. Bussard counters that there is a way to avoid this, by not bringing the scooped hydrogen up to the speed of the ship.  Instead, react it externally in the manner of an external combustion scramjet.  Unfortunately, for proton-proton fusion, where the reaction rate of the balky first step is the rate limiter, and full yield takes multiple steps, such a conflict may kill this approach.  As the Polywell reactors would require bringing the fuel to ship speed, they're probably stuck with the excessive drag problem.  But that does not mean an electrostatic approach won't work, or at least be part of the ignition process.  I can see funneling the fuel in to a reaction zone, where density and kinetic energy are high (even relativistic, once the ship is going at relativistic speeds), and firing a relativistic electron beam thru the center of this.  Something will happen.

At one time, I recall him saying we were probably 200 years away from knowing how to build an interstellar ramjet.  But more recently, when I was writing a ramjet story for Analog, based on a particularly nasty use Bussard had dreamed up for it, he said there actually is a means to build it.  I don't have the reference at hand, but I believe he was talking about muon-catalyzed fusion.

Also, undoubtedly, not exactly off the shelf technology, but perhaps only 100 years away?  I've not looked into it much, but perhaps it circumvents all the multi-stage difficulties above.

A hybrid design might be more credible for now.  Scoop up hydrogen, and react it with antimatter.  We at least have some smattering of an idea of how to make antimatter.  If nothing else, it might power a boost phase to reach a velocity where fusion can take over.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/02/2007 12:16 AM
http://fti.neep.wisc.edu/presentations/jfs_jannaf_1205.pdf

http://www.ibiblio.org/lunar/school/InterStellar/Explorer_Class/Bussard_Fusion_systems.HTML

QED Direct plasma thrusters
Fuel --> Exhaust
Power / Reaction
(f) Mass conversion fraction

Joules / kg
Exhaust speed  m/s
p + 11B --> 3 4He
8.68 MeV
1287
6.926 E13
11,800,000 m/s
p + 6Li --> 4He + 3He
4.00 MeV
1645
5.472 E13


3He + 6Li --> 2 4He + p
16.0 MeV
704
1.277 E14

6Li + 6Li --> 3 4He

(Combined)
20.0 MeV
564
1.596 E14
17,800,000 m/s

3He + 3He --> 4He + 2 p
12.9 MeV
437
2.059 E14
20,300,000 M/s
De + 3He --> 4He + p
18.3  MeV
257
3.505 E14
26,500,000 m/s






I remember reading about a spaceship that accelerates at one gravity, 1/2 way to Jupiter, decelerates the second half. DO these exhaust speeds allow for that level of performance?

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 01:37 AM
Those figure look like they must be direct fusion product calculations.  With no additional reaction mass, they would be better suited for very high Isp but low thrust.  To get Isp in seconds from exhaust velocity in meters/sec, divide by 1 g, 9.8 m/sec^2.  The first row gives a bit over a million seconds!  They get even nuttier from there.  All of Dr. Bussard's designs used at least some additional "dilutent" reaction mass to increase thrust.

Actual acceleration of the spacecraft will depend on the combination of thrust and mass, with terminal velocity following he classic rocket equation.  At constant thrust, acceleration will increase as fuel is depleted.

For the QED engines (Isp in the 1500-6000 sec range, designed for missions as far as Mars), Dr. Bussard's designs typically assumed fairly modest accelerations, typically in the tens of milligees for the fully fueled end, with burns that might be 20 days or so.

System thrust to mass ratios sufficient for vertical launch on Luna and Mars are in his papers.  It probably would be possible to design something that would do that for Earth, but he chose to exploit the atmosphere instead and go for an air-breathing horizontally-launched aerospace plane instead, switching to on-board reaction mass only for the last bit of kick to orbit, and circularization.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/02/2007 03:46 AM
Quote
Tom Ligon - 1/5/2007  9:37 PM

Those figure look like they must be direct fusion product calculations.  With no additional reaction mass, they would be better suited for very high Isp but low thrust.  To get Isp in seconds from exhaust velocity in meters/sec, divide by 1 g, 9.8 m/sec^2.  The first row gives a bit over a million seconds!  They get even nuttier from there.

So Isp, efficiency or acceleration per unit of fuel, of a bit over a million seconds! is "Extremely good". The Space Shuttle engines deliver about 454 seconds of Isp. But hi Isp is inverse to thrust? So strictly speaking, these sorts of devices are good for longer missions, vs orbit insertion.

.... 11,800,000 m/s  look like about 35,400,000 ft/s=6704 miles/second=403,000 mph? Thats earth to moon in 1/2 hour, LOL.

SO how long is the flight to Mars?/Jupiter?

Accelerating a ship @ 1 gee, puts things in another realm/s.
Title: Re: Fusion with space related aspects thread
Post by: mong' on 05/02/2007 11:10 AM
the exhaust velocities mentionned above are for the fusion products only (i.e: individual helium atoms). that's a very small reaction mass, I doubt any practical fusion thruster could produce more than 1000 N of thrust. and given the very heavy nature of fusion reactors, that gives a very poor acceleration

those pure fusion exhaust values are only good for eventual interstellar spacecrafts, where you don't really care how long it takes for your probe to accelerate since the journey is going to take a few centuries anyway.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/02/2007 12:51 PM
This tidbit says that as of Apr 2007, the Navy has sent Bussard a contract extension to continue his fusion research.  

http://www.askmar.com/Fusion.html

And Bussard says it was due to publicity from his Nov.2006 Google video and 2006 Tech award.  It is not referring to an existing contract from 2005.  I'm still thinking this is an actual contract extension.  Otherwise someone is lying.  How can Bussard acknowledge a contract extension and still ignore the publication ban.  And how can Bussard get funding from the private sector for basic research.  It doesn't make sense.  How do we know Bussard isn't senile?
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/02/2007 12:54 PM
There is a problem with the p-p reaction.  He2, if it existed would immediatly fission into p and p.
Deuterium is the only stable nucleus with 2 baryons.

However, the reaction is really p-p -> D2 + positron + neutrino

This reaction requires the weak nuclear force to make it go and that limits the rate.  Essentially the
cross section for this reaction is tiny.  This is actually a good thing, because if this was not the case,
then the sun and all stars for that matter would have very short life spans.

Nobody has ever explained to me why He2 is completely unstable.  Protons and neutrons attract each other in the nucleus via the strong force.  But would 2 protons have an attractive strong force?

I've never heard of a 2 neutron nucleus with no protons either.

In that case the EM force wouldn't repel the neutrons from each other.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 02:17 PM
Semp,

I'm not sure where that report came from.  Have you ever played the game of "Rumor"?  It may be that Dr. Bussard told one person the no-cost extension had been executed, as usual, and that person relayed it in the context of the other news, and that got distorted into an overly optimistic report.

Dr. Bussard may be tired, and he may be overworked, but my communications with him say he is as sharp as a tack, as usual.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/02/2007 06:30 PM
Does this graphic properly illustrate the wiffle ball idea ?

http://mywebpage.netscape.com/msimon669/MaGrid_Operating-Tom+Ligon+-+FieldnElectrons.jpg


Quote
SemperUbiSububi - 2/5/2007  8:51 AM
And Bussard says

Actually, it would be Askmark that said that, in an unattributable remark, and since the false alarm is all over the internet, and askmark has yet to post the correction, or post the latest. Well IMHO that speaks for itself. Power & Control seems capable of better coverage, due to more timely updates. My 2 cents.

http://powerandcontrol.blogspot.com/search/label/Bussard

I do a bit of blogging. And I am faced with making updates and corrections quite often. Or simply, I run into better data after publishing. IMHO Bloggers that source & cite more often, are more likely to get it right.

http://www.dailykos.com/story/2007/4/27/213841/746


Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 07:19 PM
That's 1/2 of an early draft of a picture for my new Analog article on the subject.  Let's call it a "schematic representation"

The missing left-hand side showed the magnetic fields with no electron population, so they're not in the wiffle-ball condition.  The field lines would normally extend deeper into the center in a more or less hyperbolic form.

The figure attempts to show that the high electron population "pushes back" the magnetic field to form a quasi-spherical volume, and simultaneously tends to choke down the cusp holes.   The resulting trap tends to retain electrons at high kinetic energy, but is leaky.  I show one lonely electron on an outside field line ... the finished figure adds a few more.  Note that the electron would have no reason to go to the outer walls.  It is attracted only to the magrid.  It will just follow the field lines and re-enter the inner region.  Thus, the wiffleball trapping factor and the magrid trapping factor work together to retain electrons a long time.  The figure also shows that the coils conform to the field, and don't touch.

The arrows are my attempt to show that the electron population is applying a "pressure" to push back the magnetic field.  The actual effect is supposed to be diamagnetic, a milder effect similar to superconductor levitation by the Messiner effect.

I illustrate the electron emitter on a face.  In the recent real machines, they're on the corners, due to better geometry for electron extraction.  But my 3-D drawing skills are not up to that.

Any suggestions to make it clearer would be welcome.  The article has sold, and I need to get the final version of the artwork off to the magazine.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/02/2007 08:15 PM
Quote
Tom Ligon - 2/5/2007  3:19 PM  Let's call it a "schematic representation".

Right, I think I got it.
What if a first graphic showed one magnet, and the associated field with electron flow. There would be no push back, right? Not untill all the magnets are brought together does the push back of the magnetic field result, " to form a quasi-spherical volume, and simultaneously tends to choke down the cusp holes."

Next graphic would show all the magnets brought together. Would this better describe/illustrate  the push back/quasi-spherical volume (potential well?) & the choke down of the cusp holes ?

EDIT: If I am grasping this right, I could make a crude animation & load it to you tube.......
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 08:39 PM
Interesting offer ... I've actually been working on an animation for the ISDC talk.  Dr. Bussard was not thrilled by my first attempt.

All I've got for animation is a CAD program (DesignCAD 3D) and Pinnacle 10.  I've been making a video up from a series of JPEGs, moving the particles a little on each frame.  Huge amount of work.

DesignCAD does animations, but I have not been able to coordinate all the particles well enough with that feature.

I don't know that the single magnet is all that interesting, but the field would be simple, and the electrons would follow it.

Bringing the magnets together could be modeled accurately by various programs, but I just sketched it in and mirrored the pattern.  With a low population of electrons, they don't distort the field, and they just follow the lines in and out of the magrid, with no wiffleball formation.

At very high populations (I've estimated a million amps may have been flowing in WB6 due to the injection current and the expected lifetime), the electrons are no longer having a negligible effect on the magnetic field.  I visualize the result as building the magnetic field out of sponge rubber, and inflating a balloon inside of it.  The balloon pushes back the foam, making a nearly spherical cavity, and shrinking the cusp holes.

At modest magnetic fields, the ions will not be affected much by it, so their motion is radial, formed just inside the magrid, passing thru the center, and out the other side.  They should never exit the interior of the magrid, and move fastest at the center, nearly at rest at the outer edges.

Or I could just put that figure up and wiggle my laser pointer at it!  I've got a green astronomical laser pointer that should be plenty bright.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/02/2007 08:44 PM
I'm having a hard time envisioning spherical electron flows.

Aren't the flows at right angles to each other going to interfere where they intersect?

Plus. Are all the flows in a given plane in one direction?

Or do we have a case (like some ball lightning theories) of a spinning torroid?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 09:00 PM
Individual electrons probably won't interact much at the center, but if they do the reaction should be elastic and they should just deflect but continue to move radially.  Electrons and ions see each other in passing, but their kinetic energies are far too high to allow them to recombine.  

In the case of an Elmore-Tuck-Watson gridded electron machine (a fusor for electrons), the electrons accelerate to the grid radially, then maintain a constant velocity across the interior volume (which is a free-drift region).  If the population is sufficiently dense, they form a dense zone in the center that acts as a virtual cathode (i.e. it repels the electrons).

Change the plain grid to a magrid, at low electron populations, and some electrons, those going straight across, exactly on the axis, will still do that.  Most will follow the magnetic field lines (actually spiraling around the lines with a gyroradius determined by their kinetic energy and the magnetic field strength at each location).  

When the population gets high enough to make a wiffleball, I defer to a supercomputer.  That's messy.  But the net effect is that the wiffleball excludes the magnetic field inside it, so the electrons tend to travel in straight lines, at fairly constant velocity, pretty much radially.  The interaction with the field at the wiffleball boundary will be complex, but the net result is that the electrons usually bounce off unless they hit a cusp hole.

If they hit a cusp hole, they exit, pick up a field line, and follow it around to another hole.  If they leave a face, they enter a corner.  If they leave a corner, they enter a face.

With no ions, the virtual cathode in the center slows the electrons.  But the actual operation of the machine is with nearly equal populations of electrons and ions, slightly electron-rich in most areas.  The ions are also converging, and form a virtual anode, which the electrons like.  Hence, the electrons act almost as if there is no electrostatic force acting on them at the center, and their trajectories should be about radial.

This virtual anode/virtual cathode balancing act is instrumental in avoiding bremsstrahlung losses.

The ball lightning stuff is more Paul Koloc's approach.  It may have some merit, but is a Maxwellian heat approach.  I think he is an advisor on the project, though.  Focus Fusion may be using something like thay.  They also think they can burn p-B11, and I wish 'em well.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/02/2007 09:00 PM
Tom,

Could you let us know what issue of Analog.  I'd like to buy it.

I probably should get a subscription anyway.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 09:07 PM
It is a long article, so the goal is to get it in to the December/January double issue.

I've got a Bussard Ramjet story coming out sooner, probably in the July/August issue, or so I was told last night.  That's fiction, but I use one of Dr. Bussard's p-B11-powered QED rockets to save the solar system from the worst invention he ever dreamed up.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/02/2007 09:27 PM
I got all that before I asked the question.

Except for one part. I'm having trouble imagining the wiffle ball flows. All the rest is a piece of cake once the wiffle ball flows are conceptualized.

Do the electrons follow the magnetic fields of the Ma-Grid?  If so is that the reason for having a grid with even numbers of intersecting planes at the corners? So that the electron flows into and out of the corners is balanced?

If that is the case the octahedron should be the ideal shape.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 09:50 PM
Somebody sent me an octahedron design recently.  I stared at it for a while and finally recognized why it would work.

The truncated octahedron and the truncated cube are actually pretty much the same thing.  The truncated cube has eight corners.  Move the magnets to the corners and you have the truncated octahedron, but it is essentially the same device.

Any electron that gets out of the wiffleball follows the field lines as you say.  It the interaction with the wiffleball boundary that is complex.  Dr. Bussard has a short video of a 2D 1-quadrant supercomputer run showing what happens, and I really wish I had a copy.  I only saw it once.   I do recall that inside the wiffleball, the model showed very radial flow and remarkably sharp focus at the center.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/02/2007 09:53 PM
Quote
Tom Ligon - 2/5/2007  4:39 PM

I don't know that the single magnet is all that interesting, but the field would be simple.

It helped me visualize the "push back" at the center of the device. From my uneducated point of view.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/02/2007 10:01 PM
WB-8 is supposed to be a dodecahedron, 12 sides.

I'm just curious.

What are the pros and cons of 6 sides, 8 sides, and 12 sides....

The cube has four edges per face with 90 degree angles at each edge.

The octahedron three edges per face with 60 degree angles at each edge

The dodecahedron has 5 edges per face with 108 degree angles at each edge

Well, to my uneducated eye.  If each face contains a toridal magnet.  More edges per
face would make for a smoother magnet.

Would the maximum number of edges per face be a good thing.

The dodecahedron is the platonic solid with the highest number of edges per face.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/02/2007 10:44 PM
The truncated dodecahedron should make a less-quasi, more-spherical containment for the electrons.  That should make for better convergence.  I've seen an estimate that this might lead to about a factor of 3 or so improvement in performance.  

But calculating either case rigorously on a supercomputer in 3D is a prohibitive problem.  The real proof is to build the two machines and try it.  If the dodec is really that much better, that's the form any scaled-up test should take.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/02/2007 11:13 PM
Going from the photos, WB-6 consisted of six ring-shaped magnets each making up one face of a cube arrangement.  How would a truncated dodecahedron differ from this geometry?  Would it have a ring-magnet for all ten facets?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 12:05 AM
Twelve magnets.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/03/2007 12:30 AM
Right, 12 sides.  But if you compare a cube to a dodecahedron:

[img=http://www.lsbu.ac.uk/water/images/plato2.jpg]

Suppose you have two reactors, one is a cube and the other a dodecahedron, and they are roughly the same height corresponding to a theoretical reactor radius.  The dodecahedron has smaller facets.  That is, the donut radius of each magnet is smaller for the dodecahedron.  If the circular section of the donut-magnet is not also smaller, then the dodecahedron will also have a much lower efficiency because each ring magnet will block a larger cross-section of each face, preventing Helium ions from escaping.  I guess it boils down to how the magnets are designed:  do the circular radius and donut radius scale independently, or do they scale together?  Since the reactor size is the same, this must dictate the number of windings, or how "fat" each magnet is, or whatever.  After all, this is a 3-dimensional magnetic field being generated.  A smaller, fatter magnet will block more helium ions.

How does this aspect balance against the increased yield of the dodecahedron versus the cube?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 01:23 AM
Tom,

I have spare computing power. I have a high speed hook up. Can we gather a few like minded individuals together and do some distributed computing like the SETI folks?

My raw power is a dual 2 GHz Intel box.

Do we have the code (access actually)  for the 3 D sim. and just need the computing power? Or would the code need to be developed as well?

Dr. Bussard says he needs an $8 mil. computer.  If we were willing to run distributed and had time could we start doing simulations (with videos) under the Drs. wing?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 01:44 AM
The smaller the diameter of the coil the more intense the magnetic field. I'd have to look up the scaling. It is no worse than linear. So more coils closer together should mean smaller coils for the same magnetic field. i.e it will not make a lot of difference in the "free" area.

The ions will be deflected by the magnetic fields in the same way electrons are deflected (opposite rotation). The charge will be +2 .  The speed at 2.5 Mev will be 1/25th the speed of 200 Kev electrons.  So a MaGrid that will deflect electrons will deflect 2.5 Mev alphas better.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 02:06 AM
Semper,

Like everything else, its a trade-off.  The fewer magnets, the cheaper it is to build, and the simpler that gawdawful waste heat problem of fusion products hitting the magrids will be to get rid of.  But the big reactors may have fairly skinny magnets, at least by comparison to the sub-scale models, and the more efficient dodec reactor may be able to use skinnier magnets.  Without the WB7/8 comparison data, it would be hard to judge the trade-off.

M Simon,  I don't think there has ever been 3D code written for it.  The 2D code runs were done well over a decade ago, and might be credible on a modern PC, which could conceivably keep up with an old Cray if you stripped off the Windows crud and made it pay attention.  A run might take a couple of days to simulate a few milliseconds of operation (I believe the old supercomputer took something like that).  But 3D complicates the problem unbelievably ... it goes up with some absurd power of the number of particles involved.  This is a chronic problem in simulations, not something specific to Polywells.  There are some guys over at fusor.net who have been talking about it.

At some level, that kind of support must be useful.  But I don't have the code, and Dr. Bussard would not be able to generate it on his own.  I can certainly put the offer forward, but he'll need to hire somebody thru the NPO to provide something to run.

EIXL is a 1.5 dimensional model that takes some shortcuts.  That runs in a matter of seconds on a PC, so he will need no distributed computing for that.

I'm hoping there is some way to make a simulation more like a 2.5-dimensional EIXL, something not quite as rigorous as a full particle-by-particle 3D simulation, but faster and capable of being verified by the subscale experimental results.  

Between the guys at fusor.net and here, we've got brains, computers, and interest.  Who knows?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/03/2007 07:20 AM
Electron flow for dummies:


http://www.youtube.com/v/WmMJRstMQTM
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 12:42 PM
FogerRox,

Cute!

The assembly of magnets you have illustrated with the field line show the wiffled condition.  

With no, or few, electons, the magnetic field extends more naturally on hyperbolic arcs to almost the center of the device.  Under that condition, the electrons orbit like the one you show.

With huge numbers of electrons, the field is pushed back as the animation illustrates.  This also chokes the cusps down to a smaller opening.  In that condition, one in a few thousand electrons escape to do the outer circulation, but the majority oscillate back and forth across the wiffleball volume.

The animation can't be run long enough to show electron lifetimes at a reasonable viewing speed, extimated at 100,000 transits.



Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/03/2007 12:45 PM
Tom is one of the worries with the dodecahedron that it would have more area that interacts in a negative way withthe beam?
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/03/2007 12:46 PM
So, in these cases, your simulating a polyhedron, by using circular coil magnets on each
face.

Hence the term truncated cube or truncated dodecahedron.

Are there any loses because the circular magnet doesn't conform to the polygon faces.

Would things be better off if the magnets were in the shape of polygons rather than circles?

Or conversly, by using a polyhedron where the faces more closely resemble a circle,

ie pentagon for a dodecahedron versus, square for a cube.  Does that increase efficiency.

One way to check that would be to build a octohedral device as suggested above with
triangular faces and compare that to the cube machine.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 01:00 PM
Supposedly, as long as there's an opening in each face and corner, it doesn't matter if the magnet is circular or a polygon.  The MPG machines were built from single turns of copper tubing, formed into a truncated cube.  They had weak fields and worked almost entirely by magrid recirculation, with no wiffleball.  But the grid had little area, which partly compensated.  They were capable of making some fusion.

Tony Rusi has some very pretty artwork of a truncated dodec made with polygon magnets, which I will use in the ISDC talk.  There is no reason it would not work, as long as there were no fabrication issues or mechanical problems such as stress concentrations or higher coolant flow resistance.

The truncated form is important to allow circulation of any electrons that escape the cusp holes.

By the way, look at Semper's artwork for the octahedron.  Visualize the truncation by cutting off the vertices.  The triangles then become hexagons and the clipped corners are squares.  I think you can then see the relationship to the truncated cube.  Clip the truncations harder, and the hexagons revert back to triangles, and you've got the full truncated cube.

Tony Rusi's truncated dodec did a mild clipping of the corners, so that each magnet is a 10-sided polygon, not very different from a circle.  Clip it further and you produce a pentagon.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 03:03 PM
Kevin RF,

The dodec ought to achieve a significantly higher reaction rate.

The question is not intercepting the electron beam, but what happens when you operate a reactor at full power, and some of the fusion products hit the grid rather than going out to whatever energy collection scheme is involved.  The heat load of a net power machine is non-trivial and must be removed, likely by a liquid-cooled shield.  

If the dodec is less "transparent", it would have a higher heat load.  If the ability to deal with the heat load turns out to be the limiting factor in power level of the machine, the advantage of higher output might vanish.  This could well be the case for early net-power models.

I would dearly love to be at a point where we had to make decisions like this.  What a great problem to have!  Too much power output!
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 03:52 PM
On Yahoo News today I found an article about a CO2 adsorbant-based collection system that is claimed to be able to recover CO2 from the atmosphere at levels that are potentially useful for reducing greenhouse levels.

http://news.yahoo.com/s/livescience/20070503/sc_livescience/newdevicevacuumsawaycarbondioxide;_ylt=Aq2B33uunTF25WgF1XQLbO_MWM0F

They mention the potential to use the CO2 with hydrogen to make hydrocarbon fuels, something we discussed here earlier.  The synthesis exists and will work, with a good energy supply such as p-B11 fusion, but I had doubts it would be practical to collect dilute CO2 from the atmosphere to do this.  But if the technology in the article is practical, it might work.

CO2 absorbents are nothing new.  I worked with a machine that analyzed carbon in steel by burning the steel, extracting the CO2 from the exhaust by an absorbent, then analyzing the quantity of CO2.

It is also possible to extract by cooling, and CO2 can be a byproduct of liquid oxygen and nitrogen production from air.  The going rate is something like a dollar a pound for dry ice at my local supplier, who also sells LN2 and LOX, but it probably could be done for a small fraction of that on a large scale.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 04:03 PM
CO2 levels are very low by geological standards. It stunts plant growth.

Want cheaper liquid/solid CO2? Buy a tanker load.

Despite what you have read in the papers the sun's increased output explains 80% of the recent temperature rise.

On top of that the alarmists have neglected to mention that man only accounts for 20% (at most) of CO2 rise.

We have had a 1 deg F rise. The sun accounts for .8 deg F. CO2 then accounts for at most .2 deg F.

Man mde CO2 accounts for 20% of the rise (at most). That would be .04 deg F. i.e. way down in the noise level.

The whole CO2 bit is a scam to separate you from your brains and your wallet. The first is pretty much accomplished. The second is in the pre-production stage.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 04:10 PM
Think of it this way - if you had a really really really good model of climate you might get within 1% of the real value. 1% of 300 deg. K is 3 deg K.  About 5.5 deg F.

Now add in that clouds/water vapor is not well modeled. The model handles chunks 150 miles on a side. Ocean circulation (the cause of the last few million years of ice ages) is not done well. Solar variations are not included.

It is all GIGO.

Think about it: we would kill for a IEC Fusion model that came within 50%. And the rules for a fusion system are way simpler and better known than climate rules.
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/03/2007 04:21 PM
Quote
M Simon - 3/5/2007  11:03 AM

CO2 levels are very low by geological standards. It stunts plant growth.

Want cheaper liquid/solid CO2? Buy a tanker load.

Despite what you have read in the papers the sun's increased output explains 80% of the recent temperature rise.

On top of that the alarmists have neglected to mention that man only accounts for 20% (at most) of CO2 rise.

We have had a 1 deg F rise. The sun accounts for .8 deg F. CO2 then accounts for at most .2 deg F.

Man mde CO2 accounts for 20% of the rise (at most). That would be .04 deg F. i.e. way down in the noise level.

The whole CO2 bit is a scam to separate you from your brains and your wallet. The first is pretty much accomplished. The second is in the pre-production stage.

At the risk of throwing us off topic, real references please... Especially the 20% of the Carbon spike.

To get us back on topic, a working fusion reactor could eliminate energy production process that generate acid rain, NOX's, and strip mining for coal.
Title: Re: Fusion with space related aspects thread
Post by: Crispy on 05/03/2007 04:39 PM
If man-made global warming is a scam, why was the idea started by scientists and has been forced onto those in power, kicking and scresamin?

But this is offtopic as you say, and besides, enough hot air has been generated already.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 04:53 PM
I personally think the Al Gore level of alarmism on global warming is unwarranted.

It definitely is real to some degree.

If it is real and serious, fusion is a very desirable solution on many levels.  But fusion is very desirable on enough other levels that it need not depend on global warming.  Among those possiblities is synthesis of fuels for transportation, for which there are other motives than reducing greenhouse gas emissions.

But with all the attention going to hare-brained schemes to reduce greenhouse gas emissions, I'd love it if that bunch would take a look at Dr. Bussard's reactor scheme and funnel a couple of million his way.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 07:43 PM
Why was global waring scare  started by scientists?

They need money.

Back in the 70s it was global cooling.

You know how it is. How much money can you get from "studying climate is interesting and possibly useful" vs "we are all going to die" ?

Which brings up a point about the Navy/Bussard Funding. I have had sceptics tell me it is just a funding scam. For all I know they may be right. I don't understand all the details well enough to be even reasonably sure (50/50) that it will work.  

I can tell you that even if the physics is sound the engineering work to be done is going to be immensely difficult in order to get the right trade offs.

There is a lot that will have to be found by experiments.

The idea of jumping from .001 watt to 100 MW in one jump is ludicrous from an engineering standpoint. I'd have no problem with some inflation at the beginning. The  step following .001 W  could be 100 W or even 1 KW.  At that level copper losses in the magnets will predominate  so reactor output will not be a very significant part of total power. Copper coils ought to be fine since they will have powers representative of  of what will have to be dissipated in a running reactor. Some of those problems can be solved (in at least a preliminary way) in the beginning.

From there on I'd scale at increments of about 2X in size (100X in power).

You might be able to pull it off in 5 years if you had the money to do overlaping development.  i.e. testing X, building Y, designing Z.  It is more like a 20 year project the way these things normally go.

Sadly no one is in a hurry on this who has the resources. We have a few hundred years of coal in the ground. Enough oil resources for at least 100 years. Enough nuclear for 100 years or more. So you know - what is the rush?

Scaring people with global warming doesn't seem like a sound policy if the science is not firm (it isn't). When the warming trend goes over to cooling (the reverse happened about 30 or 40 years ago)  people will feel scammed.

The advantages seem well enough established ( re: oil especially)  so that we do not have to base our campaign on dubious science.  If D-D can be made to work we will have a reactor that is no worse than nukes with a lot of advantages (neutron flux would be a lot higher due to about 2 Mev per fusion vs 200 Mev per fission). p-B11 would be nirvana.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 08:03 PM
all concentrations expressed in parts per billion)                   

Carbon Dioxide (CO2)                                                      

Pre-industrial baseline      288,000
Natural additions                68,520
Man-made additions           11,880
Total (ppb) Concentration 368,400               

From US DOE

http://mysite.verizon.net/mhieb/WVFossils/greenhouse_data.html

You have to scroll down to find the chart.

11880/(68520+11880) = about 15%, so 20% overstates the case.

If CO2 caused 100% of the 1 deg F rise then man is responsible for .15 deg F of that. If solar accounts for 80% then man is responsible for .03 deg F. We are all going to die. Send Al Gore your money at once to lift the global warming curse. it is a lot like the gypsy curse but more scientific. All the gypsy's have is bad vibes. Al has albedo.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 08:36 PM
Or how about the EPA?

http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/SHSU5BUM9T/$File/ghg_gwp.pdf

On the rate of CO2 increase:

Rate has fluctuated between 0.9 and 2.8 ppm per year for CO2 and between 0 and 0.013 ppm per year for CH4 over the period
1990 to 1999.

OK  are you going to tell me that man made CO2 output fluctuates by a factor of 3X over a decade? If not what causes the fluctuations? The climate change boys don't say.

The science is lousy and the politics is worse.

Middle East Oil (or Russian Oil) is a better reason to get fusion producing power.  And space travel - fast and economical.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/03/2007 08:46 PM
So, all the increase from 280 or so to the present value of around 375ppm occurred in the last 200 years or so.  What was the source of the "natural additions" to CO2 during this time that didn't occur during the previous several thousand years where CO2 concentration was pretty stable?
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/03/2007 08:47 PM
Quote
M Simon - 3/5/2007  2:36 PM
OK  are you going to tell me that man made CO2 output fluctuates by a factor of 3X over a decade? If not what causes the fluctuations? The climate change boys don't say.

Actually, they do.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/03/2007 08:48 PM
Quote
Crispy - 3/5/2007  12:39 PM

 enough hot air has been generated already.

Good point. The thread is about IEC fusion.

Quote
Tom Ligon - 3/5/2007  8:42 AM

FogerRox,

Cute!

The assembly of magnets you have illustrated with the field line show the wiffled condition.  


I got something right ! ! ! Cool.

Quote
Tom Ligon - 3/5/2007  8:42 AM

With no, or few, electons, the magnetic field extends more naturally on hyperbolic arcs to almost the center of the device.  Under that condition, the electrons orbit like the one you show.

With huge numbers of electrons, the field is pushed back as the animation illustrates.  This also chokes the cusps down to a smaller opening.  In that condition, one in a few thousand electrons escape to do the outer circulation, but the majority oscillate back and forth across the wiffleball volume.

The animation can't be run long enough to show electron lifetimes at a reasonable viewing speed, extimated at 100,000 transits.

I woke up and my first thought was that the field lines should initially extend to the center. SO once high #'s of electrons are injected, the cups close off, most electron flow is in the interior, inboard of the magnets?

Sans electron flow, this should be better:

http://i38.photobucket.com/albums/e101/FogerRox/singlemagnet6.jpg


Quote
kevin-rf - 3/5/2007  12:21 PM
To get us back on topic, a working fusion reactor could eliminate energy production process that generate acid rain, NOX's, and strip mining for coal.

Generally speaking a farm that has been fertilized for... say 40 yrs, the soil has a much higher Cat ion exchange capacity. Soil particles tend to take on the "N" fertilizer before plants can. IIRC Nitrogen is not water soluble at a PH of around PH 5.4-, so plants cannot take up appreciable quantities of "N". So a farmer puts down "N", it then rains (PH 5.6 to 4.8), washing the "N" into the soil where it bonds to the soil particle.

Most plant nutrients are water soluble between PH 5.4 to PH 7.0. Reducing sulfur & nitrogen (oxides?) emissions will reduce the need for high number's of #'s"N"/sq ft over the long term. Fusion generated electricity can/will provide many solutions to myriad problems.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 09:14 PM
I looked it up and you are right.

Man accounts for all the extra CO2.

Of course CO2 in geologic time has been 7X higher and steady, with temperatures falling while the CO2 was steady over the course of millions of years.

http://mysite.verizon.net/mhieb/WVFossils/Carboniferous_climate.html

So despite large natural CO2 sources,  man has "tipped the delecate balance" as one of the CO2 forcing articles put it.

I look forward to the return of global cooling. Then we can sell fusion reactors as ice melters and greenhouse warmers for food production. What ever happens fusion is the answer. It is almost as all purpose as CO2.

More so.  The CO2 folks have no answer for global cooling.

The CO2 boys are starting out at a scientific disadvantage . Their premise is: "Suppose CO2 accounts for all the temperature rise".  Suppose it doesn't? They are in big trouble if it doesn't or a cooling trend starts in 10 to 20 years as some scientists predict due to solar output declining (there is a 300 year cycle - not accounted for in IPCC models).

Just based on the disagreements here I'd say it was unwise to hitch fusion to CO2. I think oil replacement therapy has a bigger audience with fewer negatives.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 09:17 PM
FogerRox,

That one looks almost like mine.  You've got the idea.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/03/2007 11:21 PM
Quote
Tom Ligon - 3/5/2007  5:17 PM

FogerRox,

That one looks almost like mine.  You've got the idea.

And the new version of the wiffle state shows the field at the cusps far tighter when the fields get pushed back by the electrons.. Any text suggestions ?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 11:38 PM
Text suggestions?

Big type.   The resolution on these things is always appalling.  That means short comments, easy to read, and consequently simple.

When I got the comments back on the fact article, the editor was concerned because Wiffle Ball (tm) is a trademark, which he expects is vigorously defended.  Forms such as wiffleball or wiffle-ball are not so clearly covered, but the article now tiptoes around the whole issue.  But you might want to give a tip of the hat to the trademark holder, and mention that the resulting structure resembles their marvelous toy balls, if you use the term at all.

I can't speak for them, but if it were my product, I'd be happy to have people associate my product with something that saves the world, as long as I got proper credit.  Although I might sue if it flopped.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 11:46 PM
You are on fairly solid ground on the trade mark deal.

Wiffle Ball™  refers  to a plastic sphere with holes. Bussard's wiffle ball refers to a magnetic sphere with holes.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 11:50 PM
Field lines do not extend to the center even before the wiffle ball forms because the fields are opposing. At the center the field is zero.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/03/2007 11:53 PM
Yes, but they extend close to the center, as FogerRox's illustration now shows.  The result would be that low density plasma in the low field area would make a very pretty Christmas ornament, a bright ball at the center with graceful rays extending out the center of each cusp.

Once the wiffleball forms, the region greatly expands, becomes more spherical, and the cusp rays less pronounced.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/03/2007 11:56 PM
You can see something like that in some of the high speed photos of atomic explosions.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/04/2007 06:53 AM
This should be a bit better


http://www.youtube.com/watch?v=KLGxYpwy5MY
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/04/2007 09:04 AM
Very nice Fox Roger.

It really needs some music.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/04/2007 02:33 PM
Sweet!  I notice you show a few recirculating outside, but the text does not yet mention it.

Add some ions (radially in and out, inside the MaGrid, and some fusion flashes in the middle, and you're there!)
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/04/2007 03:21 PM
That was a really good animation.  Lots of effort went into that.

After the animation of the electrons is shown they could be replaced by a "probability distribution" of electrons, maybe represented by a color gradient, maybe pale red in the middle fading to white outside the reactor.  The ions could then be represented as individual blue dots.  Reactions could be represented by yellow flashes (again a primary color), with an arrow pointing to a helium ion outside the reactor.

Then zoom out.  Show the helium ions being funnelled through an electric generator, and stored or emitted through a magnetic nozzle.  The electric current generated could power relativistic electron beams that heat propellant on a big deep space probe.  Maybe a huge interferometer telescope array spanning the solar system, which would require an interplanetary propulsion system that would not waste fuel.

Oh yeah, going overboard here!  Actually the animation is just fine the way it is.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/04/2007 05:10 PM
Very nice, Rodger Fox.

That really shows what is going on.

If that was the first time I saw the concept, I would assume that with the cusps almost closed,
any electrons escaping through those cusps would be lost rather than being recirculated.

But that is a fabulous visual sequence.
Title: Re: Fusion with space related aspects thread
Post by: scienceguy on 05/04/2007 05:19 PM
Excellent video.

Could this method be used for confining antiprotons?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/04/2007 05:59 PM
Add some ions (radially in and out, inside the MaGrid, and some fusion flashes in the middle, and you're there!).

Make sure the ions are going really slow compared to the electrons. You might not want to slow it down as much as  a real physical representation would require (1/25th speed for 2.5Mev He4++ ions vs electrons). B11 ions would be even slower. Even with 200KV acceleration and a charge of +5 you are only up to 1 Mev of energy and the mass is almost 3X that of He4.

Given a 200 KV field to accelerate e- and the same for B11 (it will be less) I get the following

1 Mev B11 = speed of 1
2.5 Mev He4 = speed 0f 2.62
200 Kev e- = speed of 66.33

based on an electron mass at 1/2,000th the proton. All other masses integers.

For animation purposes a ratio of 1 to 2 to 4 might be good, B11:He4:e-.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/04/2007 06:06 PM
Uh, electrons are only lost when they hit something physical.  Circulation through the cusps and back is not a problem. With the higher magnetic fields at the cusps the odds of electrons circulating through them is smaller. They still circulate.
Title: Re: Fusion with space related aspects thread
Post by: braddock on 05/04/2007 06:38 PM
Quote
FogerRox - 4/5/2007  2:53 AM

This should be a bit better
http://www.youtube.com/watch?v=KLGxYpwy5MY

Nice schematic video!
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/04/2007 06:50 PM
ScienceGuy,

Electron lifetimes in this thing are estimated at 100,000 transits (at 12 keV), but that's on the order of less than a millisecond.  It would be far more effective confining low-energy electrons.

The field strength is intentionally too low to confine ions.  The ions are confined by electrostatic attraction by electrons.

To do antiprotons, you would have to confine positrons with the magnetic parts, and the antiprotons by the positron field.  So it might hold ionized anti-hydrogen for a while.  

The volume inside the magrid of WB6 was probably around 27,000 cc, and average density somewhere around 1e12 ions/cc.  2.7e16 antiprotons, at 1 gram per 6.023e23 particles, I'm getting around 4.5 e-8 grams.  I see a citation that a microgram of anti-hydrogen would have the energy equivalence of 20 kg of LOX/hydrogen, so that would give the equivalent of around 0.9 kg of the best chemical rocket fuel in common use.

Better than I would have guessed.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/04/2007 07:40 PM
Tom,

The faster a charged particle travels through a magnetic field the less it is deflected. If you double the mass of a particle and keep the energy the same you reduce the velocity by .707. Which says the impulse (F*t) would be 1.41X (because of the longer travel time with constant F). With a mass of 2X you get .707 the deflection (the acceleration with constant F is 1/2 because of the doubled mass) . For a given particle energy. So the deflection would be = sqrt ((M2/M1)*(E1/E2))  assuming a totally uniform field. Reality is going to be a little different.  However, it is in agreement with your point that the deflection of the ions is going to be less.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/04/2007 08:11 PM
MSimon,

Antiproton trapping is WAY out of the realm Polywells were designed for.  A lot of assumptions meant for high energy will be way off at low energy.  With my simpleminded crack at it using vague density estimates, I was expecting to not confine enough antimatter to power a bottle rocket.  In fact, the equivalent of two pounds of LOX/H2 would make a nifty little Bob Goddard Special.

Worth bringing back up if we ever get into the bulk antimatter business.

I once corresponded with a crazy rocket scientist who wanted to build a ship fueled with some kilotons of antimatter.  I requested he fuel the darned thing up somewhere the other side of Pluto's orbit.  He said that was overkill ... his calculations showed that outside the orbit of Mars was plenty safe enough.  "Safe as houses, as long as you do the right thing at the right time," he said.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/04/2007 08:15 PM
Quote
M Simon - 4/5/2007  5:04 AM

Very nice Fox Roger.

It really needs some music.

Led Zepplin? Kidding.. I have a microphone, I need to find that, to see if I can add narration.

Quote
Tom Ligon - 4/5/2007  10:33 AM

Sweet!  I notice you show a few recirculating outside, but the text does not yet mention it.

Add some ions (radially in and out, inside the MaGrid, and some fusion flashes in the middle, and you're there!)

Ions & text, right. And how/where are the ions introduced? (emitters)

Quote
BarryKirk - 4/5/2007  1:10 PM

Very nice, Roger Fox.

That really shows what is going on.

If that was the first time I saw the concept, I would assume that with the cusps almost closed,
any electrons escaping through those cusps would be lost rather than being recirculated.

But that is a fabulous visual sequence.

I'm not sure what you are saying, does the concept of electrons "pushing back" to nearly close the cusps not come across? Would a few close ups help?

On another note, Tom... when you speak in Texas, if you can secure a video of your talk... that can be posted on the net. Videos on the net are viral, you saw the result of the google tech talk. And that was too technical for many folk, something simpler will get a different/larger audience. Thats the idea behind my cartoon... IEC for dummies. Regardless, your talk in video form could be an asset.

My thoughts/concerns  sometimes go to "branding & marketing", using the viral nature of the net to help. Posting at boards and blogs is one thing, but incorporating video/media expands a blog posts' role/impact.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/04/2007 09:01 PM
FogerRox,

I don't know ISDC's policy on videotaping.  Possibly they do it themselves, or one of the participants may do it and offer a copy.  I don't have a very good camcorder (its analog, with a digital converter at home), but I'll take it and see what transpires.

I may want to use your animation, depending on how mine turns out and if I have time to do it.

WB6 introduced gas inside the magrid, most likely by directing a "molecular beam" of neutrals across one inner face (fancy term for shooting gas out a straight piece of pipe into a near vacuum, where the molecules just go in a straight line).  The actual start-up conditions of the device were set up to assure some cold electrons are initially present, and some of those should hang around close to the magrid.  Once ionization gets started, a significant population of cold electrons should build up there, without the energy to get further away from the magrid.  These just spin around the field lines looking for trouble.  The neutral beam should ionize readily.  If it needs any encouragement, microwaves tuned to create electron-cyclotron resonance at the field strength where ionization is desired will perk things up significantly.

I can envision fancier sources made with waveguides imbedded in the magrid inner surface, but that's way down the line.

I would just illustrate ions popping into existence from just inside the inner faces of the magrid, but outside the wiffleball boundary.  They will accelerate rapidly to the wiffleball boundary, which should act very much like the inner grid of a fusor.  Ions not creating fusion will mostly oscillate back and forth across the interior.  Some other collisions occur, which you can illustrate if you wish, but I don't know if it is worthwhile at the scale and intent of this animation.  A rigorous computer model would get into this.




Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/04/2007 10:15 PM
Tom,

IMHO, whats more important, is the bitrate and frame rate the file is saved at when compressing.  Not so much the camera. I "borrow" a "Super8" camera, feed the video thru a grabber, to my laptop, edit. I have gotten really good results with that "analog" camera... LOL.

If I can arrange for you do download the final version in a .wmv format, as a larger file.... would that be better? (Hmmm, in fact I maybe able to make it available as uncompressed video, that would support viewing in a much larger format.)
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/04/2007 10:30 PM
What I've been finding is a lot of analog cameras have half the resolution they ought to.  They will use 240 lines, or even 200, rather than 480.  It is particularly common in security cameras.

I've digitized pictures from this one at the max settings for picture quality, and it just can't touch even minimal digital quality.  It would be OK for small web videos, but there's no way folks will be able to make out the PowerPoint slides I'll be showing.

But the audio is fine.  I use Pinnacle (it crashes my computer a bunch but it does work eventually), and could cut between video and still slides, preserving voice.

Its gotta be better than Dr. Bussard's overhead transparencies.  I'll have to send him the presentation and a copy of PowerPoint for his birthday!

I've even got some of his transparencies from a talk I gave back in the late 90's.  I need to scan those in and make PowerPoint slides from them.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 01:27 AM
Maybe this is too simple a question, I don't know...

Electrons repel each other because they have like charges.  So, why would there be a high concentration of electrons *inside* the reactor?  Wouldn't the electrons prefer to build up *outside* after escaping through the cusps, and get trapped there instead?  If I assume that the electrons will follow the magnetic field lines, what exactly is causing them to concentrate inside the reactor?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 01:29 AM
The positive voltage on the magnetically shielded grid.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 01:38 AM
Ok.  So there is something basic about the Polywell that I don't understand.  The ring-shaped magnets are electromagnets, right?  I thought the direction of the current in the magnets would simply determine the direction the electrons followed the magnetic field lines.  Am I correct that the high voltage actually forces the electrons to circulate in one direction only?

I've seen animations where electrons or ions bounce back and forth in both directions.  I guess that's where my confusion comes from.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 01:48 AM
Once the electrons are in the central area (before Polywell formation) they travel strictly on inertia. Until the elctrons "clump" followed by the fuel ions "clumping" there is no electrostatic field in the center.

Note that the electrons don't really "clump". It is more like a density increase.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/05/2007 02:08 AM
Semper,

The Elmore Tuck Watson machine, without the magnetic field, is a simple vacuum tube diode.  The inner grid is the anode and accelerates the electrons.  In such a device, the electrons stop accelerating once inside the inner grid, and free drift across until they reach the other side of the grid, then decelerate out.   But they will not return to the outer walls or emitter ... they only want to get to that anode grid, for the same reason electrons do what they do in a vacuum tube diode.  The current is one-way to the anode, even if it takes a lot of passes to finally hit it.

Their ability to converge in the center is limited by their mutual repulsion (space charge).  The kinetic energy they acquire accelerating toward the grid is what allows them to concentrate at the center, forming a virtual cathode.  The height of the virtual cathode they can produce, if only electrons are present, is slightly less than the drive voltage between the electron emitters and the inner grid.

If ions are present within the inner grid, they are attracted to the virtual cathode, and then the ions form a virtual anode.  This reduces the braking problem the electrons experience (which is why bremsstrahlung radiation is not as severe as a couple of naysayers expect).  

The magnetic machine adds the complexity of the electrons following the magnetic field lines.  At low magnetic field strengths (the MPG machines, for example) the machine still works primarily by electrons moving in and out of the grid area.  Once you have a full magrid of the type of the WB6 machine, very high electron populations can do the diamagnetic repulsion of the magnetic field and form the wiffleball.  The wiffleball itself tends to act as a diode, trapping the electrons inside the magrid.  They maintain their kinetic energy quite well, bouncing off the inside of the magnetic field, but if they hit a hole, they can escape (once every few thousand transits).  But escape is temporary as the basic magrid recirculation is still in effect.

Eventually, if the trap were too effective, the electrons would lose kinetic energy and ability to maintain a deep potential well would fade.  Enough loss mechanisms remain, even in WB6, that this does not appear to be a serious problem.  The electrons are lost before losing much kinetic energy.  It might be possible to build one of these that was too good at trapping electrons, but I'm sure we could fix that.

The electrons can go either direction along a magnetic field line ... what changes with polarity is the direction of gyration around the field line.  This electron gyroradius is a function of the magnetic field strength and electron kinetic energy.  The reason the magnets must be spaced apart "several electron gyroradii" is to make sure they don't hit a surface when following a field line between magnets.  re = 2.38 Te^0.5 /B, for Te in electron volts and B in gauss, radius in cm.  For a 10 keV electron in a 2 kG field, I get 0.056 cm, or a spiral diameter of a little over a millimeter, and Dr. Bussard aims for about 8 gyroradii, which looks about right for the spacing on WB6.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/05/2007 02:19 AM
Quote
Tom Ligon - 4/5/2007  8:08 PM
If ions are present within the inner grid, they are attracted to the virtual cathode, and then the ions form a virtual anode.

Time for another stupid question.

Why don't the ions pick up electrons instead of shooting through the well and recirculating when they happen to miss each other or collide without fusing (which I gather is most of the time)?

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/05/2007 02:27 AM
It takes about 13 electron volts to knock an electron off a hydrogen molecule.  At 10 keV, they are desperately attracted to each other, but their kinetic energy is so high, they can't come even close to sticking.

Have you ever encountered people with that problem?

When one of these things is working right, the plasma emits very little light.  The reason is, ions emit light when they die, as the electrons drop back down the various energy levels and emit photons.  When the ions and electrons can't recombine, they're invisible.

The fireworks come when you let the gas levels get too high and the device lights off a Paschen discharge.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/05/2007 02:34 AM
LOL!  Got it!

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 02:40 AM
Ok.  That makes a bit more sense.  Physical electrodes (grids) are obvious and require no explanation.  I'm just not clear on how the magnets create a virtual anode, where electrons accumulate and result in a virtual cathode.  This means the vitual cathode and the virtual anode both occupy the same space.

Very wierd.  One has to assume sequential events to create this scenario, and that it isn't reversible.  Otherwise the system would be unstable, with the interior oscillating between states, alternately acting as anode or cathode.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/05/2007 03:14 AM
It is only stable because all the pieces are in vigorous constant motion, oscillating thru the middle of the machine.

I understood the fusor at first glance.  The Elmore Tuck Watson machine took only a little longer.  This beast I could understand as a magnetically insulated ETW machine, but the wiffleball is a mind-bender.

I never did really understand the closed box machines, with the magnets outside.  The thought was that the wiffleball effect could be made so good they did not require a magrid.  It was a seductive idea, but about a factor of 100 short of being workable.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/05/2007 05:49 AM
Version 3

http://www.youtube.com/watch?v=ydG3qPlUhNY
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 10:15 AM
I'd like to watch the end frames (with the ions) a little longer.

Plus - due to the electrostatic field most of the recirculation is going to go out and back through a given "hole" rather than circulating around the field lines.

What you get is a beam machine with a beam for every "hole". The beams from the big holes (center of the magnets) will be large. The beams from the cusps will be small.

It might be good (if possible) to show the magnets at a + voltage. And the outer walls at ground.

Ions are going to be concentrated in the center with few leaving that area. If they get outside the central area they will get slammed into the outer walls by the electrostatic fields.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/05/2007 03:31 PM
MSimon,

The ions pick up much of their kinetic energy between their birthplace near the interior surface of the magrid and the boundary of the wiffleball.  They will oscillate in that volume.  If one ever picks up enough energy to get past the bounds of this region, it will be lost to the outer walls.  That could happen with collisional upscattering.  That's why Dr. Bussard makes a point of describing the edge annealing collisional process that naturally almost completely re-equalizes the ion energy distribution at the edge.

Way too much detail for an animation of this sort.  Very necessary for a rigorous computer model.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 04:28 PM
I'm getting a different impression as to how this thing works.  Please correct me if I'm wrong, but my impression is that the electron guns supply the voltage (kinetic energy) so that the electrons can penetrate the cusps and get inside the wiffle-ball, and once inside they are trapped by the wiffleball-shaped magnetic field.  The electrons circulate within the interior.  If one follows a magnetic field line out a cusp it is lost.  It doesn't come back inside the reactor, it's gone forever.  But it might zip around *inside* the wiffle ball 100,000 times before escaping.  Is it possible that you guys are actually in error, thinking electrons can follow a field line out of the wiffle ball and then re-enter by the same means, or am I totally screwing this up?

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 04:32 PM
Semper,

You are leaving out the + charge on the magnetically shielded grid.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 04:40 PM
Ok, that would complement the electron gun, completing the circuit.  But that's all it does.  Right?  Once an electron has bounced around 100,000 times its lost so much kinetic energy that if it escapes it won't be pulled back in, even by the + charged magrid.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 05:10 PM
Particles are only lost when they hit something solid or combine.

The tough part is maintaining an energy inversion: most of the particles at a high energy state. Such an inversion is thermodynamically equivalent to a negative temperature.

Even tougher is keeping the energy states bunched, so the spread of energies is small.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 05:23 PM
Ok, but even if the electron isn't "lost" completely, once it escapes through a cusp it might not have enough energy to get back inside the wiffleball.  It might ride the field lines outside, reversing direction again and again, but always staying outside the reactor.  Once enough electrons escape, the charge outside the wiffleball might balance the charge inside, eliminating the potential well that the protons and B11 ions need to create fusion.  That is unless the "escaped" electrons are somehow dumped or grounded away from the reactor chamber.

Still wondering if I'm wrong here.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/05/2007 07:10 PM
Quote
Tom Ligon - 5/5/2007  11:31 AM....Way too much detail for an animation of this sort.

Agreed, the one hour documentary is not in the quay... I'm done.... LOL.

A recent google search led me to a page that talked about a mission to place a telescope at 550AU from the sun, to use the sun as a gravitational lense. IMHO  a fusion drive gives us the solar system & its resources. Oh the possibilities......

The only place I posted the link was at this forum. The second video got 67 views in 24 hrs. I guess some folks read this thread but don't post. I would ask that everyone send out the link to the video, email it, blog it, have at it.

http://www.youtube.com/watch?v=ydG3qPlUhNY
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 07:34 PM
The electrons are attracted back into the wiffle ball by the + charge on the magnetically shielded grid.

They will return to the central area with the velocity/energy they left with.

I am very fortunate to have grown up in the vacuum tube era. What we have here is a very large "beam power tube" where the "supressor grid" is a cloud of electrons. There are differences but the method of analysis is the same.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/05/2007 08:20 PM
I found this schedule:

http://selenianboondocks.blogspot.com/2007/05/isdc-tracks.html

Sunday - Mars & Beyond Day

Frontier Transport
A Realistic & ViablePath to LEO - Robert Talmadge
A Heavy Hauler to the Moon - Air Launch - Carleton L. Rhoades
Low Cost Propulsion Solutions: Commercial History of Liquids & Hybrids - Tim Pickins
Panel: Who Will Solve! (the cheap HLV Problem - Cargo CATS)
Basics of Orbital Mechanics - Seth Potter
Fusion Power/Fusion Drives (Bussard Tech) - Tom Ligon
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 08:32 PM
I think the + charge on the magrid is what initially creates sufficient potential for the electron gun to fire electrons into the wiffleball.  Instead of two concentric spherical grids with opposite charges, there are just electron guns and one grid that + charged.  The electron guns fire electrons at it.  The electrons miss the grid and pass into the interior where they are trapped by the spherical magnetic field.  Seems simple enough.

Once inside the reactor the electrons should lose energy via Bremmstrahlung radiation.  This energy loss keeps electrons from shooting out the other side of the wiffleball magnetic bottle and escaping, except in areas where there are small holes in the magnetic field.  The Wiffleball should be just as effective at keeping electrons out as keeping them in, so when an electron escapes through a hole (cusp) it should have a poor chance of returning, since it is lower energy than when it started.  Electrons newly emitted from the electron gun are at full energy, so they should be able to get past the pinching magnetic field lines and inside the reactor.  Once inside, it would be slowed by electrostatic repulsion of the electron cloud, but also retained by the wiffleball field, all the while bleeding energy via x-rays.  The accumulation of electrons inside the wiffleball creates a net negative charge there.

Fuel ions would be so strongly attracted by the net charge of the electrons and are so much heavier that they would virtually ignore the magnetic field.  They would be repeated attracted to the center where they would occasionally collide and fuse, producing high energy charged Helium ions.

If there is a contradiction here I'd like to know what it is.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 09:32 PM
An electron that gets "outside the grid" is then attracted by the grid until it passes the grid (assuming no collision).  Once "outside the grid" it is the same as an electron fired "at" the grid.

The electron gets slowed by the grid potential. It stops and reverses course. The energy it has passing the grid on the way in (towards the center) will be the same as the energy it had passing the grid on the way out (away from the center). It will have been accelerated because the vector has changed 180 deg.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/05/2007 09:45 PM
But the electrons are supposed to be trapped by the magnetic field, not simply allowed to "orbit" in and out of the grid.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/05/2007 10:02 PM
"But the electrons are supposed to be trapped by the magnetic field, not simply allowed to "orbit" in and out of the grid."

Sure. However, the beauty of the system is that electrons that escape come back. Most of them any way.

There is a lot of stuff going on all at once.

Just as escaping electrons are driven back into the system, escaping + ions are driven out. Which is why ion injection must be inside the grid.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/05/2007 10:13 PM
I loaded the final version of the video here, its a downloadable .wmv file: right click, select "save link as".

http://blip.tv/file/get/FogerRox-IECFusionForDummies350.wmv

This should embed the video:

                                                                           
A schematic representation of Dr Bussards WB6 fusion reactor, showing magnetic fields, electron & ion flow



EDIT: 56 views in 2 hrs, I'll take it.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/06/2007 12:26 AM
One minor quibble. Most recirculation is going to be in and out motion. Not much is going to follow the field lines around to the center of the magnet (or back to the cusps.).

BTW what is the code for embedding the animation?

I have a couple of places I want to post it as a clickable video.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/06/2007 12:28 AM
Suppose this technology turns out to be valid, and we go on and build lots of big stationary powerplants.  Then we aim to build a big spaceship.  Would this be the next big space project, like the ISS ?  How big would it be?  Fine if the reactor costs $200 million, but if it weighs in at a 10000 tonnes, it's going to be hard to justify the cost of launching it into orbit.  The launch cost would be $100 billion.  Can anyone estimate the weight and cost of launching a demo fusion reactor?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 12:42 AM
M Simon...
Embedding, go here
http://fogerrox.blip.tv/file/220118/

Click on "share" for coding options,

...or go to you tube, click to watch the video, and you will see a URL to embed, just copy & paste.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 01:27 AM
Semper,

I've got several of Dr. Bussard's papers on possible ship designs that I'm going to work into the presentation, but I'm still trying to digest them down to a more compact form.  He also does some economic projections estimating the costs of various colony efforts based on the ships.  The references are posted very early in this topic.  Do you have access to Journal of Propulsion and Power?

Give me a few days and I'll try to post what I've got.

Bottom line, if we can burn p-B11 a 100 mW to gigawatt levels, these things should easily be worth launching.  Compared to other nuclear electric designs, the cooling requirements should be less and they'll be better from the standpoint of mass if only due to the reduced radiator requirements.

But there is an awful lot of work to do and problems to overcome between WB6 and there.  Obviously.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 01:45 AM
Some interesting lecture materials here

http://fti.neep.wisc.edu/neep602/neep602.html

http://fti.neep.wisc.edu/~jfs/neep533_lect32_99_fusionProp.html

From Scandia, ALEGRA sim code

http://www.sandia.gov/capabilities/pulsed-power/prog_cap/codes/alegra.html
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/06/2007 02:53 AM
I guess the vacuum chamber wouldn't be needed in space.  That would reduce the weight significantly.  But a radiator for 20 MW of heat could be pretty big.  However the required radiator area varies inversely with the fourth power of the temperature.  Some of the electricity generated could be used to drive turbopumps that actively move heat out, and actually makes the radiators red hot and the reactor supercold, thus reducing the radiator size & mass requirement.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 03:29 AM
Semper,

I've always wondered how worthwhile heat pumping would be for increasing radiation.

The most extreme speculation I've seen was in David Brin's marvelous novel "Sundiver".  The story features manned ships entering and exploring the photosphere of the Sun.  This is made possible by a rather novel heat-pumped radiation scheme.  The heat is pumped into an x-ray laser that rids the ship of that pesky solar radiation.

I'm not volunteering for the first test.

One large radiator is better than 5 large radiators ... that's as far as I care to speculate.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 05:19 AM
Ahh David Brin, I read that one... years ago.  Read any Ben Bova recently?

After some proof reading here is a corrected version of the video:

http://www.youtube.com/v/U29NlGGaxOE
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 02:18 PM
OK, falling asleep last night, I was afraid that I'd done that.

30 cm, not 300.  Damn that decimal place.

300 is in sleep-deprived units.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/06/2007 06:38 PM
Semper,

Here is where you go wrong.

The Wiffleball should be just as effective at keeping electrons out as keeping them in, so when an electron escapes through a hole (cusp) it should have a poor chance of returning, since it is lower energy than when it started. Electrons newly emitted from the electron gun are at full energy, so they should be able to get past the pinching magnetic field lines and inside the reactor.

The Wiffle Ball as you say only keeps in electrons that are of a sufficiently low energy. However the main purpose of the wiffle ball is not confinement. It is to keep electrons from hitting the + grid. It does this by BENDING the trajectory of the electrons. The stronger the field the greater the bending force. In effect the electrons tend to get bunched where the field is weakest.

Since the density in the reactor is designed for few collisions, electrons will oscillate across the machine. From the electron guns, accelerated by the + grid. To inside the + grid which is "drift space (no velocity change). To outside the grid where the grid voltage decelerates the electron to velocity zero. And then the electron goes back into the system "as if it had been shot from an electron gun".
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/06/2007 06:40 PM
Foger Rox,

Had I remembered it was on Youtube I wouldn't have botherd you.

In any case your instructions will help those that need it.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/06/2007 06:51 PM
Can anyone estimate the weight and cost of launching a demo fusion reactor?

In my crude estimations I have used 25 to 50 tons for power plant weight.

I assume D-D fuel, using the neutrons produced to directly heat H2O reaction mass.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/06/2007 06:57 PM
Semper,

I guess the vacuum chamber wouldn't be needed in space. That would reduce the weight significantly. But a radiator for 20 MW of heat could be pretty big. However the required radiator area varies inversely with the fourth power of the temperature. Some of the electricity generated could be used to drive turbopumps that actively move heat out, and actually makes the radiators red hot and the reactor supercold, thus reducing the radiator size & mass requirement.

In space you might not need  100 MW for adequate thrust if the thrust was of long duration. If the cooling needs are modest a water tank might be adequate. Plus the exhaust would add to the thrust.

It is really hard to say anything difinitive since the actual requirements of a working reactor are almost total speculation at this point.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 07:08 PM
Quote
Tom Ligon - 6/5/2007  10:18 AM

30 cm, not 300.  

30cm, sounds like abut 1 foot
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 07:15 PM
I've spent part of the morning scanning figures from various of Dr. Bussard's viewgraphs and papers, relevant to the discussion of the topic at hand.  To get the desired resolution for my PowerPoint slides, these are running around 600 kB each, and one hits 1.5 MB.  I'm loathe to plop these casually on someone else's computer.

Of course, I remember finally getting a 40 MB hard drive and thinking it was a Wonderful Thing.

Anybody (i.e. FogerRox) care to post these in a place we can all hit?  I'll happily send them.  I have Dr. Bussard's enthusiastic permission to use the space-related material to promote the project.  I have a website set up, but lost the password years ago, and it does not have much storage space.

One pair of figures illustrate wiffleball formation.  One shows the wiffleball shape clearly, the other shows a morphing from a low-energy mag-mirror into the almost spherical wiffleball, viewed from inside.  That one visually examines the diode-like characteristic.  The mag-mirror involves roughly cone-shaped paths into the cusps, which an electron could no more miss than poured water could miss a funnel.  But the wiffleball interior looks like one of those plastic toy balls made by Wiffle Ball (tm), except with even smaller holes.  They're simply hard to hit.  Outside the magrid, the cusps are still funnels.  

In a funnel-shaped magnetic cusp, an electron will tighten its spiral as the funnel narrows and the field strength increases.  The spiral uses up some of the kinetic energy of the electron.  If it is all used up, the electron stops and mirrors back.  If it has sufficient kinetic energy to pass the choke point, it can escape.  Thus, the basic magrid interior magnetic structure will mag-mirror low-energy electrons, but will leak higher energies.  One means of creating the wiffleball is to start with low-energy electrons and ramp up.

Since electrons inside the wiffleball have no field lines to guide them, they're simply unlikely to find a hole.  If they do find a hole, they pick up field lines to follow and have no trouble getting back in.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 07:20 PM
FogerRox ... yep.  The WB6 magrid is actually fairly small. Dr. Bussard's NPO website shows a wide-angle shot of WB6 in the chamber, which is definitely 6 ft inside diameter (I designed the chamber, and probably still have the drawings).  Magnet diameters of about a foot, maybe a little more, are probably about right.

Actually, you may not need the dimension for your animation ... they all will work about the same.

The DD-burning net power demo machine would be about a 1.5 meter radius, or 3 meter diameter.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 09:50 PM
I also had to change the website url, somehow I had emc2.org.... not emc2fusion.org

Quote
Tom Ligon - 6/5/2007  3:15 PM


Anybody (i.e. FogerRox) care to post these in a place we can all hit?

 I get by with photobucket.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 10:29 PM
I did a little photometry on the WB6 installed picture.  Scaling to a 6 ft diameter on the chamber, the raw values are 1.36 ft OD, 0.85 ft ID, on the front magnet.  The real values will be just slightly smaller due to perspective.

Height of the side magnets should be about true, and measures 1.26 OD.
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/06/2007 10:54 PM
I think you meant photogrammetry.  ;-)
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/06/2007 11:29 PM
Whatever means measuring photos. I've measured light, too, but that's not what I was doing with the photo.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/06/2007 11:40 PM
Quote
Lee Jay - 6/5/2007  6:54 PM

I think you meant photogram.  ;-)

Thats like a telegram.... right  ?  ..... kidding....

Hopefully the last version of the video.... LOL

http://www.youtube.com/watch?v=MXyuN9nFka0
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/07/2007 07:13 AM
A new post up on the  IEC Fusion Yahoo News Group

http://tech.groups.yahoo.com/group/IEC_Fusion/

with a picture of the magnetic fields.

http://www.mare.ee/indrek/ephi/polywell_cube_bfield_log.png

Very nice.

BTW the News group is technical in orientation. We are all trying to get the physics of the Bussard machine down.

Simon
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/07/2007 08:28 PM
Stephen Wolfram's talk is interesting. It brought back memories, my Mom made a painting, 40 yrs ago, that was supposed to a a visual representation of a topic my Dad was working on, at the time. IIRC bifurcated differential equations. The painting looked like the antlers of a deer, simply antlers that constantly divided into to 2, going to infinity. I then thought of the simple ingredients of the first stars, stars that then nova'ed, creating the more complicated ingredients for the next generation of stars, etc. Which seems to be what Stephen Wolfram is saying.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/07/2007 09:12 PM
Back to an old cooling topic, we've been wondering how to prevent fusion product heat from cooking the inside surfaces of the magrid.

In order to sound intelligent when presenting Dr. Bussard's engine designs, I figured I'd better get the acronyms straight.  The QED/ARC engine is "Quiet Electric Discharge" (i.e. relativistic electron beam, the arc-jet from Hell) with All Regenerative Cooling (the reaction mass flow is used to remove waste heat, which only works for engines which use a fairly high flow of reaction mass, hence lower Isp but higher thrust).  

Looking up regenerative cooling gave the following:

http://en.wikipedia.org/wiki/Regenerative_cooling

... which states the following regarding the cooling of rocket motor combustion chamber walls: "The heat flow through the chamber wall is very high indeed, 1-20 MW/m2 is not uncommon."

The cooling systems described are corrigated steel coated with copper, or copper tubing.

Neat, how sometimes figuring out one problem figures out another!





Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/07/2007 09:53 PM
If more ISP and lower thrust is required.  The engine could be operated in a non-regenerative mode.

If water were used for cooling, the resulting steam could be used to operate turbines to generate power and recover some of the energy.  Then the steam could be run through radiators to recycle it for another go around.

Obviously, for this type of system, on a spaceship, the radiators would have to be huge and/or the reactor
would have to run at a lower power level than for regen cooling.

I seem to remember that the spaceship Discovery in the book 2001: A Space Odssey had massive radiators.

But that used fission reactors.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/07/2007 10:12 PM
That's the Controlled Space Radiation variant (QED/CSR).  It carries a small radiator.

Actually, it carries a LARGE radiator, but not when compared to the ship Bussard illustrates that is powered by a tokamak.  The one on the tokamak is about 5-6 times as large.  The tokamak is probably assumed to use some conventional thermodynamic cycle for conversion of heat to electricity.

You can play with the degree of regenerative cooling, and he has A and B variants of the CSR, for different mission lengths.  More radiator, more Isp, but more junk in the trunk.

Diluted Fusion Product is the lowest thrust, highest Isp variant.  He does not compare the radiators on that with the other two, but obviously it will have almost no regenerative cooling due to reaction mass flow so they would probably be somewhat larger than the CSR-B variant.  On the other hand, it does not use the REB heating of the reaction mass, so only the waste heat associated with the reactor and a diverter nozzle need to be removed.  On the DFP, you use the fusion products directly to produce thrust, and add some reaction mass so you can even tell anything is happening.  There were Vex values for pure fusion product posted here recently that gave nutty-high Isp values.

Comparing the Isp of the three

ARC     1.5e3 to 1e4 seconds
CSR     0.7e4 to 0.7e5 seconds
DFP      0.5e5 to 1.0e6 seconds
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/08/2007 01:52 AM
Quote
Tom Ligon - 7/5/2007  6:12 PM There were Vex values for pure fusion product posted here recently that gave nutty-high Isp values.

http://www.ibiblio.org/lunar/school/InterStellar/Explorer_Class/Bussard_Fusion_systems.HTML

QED Direct plasma thrusters
Fuel --> Exhaust
Power / Reaction
(f) Mass conversion fraction

Joules / kg
Exhaust speed  m/s
p + 11B --> 3 4He
8.68 MeV
1287
6.926 E13
11,800,000 m/s, something nutty like 400k mph, or Jupiter in 76 days, one way.
p + 6Li --> 4He + 3He
4.00 MeV
1645
5.472 E13


3He + 6Li --> 2 4He + p
16.0 MeV
704
1.277 E14

6Li + 6Li --> 3 4He

(Combined)
20.0 MeV
564
1.596 E14
17,800,000 m/s

3He + 3He --> 4He + 2 p
12.9 MeV
437
2.059 E14
20,300,000 M/s
De + 3He --> 4He + p
18.3  MeV
257
3.505 E14
26,500,000 m/s






Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/08/2007 02:27 AM
Nutty?  You call that nutty?  I'll show you nutty!

I'm in the middle of compiling some rocket performance data from Dr. Bussard's various papers on space applications of the p-B11 powered craft.

Before we start, it is important that you know that Dr. Bussard characterizes papers such as these numbers come from as "just for fun".  Mostly, the Navy did not care if he published them, as long as he didn't go into the reactor research.  The economic analyses involve some rough guesswork,  and are not something you would take to the Congressional Budget Office.

These include expected costs per kg of carrying payloads on various missions.  E/LEO is about $27/kg, LEO/Lunar surfae about $24/kg, and no, I did not forget a decimal place.  Mars was a few hundred per kilo ... still compiling that part.

From this he calculates costs to establish colonies on Luna, Mars, and Titan.

The calculations include the people, all their stuff (for Mars it was 50 tonnes per person, or about two semi trailer loads) and regular trips back to Earth.

4000 people on Luna, 1200 people on Mars, 400 people on Titan.  Each project around $10-20 billion (stuff extra but transportation thereof included).

Oh, stop laughing, guys!  The man is SERIOUS!  Yeah, he's talking about setting up a nice town on Mars for less than the cost of 4 Apollo moon landings.  Yes, he is talking getting to LEO for less than the price per kg they used to charge to fly the Concorde to Europe.

He's got numbers to back it up.  Kinda mushy numbers, granted, but the reactor is not built yet, either.

For darned sure there must be important stuff left out, but at least you get the general idea ... fusion is what we need to get where we wanna go.


Title: Re: Fusion with space related aspects thread
Post by: MKremer on 05/08/2007 03:04 AM
I don't think anyone will argue that fusion will be best, but I also think very few people would agree to hold off on any type of manned missions until fusion technology (and its associated plant engineering/production technologies/reliabilities) is to at least where our current fission plant technologies are now.

So, unless there's some really big engineering breakthroughs in efficient fusion plant design (not to mention just getting to that point in the first place, and small enough and economically enough to be effective), I think we'll have to design and depend on fission-powered technologies for maybe at least the next 20 years or more.

That's being generous for a timeline that efficient fusion plant technology is solid within the next 5-8 years, and considering it would require 3-5 years, minimum, to design/budget missions using the technologies available at the final design/budget committment, plus an additional 3-6 years for construction/testing/possible additional delaying budget limitations and technical resolutions/changes redesigns/rebuilds/retests before any launch, including 2-6 month pre-launch preps/integration/final testing/launch could take place.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/08/2007 03:30 AM
MKremer,

Have you followed this thread from the beginning (its only 400-500 posts), and read the referenced material?  This may very well be that breakthru.

It is the most promising fusion program I've ever seen.  It has had some success in the lab, but it definitely needs to prove it can work continuously and be scaled up to net power, and burn the fuel of choice.  Yes, it has a way to go.  But the means of making fusion Dr. Bussard has been working on for a couple of decades is the most straightforward and sensible of the bunch, and well suited to space applications if it works.

And Bussard is the guy who came up with fission rockets (he set up Rover and designed Kiwi A).

If I had to go to Mars in three years, I'd recommend getting NERVA out of mothballs.  But to set up a Mars colony in 20 years, this is the technology we want to start developing now.

Will you be at ISDC?  I'm giving a talk.
Title: Re: Fusion with space related aspects thread
Post by: MKremer on 05/08/2007 03:47 AM
Ah, no, haven't even thought about it... just trying to keep up with current research/technologies in 100's of areas is hard enough for just one of many overall interests, especially for someone on the sidelines. :)

Perhaps I'm jaded - I've been reading things for many years (since the 60's) about the reports of fusion promises, 'breakthroughs', and even predictions of genuine production power plants, for a long long time. Almost every "promise" has been sometime within the next 10-20 years from the time it was stated. And every one of them hasn't come to pass, for whatever technological/physics-limited/budgetary reason.

So, sorry, yes I'm rather cynical now even about 'enthusiastic' research and new direction reports that the solution is "just around the corner!"
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/08/2007 03:50 AM
Exactly.  I'd be skeptical myself if I had not worked on the project for over 5 years. If you were not skeptical, you'd be gullible.

The approach is a highly advanced version of the basic idea of the Farnsworth fusor, the simplest and most direct of fusion machines. The idea is to use high voltage rather than heat to achieve the ion velocity needed for fusion.  It is based on straightforward physics.
Title: Re: Fusion with space related aspects thread
Post by: MKremer on 05/08/2007 04:12 AM
Let's hope it proves itself (and I really do hope it proves itself both physically and economically).

Even through the all the history of promises and "hype" I still can't imagine that we don't know enough by now about so many fusion process theories that someone still hasn't been able to engineer *something* that finally works well enough to be power-positive and design into a product with commercial/scientific profitable results.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/08/2007 04:34 AM
Quote
Tom Ligon - 7/5/2007  11:50 PM
  It is based on straightforward physics.
In a way, its so simple. Beautifully so.

Quote
MKremer - 7/5/2007  11:47 P

PMerhaps I'm jaded - I've been reading things for many years (since the 60's) about the reports of fusion promises, 'breakthroughs', and even predictions of genuine production power plants, for a long long time.

IIRC I 1st read about Tokamaks around 1979 or so, the Torus or toridial angle has not yet paid off. I have to to talk to my Dad, a retired Math PHD. I wonder if he is aware of the current IEC angle.

Did someone say "NUTTY"?

Photo Sharing and Video Hosting at Photobucket Photo Sharing and Video Hosting at Photobucket Photo Sharing and Video Hosting at Photobucket  

OK, lets lean to the serious side:

Photo Sharing and Video Hosting at Photobucket


Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/08/2007 07:48 AM
Tom says:

Will you be at ISDC? I'm giving a talk.

I think it is important that you suggest at the end of your talk that people contact their Congress critters and see if we can't get them to get the Navy contract funded/finished.
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/08/2007 01:37 PM
Or give it a new budget under all these 'alternate energy' intiatives :) I would like to see one of these attached to the power grid in a positive way :)

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/08/2007 02:55 PM
Just a reminder, I'm scheduled to be interviewed on "The Space Show" tonight, at 10 EDT, 7 PDT.

Dr. Livingston has a family emergency working in the background, so it is possible the interview will be postponed, but for now it is still on.

http://www.thespaceshow.com/newsletterfinal.htm
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/08/2007 11:16 PM
Tom,

I got an e-mail today at NOON from David Livingston. You are definitely ON for tonight at 7 pm PDT. I hope to God that some of the people that post here listen in. I will!
Title: Re: Fusion with space related aspects thread
Post by: braddock on 05/08/2007 11:58 PM
The show can be listened to live over the internet via http://www.thespaceshow.com/live.htm
Good luck tonight.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 12:38 AM
Pimpin

http://www.dailykos.com/story/2007/5/8/181517/3478#c5

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x848625
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 12:50 AM
Pirate!  FogerRox, that photo lives on The SETI League's website.  Whoever posted the photo of me at Philcon on the DemocraticUnderground site was supposed to check out the "fair use policy".  http://www.setileague.org/press/photouse.htm

Please give them credit.  Dr. SETI was very helpful to me on my last story!

It really does a science fiction author's street cred wonders to have their photo posted in conjunction with a Search For Extraterrestrial Intelligence.  The full story of why it was posted can be found by scrolling down to  6 March 99, then reading the blips for the following two weeks,  at http://www.setileague.org/photos/pixwk99.htm

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 01:16 AM
Servers down @ DU, I've been tryin... to edit.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 02:15 AM
"We own the solar system"


I love it.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 02:18 AM
Tom is on now.

Good so far. A short history of Dr. Bussards early post WW2 work.

Heat transfer and fluid flow was Dr. Bussards entry into the business. Very important stuff.
Title: Re: Fusion with space related aspects thread
Post by: coach on 05/09/2007 02:55 AM
Suprise!!!

Dr. Bussard has just called in.  


Coach
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 02:57 AM
Coach.

Yeah!
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 03:02 AM
Quote
coach - 8/5/2007  10:55 PM

Suprise!!!

Dr. Bussard has just called in.  


Coach

Sweet ! ! !
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 03:28 AM
You know, Bussard is as sharp as a tack.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 03:38 AM
Well done Tom!

A thrill to hear Dr. Bussard
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/09/2007 03:39 AM
Have to agree!  Bravo!  Good show!
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 03:41 AM
Cubic Magnetic field image.

Explanatiion

http://www.classicalvalues.com/archives/2007/05/fusion_image.html
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 03:42 AM
Lets see if I can get it this time.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 03:57 AM
Can I get that in stained glass?

Simply gorgeous!
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 04:08 AM
I posted it at a couple of places as art.

My first mate who is an artist loved it! She saw it on the screen and asked who did it.

The scale is logrithmic with about 1.433 per step. 32 steps a ratio of 100,000 to 1. Which roughly covers from Earth's magnetic field to around 10,000 gauss or 1 Tesla.

It really shows no field in the center.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 04:09 AM
No relationship to.....


width=270
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 04:12 AM
This is a simulation of the magnetic field in the WB-6 Bussard Fusion Reactor. A picture of the WB-6 can be found here.

It was done by Indrek. He posted it to the IEC Fusion Newsgroup. His simulation is logarithmic with 32 steps. Each step is 1.433 times the size of the previous step. It represents a field range of about 100,000 to 1. You can contact him through the newsgroup.

It was calculated using a program designed by Indrek using the Biot-Savart Law.

Not that it will matter to most folks.

It is a pretty picture.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 04:15 AM
Interestingly enough I went to Dead Shows pretty regularly from about '67 on.

Thanks!
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 04:25 AM
MSimon,

But can you make it simulate a wiffleball? Is there a way of introducing a strongly diamagnetic sphere into the device.

I'm going to get brave and try to attach a wiffleball.  Let's see what this "Attach a file after posting" box does ...

Ah, it works.  These figures are from an earlier inside report, but were used as Figure 16 in the Valencia report, so I know they're OK to use.  These are actually readable.  The upper one clearly shows where the phenomenon gets the name, and the lower one shows the development from the basic structure you guys have been modeling, with mag-mirror intermediate steps.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/09/2007 05:14 AM
Why not join us at the IEC Fusion group and ask Indrek yourself?





Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 06:40 AM
Quote
M Simon - 9/5/2007  1:14 AM

Why not join us at the IEC Fusion group and ask Indrek yourself?

Good idea, creating artwork helps out. Viral media.. ya know... Might be able to make some good slides for Tom When he speaks at Dallas.





Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/09/2007 12:59 PM
Missed the space show last night.  I had family obligations.  I'll have to see a rerun.

Anyway, I was looking at a photo of WB-6 and it got me to thinking (Always a dangerous thing).

The 6 coils in WB-6 seem to be touching which makes sense.  I'm sure that at least one of the coils needs
to be mechanically attached somehow to the outside.  Could it be suspended by a cable from the top of the
vacuum chamber?

Does the fact that the coils are in contact with each other cause a problem?  Would that be a place where
recirculating electrons could touch a solid surface and therefore be lost?

If so, what would be the best way to minimize these contact points?

Would spacing the magnet coils slightly and then attaching each coil to the outside work better.

What about, having thin cables that would attach the magnet coils to the outside and then attaching the coils to each other.  The whole system would be under tension.

Just a thought.
Title: Re: Fusion with space related aspects thread
Post by: Owen on 05/09/2007 02:16 PM
They don't have it listed on the space show site yet, but the recording is online
http://archived.thespaceshow.com/shows/709-BWB-2007-05-08.mp3
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 02:45 PM
BarryKirk,

The 6 coils of WB6 are spaced apart, although they do attach by a small cylindrical projection, which will carry electrical interconnections and which hold the assembly together.  This projection is in an electron path, and almost certainly represents a loss mechanism.  It is evidently a vast improvement over the old configuration where the coils touch, but still not perfect.

WB6 was supported from the bottom by four big ceramic insulators.  It would be interesting to investigate the possibility of supporting each coil independently by 3 or 4 similar insulators projecting from outside the Faraday cage that represents the electrical outer boundary of the device.  This would allow more effective cooling of the magnets individually (in larger machines where cooling is used), and should eliminate the loss path.  The insulators would be in a region of recirculating electrons, but at low density (probably about 0.01% of the density inside the magrid).
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/09/2007 04:32 PM
That 0.01% still sounds large.  I seem to remember hearing that if the electron losses are over
1E-04 or 1E-05, that would kill the machine.

That is why I suggested cables or wire under tension.  To reduce the cross section of physical material that
might be in the flow path of the electrons.

There are probably more optimal configurations than even that could reduce the lose mechanisms even more.

Is it possible to magnetically shield the mechanical supports to further reduce losses?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 04:47 PM
The 0.01% is not a loss.  One electron in a few thousand escapes the wiffleball via holes, but the magrid recirculation brings the electrons back in.  Considering the escapees are in a larger volume than the wiffleball, I estimated that the density in the paths outside the magrid is probably very roughly 1/10000 of the density inside.  Most of the electrons doing the magrid recirculation leave the faces and corners, and will come nowhere near the connections. Some of the few that slip between the coils may strike the cylindrical connection.

As much improved as WB6 is over previous models, I would not be surprised if eliminating even this small loss area could improve electron lifetimes by an order of magnitude.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 05:59 PM
Vital Electric Fusion: Proven, Safe, Cheap

Energy device in funding limbo for two decades -- dying on the vine for lack of nuclear weapons potential.



by Ed Ward, MD
Edited by Sterling D. Allan

US Physicist Dr. Robert W. Bussard has produced proven, consistent, working prototypes of a fusion device that does not need to release neutrons as part of the fusion process.

Neutrons induce radioactivity to their immediate surroundings.  Bussard's method does not do this.

This just one of the major drawbacks of other fusion projects such as the Tokamak project. The massive (30 meters X 110 feet) Tokamak/ITER project (D-T/Deuterium - Tritium) fusion reaction produces about 20 million units of energy mostly in the deadly neutron (neutral charge) production and requires gravitational strength containment/compression.

In contrast, Bussard's Inertial Electrostatic Confinement (IEC) Fusion reaction produces about 10 million units of energy per reaction, requires much weaker electric forces/fields for confinement of the reaction and is only about 2% of the size (about 15 X 12 feet) of the Tokamak reactor.

Rest of article

http://pesn.com/2007/05/09/9500470_Electric_Fusion/
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 07:19 PM
Hmmm, the first paragraph rather over-states the facts.  Dr. Bussard has proven repeatable, brief DD fusion, made evident by a whole bunch of neutrons making a few neutron counts.   He expects that the method can be scaled up to net power, and will be able to use a fuel that does not produce neutrons.

But they are enthusiastic.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 08:01 PM
Yes, they seem to not have bits out of place, but are enthusiastic. I didn't think the article comes from an experienced/polished writer either.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/09/2007 08:48 PM
Tom,

Great job last night! 232 bucks per kilo to Mars is an amazing number!
Doc Bussard mentioned that he did a presentation at YAHOO. Does anyone know of a video link for that talk? Also does anyone know how to contact Doctor Nicholas Krall? Or is it Krallich? It would nice to get ALL the lab assistants and theoreticians that have worked on the project talking here about the work. Is Doc Bussard married to the female president of ECM^2?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 09:12 PM
Quote
Tony Rusi - 9/5/2007  4:48 PM
Does anyone know of a video link for that talk?

Nada, zippo, nutin

http://video.yahoo.com/video/search?p=bussard+IEC+fusion&ei=UTF-8&x=22&y=15
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 09:18 PM
Tony,  

If that fancy fusion aerospace plane can be made to work, surface to LEO for about $27 per kilo, then the lunar transport/lander could fly you to the Moon for another $24/kilo.  Imagine the boost to the space tourism industry.  We'd actually be making reservations instead of hoping some rich relative would buy us a trip.

The trip to Mars is priced below what now would be pipe-dream cheap for just LEO.

The economic boost is not just fuel, although a couple of pounds of boron and some water are pretty cheap.  Its the incredible payload fractions, short trip times, and projected 10-year amortization of the craft over many flights that are the really big difference from the usual way of doing business.  And each fusion-powered element improves the economy of the rest.  The aerospace plane makes all the launch to LEO costs almost trivial, all the rest give a reason to be built.

The official explanation for why his wife is the company president is, she is the only person on Earth who can make R. W. Bussard do what he needs to do when he doesn't want to do it.   Great lady, classy, smart, and organized.

I got a communication back from Dick King at Yahoo, the fellow who contacted me to see if Dr. Bussard would be interested.  The talk did occur, but is posted only on the Yahoo intranet.  I've let him know everyone is interested.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/09/2007 11:28 PM
Quote
Tom Ligon - 9/5/2007  5:18 PM  I've let him know everyone is interested.

Doesn't he know its his civic duty, if there is Video, to let the world know,,,,,, gheese, the dude is Sooooo Lame.....

Seriously, the fun I could have with some Good Doc Bussard footage, w/diagrams.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/09/2007 11:43 PM
I personally think we ought to all chip in and buy Dr. Bussard a copy of PowerPoint.

He can have my presentation when I'm done, which will probably have your animation and MSimon's stained glass, the pictures from the SETI League, and all the stuff I've been scanning out of his older papers that came out so poorly in the Valencia report.

I'm picking the best of them (like those wiffleball pictures) and using Paint to clean up the crud where they've been photocopied too many times on a dirty copier.  Then I use a picture manager to straighten them back out when they were photocopied crooked.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 12:19 AM
Quote
Tom Ligon - 9/5/2007  7:43 PM

I personally think we ought to all chip in and buy Dr. Bussard a copy of PowerPoint.

Nah... http://www.openoffice.org/

Replaces Word, excel, powerpoint. for free. I've been using it on my new laptop since late last year, all my geek friends recommended it. ANd I was too cheap to pay for MS word, PP, & Excel, 100% compatibility too.

I used it to generate this 3d lettering

http://www.youtube.com/watch?v=lR1x2HoeyPM
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 01:32 AM
That politician obviously spent far too much money on that ad!  Too much for a township.  Probably has funding from some cartel of the very rich! ;-)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 02:17 AM
Tom,

I'm only the co-ordinator.

Be sure to give Indrek the credit. If you want to give me a plug - boost the IEC Fusion news group.  We are looking for technologists, plasma physicists, and any one who wants to learn that kind of stuff.

IEC Fusion news group

http://tech.groups.yahoo.com/group/IEC_Fusion/

http://tech.groups.yahoo.com/group/IEC_Fusion/

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 02:29 AM
Tom, check your email I found some graphics that might be useful, including a much better version of that wiffleball graphic.
Title: Re: Fusion with space related aspects thread
Post by: Jorge on 05/10/2007 02:59 AM
Quote
FogerRox - 9/5/2007  7:19 PM

Quote
Tom Ligon - 9/5/2007  7:43 PM

I personally think we ought to all chip in and buy Dr. Bussard a copy of PowerPoint.

Nah... http://www.openoffice.org/

Replaces Word, excel, powerpoint. for free. I've been using it on my new laptop since late last year, all my geek friends recommended it. ANd I was too cheap to pay for MS word, PP, & Excel, 100% compatibility too.

100% compatibility on whose planet? I've yet to see OpenOffice successfully open an MS Office file with even the simplest macro embedded.
--
JRF
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 03:39 AM
Anybody got an account here ?

http://www.freerepublic.com/focus/f-chat/1830767/posts
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 03:55 AM
Tom:

I'd like to make a contribution here somehow.  I heard Dr. Bussard say during the Space Show that he currently has no money.  Don't take this personally after all your efforts, but I haven't donated any money myself.  Believe me it's not for a lack of interest.  There are a few obvious reasons why people might not be donating money to this cause:

1.  There is no ticker, or other "thermometer" on his EMC2 website showing how much money he has already received.  There are alot of people in this world who only go with the flow.  When lottery jackpots get REALLY big everyone-and-his-monkey's-uncle runs out and buys a ticket.  An indication of cash flowing is really beneficial in that way.  People need to see how others are contributing before they lift a finger.  When Bussard tells people that he's received no donations, it might actually hurt his cause.  It makes people standoffish.  Nobody wants to be the first to donate, the first to stick out his neck.  Even panhandlers put a few coins in their cup and shake it when people walk past.  Apparently it works.

2.  We get nothing in return for our donation.  I know it's non-profit but Bussard is somewhat interested in getting venture capital.  My donation would essentially disappear and I wouldn't get any news of how it made a difference, and without any "short-term" payoff, even a symbolic one, I just don't take out my credit card.  Things I've bought over the internet however include mail-order books, t-shirts, and e-books.  The latter is interesting because some very odd literature can seem interesting in electronic format.  I did some elementary research on carbon nanotubes, specifically how to get around the difficulty of fabricating long nanotubes by using weaves.  There is a machine that has been around for ages that can mass-produce & assemble ring-maille into continuous sheets, and the description was only available in e-book format.  There we animations and layers to the description.  My idea was to create a nano-sized maille factory that turned short nanotubes into ring-maille.  I lacked the research funding, and the interest in the nanotech research establishment seems entrenched in electronic applications and nobody was interested in funding my idea.  But my point is, I SPENT MONEY, something like $15, on an e-book that described how some obscure machine worked, how the components went together, etc.  And for no other purpose than to see if it would be useful.  If Bussard made such a document available for a small donation, people would probably snap it up.

3.  Other researchers are doing these things, making merchandise available, such as Focus Fusion, such as any other charitable organization.  People expect it.  Even if it is a waste of time, people want to be entertained by the stereotype "storefront facade".  It makes people feel comfortable with the idea, less nervous.  At the moment, Bussard is doing great in every way but.

4.  Sometimes professional organizations rely on membership dues to put out newsletters & magazines, establish professional standards, to maintain websites & offices, and even to fight legal battles.  They are also non-profit organizations.  If engineering associations didn't collect dues from licensed engineers there would be no money to prosecute people who did engineering work without licenses.

5.  Corporations sell shares to raise capital.  Look how much money Google raised when they went public.  And as the shares gain value, the shareholders get a return on their investment.  And even companies that are considered very high risk often raise substantial capital.  I believe they are traded on yellow sheets, or something (I'm not a stockbroker).  There are countless risktakers in this world that will throw money away if there is a one-in-a-billion chance of getting rich.  Believe me.  Lotteries are a perfect example.

6.  Speaking of lotteries.  I believe there is a cancer research society that holds lotteries.  The jackpot grows as people donate.  The jackpot is some fraction of the total donations.  Some of the money goes into the jackpot, some goes into research.  That's how it works.  Their jackpots are HUGE.

7.  Bussard should name a successor.  He is getting on in years, and people might think if he gets sick then the research will just stop.  After that there would be no payoff, no return on their investment.  The corporate model is good because there is a controlling group rather than an individual.  Continuity is guaranteed that way.  Right now, continuity is not guaranteed.  Are Hirsch or Farnsworth still alive?  There must be people that would serve on the "Board" of his research company.

8.  The internet is a bottomless pit of information.  People who frequent message boards like this one expect to get information for free.  They dig and search, and eventually they find what they are looking for.  If they can't, they debate with people like yourself, Tom, to try to tease out a few key details to round out their understanding.  All without spending a penny.  I'm the worst example, cause I can find anything on the internet.  Exceptions only include reference-type information:  formulas especially; tabulated data is also hard to find online; whole scientific papers (not just abstracts) are hard to find as are the papers listed in their references;  solved textbook-style problems...  These are things you can attach a price to.

I don't know if this is helpful.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 04:09 AM
2. We get nothing in return for our donation.

Cafe' Press is easy if you have some artwork. Send me an e-mail or leave a post here and Ill be glad to help.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/10/2007 05:23 AM
New York Citi today announced that it will direct $50 billion over the next 10 years to address global climate change through investments, financings and related activities to support the commercialization and growth of alternative energy and clean technology among the clients and markets it serves, as well as within its own businesses and operations.
http://www.nieuwsbank.nl/en/2007/05/08/t015.htm

This is topping Bank of America's $20 billion bid.

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 05:42 AM
More like a powerpoint:

http://www.youtube.com/watch?v=rBfsq80EgOs
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 03:01 PM
Semper,

I hear you.

I'll at least get a t-shirt for being on "The Space Show".

The EMC2Fusion.org website is better now than when it first appeared, but it has a long way to go to match Focus Fusion.  Dr. Bussard is multi-talented, but he is no webmaster, and will need help to do what you suggest.  There have been some folks who have offered to dress it up.  He probably did not consider that a priority early on, but as he has shifted focus to the NPO, it should be a higher priority now.

This might be right up his wife's alley, though.  She is the sort you might expect to see involved raising funds for PBS or an arts group, where premiums are often offered.  With your permission, I'll forward your post to her via Dr. Bussard.

My thinking as of a month or so ago was to donate this year's writing income to the NPO, since both my story and article were inspired by Dr. Bussard.  But then he asked me to go to ISDC.  The airfare alone will use the proceeds from the fact article, and the conference fee, NSS membership, hotel, meals, shipping, photos, and printing will probably eat up the novella check.  I should at least be able to write the costs off against writing income.  And I don't even get a t-shirt!

Consequently, I've not made a donation either, so you guys have gotten further into the machinery than I have.

But I was figuring I'd not raid the cookie jar and invest a little lump of cash sitting in my stock accounts, on the off chance I'd be invited to join a VC group.  If I donated that sum to the NPO, I'd miss my opportunity to roll the dice.  I personally rate the odds as better than Vegas, and more fun.

As he says he still has two investment groups on the line, I may stick with that vain hope a little longer myself.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 03:07 PM
Pbelter,

Thanks.  I am forwarding that to Dr. Bussard.

Tom
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 03:29 PM
Semper,

Farnsworth is long gone, but Dr. Hirsch is alive and well, and may be on an advisory board to EMC2_FDC.  I believe Dr. Krall is also still involved (he is the most knowledgable regarding theory, but has to be dragged kicking and screaming into a lab).  There are at least a few other IEC fusion researchers who have had various degrees of friendly association of one form or another.

Obviously, from the show, Dr. Bussard's age is a concern to many people.  I'd be willing to wager that chief among them is Dr. Bussard.  I don't know what, if any, arrangements he has made for a successor, but I am quite certain it is something he has thought about.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 03:59 PM
Tom:

Sure, you can send my post to Dr. Bussard or his wife.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/10/2007 04:26 PM
That's good to hear that their are two investment groups potentially interested.

I wouldn't ask who they are, they probably want to remain annonomous until an announcement on their terms.

But, any idea if either or both of these groups are serious?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 05:08 PM
I wouldn't KNOW who they are.  One can speculate that Jim Benson is involved with one group, but I don't even really know that much.

What Dr. Bussard said on "The Space Show" suggests there are two groups interested, but Dr. Bussard was not happy with "the terms".  You guys had some reservations about private funding meaning excessive control by a single group in early discussions here ... evidently Bussard does as well.  He mentioned he'd put it in the public domain, if necessary, rather than simply turn it over to a group whose sole goal was to own it to get rich.  He does seem concerned that the terms include promoting public good in addition to getting rich.

But having two groups interested opens the possibility of some competition and negotiation to achieve those terms.  So who knows?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 05:24 PM
Get rich. Is what investors try to do.

If the Dr. is not in alignment with that he ain't going to get  the money.

Patents only last 20 years. Countries can steal the technology (once it is out there). Right now there isn't even  anything to steal.

Giving it away is the best way to delay the project indefinitely.

==

Profit is not a dirty word. Huge profits are not bad. The only way the profits can be huge is if the technology lowers costs well below what we currently do.




Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 05:41 PM
Dr. Bussard is already nearly 80 years old.  His EMC2 website states it will take 1.5 - 2 years to build and validate WB7 and WB8, but only after he raises the money.  It will take another 5 years to build a 100 MW demo powerplant, but again only after he raises the money.  Fundraising has already delayed research by over a year.  There are many researchers who continue working past age 65, but I don't think we should be under any illusions that Dr. Bussard will be able to continue for another 10-15 years to see the Demo plant through.  Even if he lives to 100, he may be in no condition to keep working.  He may already be one of the oldest living scientists.  Maybe he could sign an agreement with someone he knows that all the development rights go to him, or fall under a partnership business, should his health fail or should he not be able to continue.  It would be a fail-safe for people who want to donate, but are afraid research will not continue.

Also, if he is willing to give the technology to anyone, even the Chinese, why not agree to proprietary terms so that a VC group can develop it?  There would seem to be only a thin distinction between those two choices.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 06:15 PM
The mind fairly swirls at the possibilities, pros, and cons of all the approaches.  I was the one arguing that to attract private capital, you don't want to do anything to the deal that made it unprofitable.  Giving too much away would do that, which, according to what he said on the show, is why he has not yet published all the math and computer models that make it work.

There are some stock funds that specialize in "green" stocks.  Looking at that post earlier from pbelter about New York Citi aiming $50B at investments that address global warming, I wonder if they, or some "green" VC group, might be willing to address such "terms".  I don't know what those terms are, but it does sound as if Dr. Bussard may be insisting on assuring some fairly equitable distribution of the technology worldwide.  Possibly this could be done by some means other than investor altruism ... set up a government or world fund to spread the gadgets around once they are developed, in cooperation with the investors (who would make money on the deal).
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/10/2007 06:48 PM
I think the best approach for Doc Bussard is to remain in as much control as possible. I have dealt with billionaire's before. While they are mostly well meaning, the old adage that power corrupts is all too true. The best thing that Doc could do from my point of view is duplicate the WB-6 results again. If the results meet peer review, I don't see why the NAVY would not want a fusion fleet. In this country, for better or worse, the military always plays with stuff for 20 years before we let it loose on the public. Then someone is going to have to put it on an aerospace plane. The CIA and USAF come to mind there. NASA should have a plan to mate this fusion power plant with something like the X-33. Does anyone know who is in charge of advanced projects at Lockheed now?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 06:59 PM
Quote
Tony Rusi - 10/5/2007  2:48 PM

 I don't see why the NAVY would not want a fusion fleet.

Tony, that is 100% rational and logical, BUT...Considering who is running the foreign policy apparatus in the US right now, the military is being used as more than a saber rattler towards oil rich nations. If one takes oil out of the equation....and inserts IEC fusion.... you just removed one reason for a large Navy. There is a minority in the world who currently think the planet is approaching a period of resource wars.

+++++++++++++++
I organized my first political fund raising Dinner for a Congressional candidate, last year. Doesn't make me an expert by any means.

Fundraising breaks down to 2 angles these days"
1) small donations, from lots of people.
2) huge donations, a lot fewer people.

For various reasons, which I wont get into here, most people are not going donate money, or buy a tee shirt/bumper sticker. AS a business model this is not grassroots politics (something I have some knowledge of). The odds are much better that I can get 20,000 people to donate $50 to my friend's congressional campaign, than to get 20,000 people to donate $50 to Dr Bussard. That not to say that tee shirts, (I prefer the Izod type) and bumper stickers don't have their place, they do.

I have had some thoughts:

Network

-My Dad teaches @ SUNY Long Island, knows folks in the Physics dept.
-I know folks who know Rush Holt (NJ12) and folks @ Princeton University.
-Bruce Springsteen lives in NJ, he knows Sting & Bono.
-I know the folks from Climatecrisis.org

Which leads to the question of what mechanisms can be used to bring this larger group of people on board.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 07:03 PM
Tony,

Yeah. Power corrupts.

The important thing is to work with people who want to make money on a new technology.

As long as it doesn't get shelved I don't care who profits or by how much. As long as there is coal left the profits will be limited to market forces.

Think of the atom bomb. Even hidden, the technology has proliferated. Why? It was demonstrated to work.

==

No man can remain in control. Death severely limits that option.

Having to go to others for money is another severe crimp.

==

The other option is Government finance.

So far no one has any faith in that. Rightly so. It is governed by political whims.

The way to beat that is to build a political movement.

So far the google video has had 100,000 views. We need to get that up to 1,000,000 or better yet 10,000,000.

==

What I found really interesting is that the Space Show said it was just about their most popular topic.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 07:12 PM
Fox,

Why not turn this into a political campaign? Which is sort of what I suggested above. It was also part of my e-mail I sent to the Space Show.

Tom - you are going to speak to a bunch of people. Make sure they contact their Congress critters.

The only way to make this semi-public domain is for government to finance it.

I'm not big on goverrnment, but government funding of research would be good from a number of points of view. You get companies licensing the technology instead of owning it. The data is in the public domain.  Other governments might go into competition.

Cold Fusion is worth a couple of mil a year. IEC fusion ought to be worth as much.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 07:20 PM
Quote
M Simon - 10/5/2007  3:03 PM

The important thing is to work with people who want to make money on a new technology......
The way to beat that is to build a political movement.

Yes, & yes.

IMHO the only folks who are going to make this work, have money and want more.  The one person who sees the 100 year+ upside is the one I want to see move forward on this. Corporations will go to the moon, asteroids, mine them and make a friggin ton of money. IEC looks to be the key to unlock the Solar System.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 07:43 PM
Toni,

Heh, heh, heh (Tom polishes his skunk pin).

I'd tell you, but then I'd have to kill you.

No budget for fusion at Lockheed Martin at present, I think.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 07:57 PM
On the Space Show Dr. Bussard said that any country with a machine shop should be able to build his reactor.  So what costs money?  Just man-hours?  Just raw materials?  If he could find a machine shop that would rent him the equipment, then could he reduce the costs that way?  Kindof a do-it-yourself thing.  Is there anything that would be truely expensive, requiring some ultra-high tech or ultra-high precision fabrication process?

Here's an idea:

He could sell kits to amateurs wanting to build fusors.  Hobbiests love that kind of stuff.  Do it so the amateur has a choice of what size to build.  Scalability.

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 08:00 PM
Quote
M Simon - 10/5/2007  3:12 PM

Fox,

Why not turn this into a political campaign?

Please re read. You are way off target.

The issue I raised was the type of campaign. Not: should there be a campaign?
Title: Re: Fusion with space related aspects thread
Post by: Lee Jay on 05/10/2007 08:01 PM
Quote
Is there anything that would be truely expensive, ...

Engineering, and for the test objects, instrumentation and labor.

That's my guess, anyways.

Lee Jay
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 08:15 PM
A while back I discovered there are companies that sell miniature CNC machining tools for hobbiests.  One example:

http://www.sherline.com/

These machines are pretty cheap, maybe $1000.  If you add CNC capability maybe $3000.  If you want to machine steel you need a more powerful motor, but some of these home machines can accommodate.  As shown they even have fixtures for stereo microscopes.  Hobbiests do some seriously sophisticated things these days.  And engineering is really all in the software anyway.  If you can do it yourself, you don't have to pay someone else to do it.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 08:21 PM
Up dated links for my videos

IEC Fusion for Dummies

http://www.youtube.com/watch?v=XiHsSAS_SQw

Alternate source for for IEC Fusion for Dummies, downloadable in wmv format too:

http://fogerrox.blip.tv/file/223363/

IEC Fusion vs Tokamak Fusion

http://www.youtube.com/watch?v=rBfsq80EgOs
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 08:57 PM
Semper,

You should see some of the gorgeous things being machined by the amateur fusion bunch over at fusor.net.  Some of them have made their own spherical vacuum chambers.  I know one who makes superconductors.   I have no doubt there are people over there more than capable of making small machines of the WB-6 form factor.  They typically already have deuterium and neutron counters.  To switch to this type of machine, they need higher-current power supplies of positive output rather than negative, some way to supply floating high current to the magnets (typically RV batteries), larger vacuum chambers than fusors typically use, and better vacuum (although a few of them already have turbopumps).

A few of them are thinking hard about trying it.  Some of them are probably also capable of doing some decent modeling of the physics.  They may be amateurs, but that doesn't mean some of them are not VERY knowledgable about IEC fusion physics.

One source of relatively inexpensive NC equipment is Grizzly.  It is not top-notch stuff, but cheap and the right size and power type for home shops.  Mills can go as low as $500, NC adds a few thousand typically, so your estimate is pretty good.

http://www.grizzly.com/

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 09:07 PM
I guess my question is:

If even a very expensive CNC machine costs $40,000 and you could make anything with it, then why would the research for WB7 and WB8 cost $3 million - $5 million ?

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 09:34 PM
Overhead?

I think the question comes down to how many people of what pay grades it will take to do this, and how much outside contracting it will take.

Let's guess it will take a good mechanical engineer, a good electrical engineer with a gaseous electronics background,  a top experimental physicist (Bussard or equivalent), a top theoretical physicist (Krall or equivalent), two supporting physicists, a computer programmer, office manager, receptionist.  Nine people.   Nine people is 18720 person-hours/year.  I don't know what a good estimate for a burdened labor rate is these days ... let's use $100 for the sake of argument.  That's $1.87M in a single year!  In house, labor is less by maybe a margin of 3, so maybe 2 million will provide about 3 years labor? But you must include rent, insurance, benefits, utilities.  Really fuzzy average numbers.  

Durn, I left out the whopping salary for a publicity consultant/SF writer!  But we know he'll work for free.

The machining for WB7/8 would probably be done under contract, but it wouldn't cost much.  EMC2 had a drill press ... I'd opt for a small mill to do quick modifications and little jobs, but I'd let the pros build the magnet cases.

I designed the vacuum chamber, and still have the drawings.  But it was built by a shop that specializes in vacuum chambers.  It cost somewhere in the $200k range, and it had something like another $150 k of turbopumps, roots blowers, forepumps, and traps on it.  All that is stored at SpaceDev, and could be put back in service if a government contract were evoked.

When I started for EMC2, we had a grant of $60k on which to operate for 6 months.  I did the math.  It paid me, the office manager, the rent, and the utilities, and bought some equipment.  Dr. Bussard worked for free.

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 09:38 PM
Quote
SemperUbiSububi - 10/5/2007  5:07 PM

I guess my question is:

If even a very expensive CNC machine costs $40,000 and you could make anything with it, then why would the research for WB7 and WB8 cost $3 million - $5 million ?


Just off the top of my head....

Rent for lab.
Do you want a proper power source, or use capacitor banks?
Salaries, 15 @ 50k to 100k/annum
Machine shop or outsource fabrication?
Vacum chamber

EDIT: Oh I see Tom covered it much better.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/10/2007 11:13 PM
If you have an office manager, you don't need a receptionist.  Eight people.

If you have an electrical engineer, you don't need a computer programmer.  Seven people.

No reason given for two supporting physicists.  Five people.

You've done the design for the vacuum chamber.  So no need for an additional mechanical engineer.  Your down to four people.

Four people:
Dr. Bussard = programming, number crunching, writes technical papers
Tom Ligon = engineering designs, assembly, vacuum chamber, publicity
Electrical engineer = electrical interfaces, magnets, power supply
Office Manager = answers phones, bookkeeping, sources suppliers


Home business.  No overhead.  My former employer started his blown film plastic extrusion business with a small machine in his basement.  The top nip rollers were in the attic.  Must have done a serious job on the architecture, but he paid rent to nobody.

Four people instead of nine would reduce the labor cost to around $800,000 per year.  Hardware/utilities/insurance/etc. might cost another $200,000.  So that's a $1 million bucks per year.

Ok.  I think I see where Dr. Bussard got his lower estimate.  Maybe he planned on 5 people.  His wife maybe?

I don't know how I can contribute to this process with the concerns I pointed out earlier.  Maybe I'll just wait and see what happens in the future.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/10/2007 11:37 PM
Not even 3 or 4 able bodies.... I dunno...
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 11:37 PM
BarryKirk,

Sorry, you kind of slipped thru the cracks with all the posts!

Regarding suspending magrid components on cables, two problems.

1) The support system must be an excellent electrical insulator.  At least one of the insulators will carry a high voltage conductor for the magrid surface inside, which might also be a deuterium feed line, but you don't want a non-magnetically insulated conductor exposed.  A pair of high current conductors for the magnets will go thru at least a second pair of insulators.  These also need to be floating at high voltage or they will arc to the magrid case (that's what killed WB6, in fact).

2) The magnets are under fairly strong mutual repulsion, and may also be affected by magnetic influences outside the vacuum chamber.  My idea of having independent magnets, without the interconnect, supported by many insulators, was intended to handle that repulsion.  

You could suspend the magrid, assembled with interconnects, on some form of tension elements, rather than supporting from the bottom, and they would be thinner.  They would have to be insulated.

I believe they may have used the four fat supports, located where they did, because the main exterior recirculation of electrons is from corner cusp to face cusp, a distinct loop.  Putting the supports between these loops puts them in a region of very low electron density, and also at the point at which the magrid struture is most rigid.  The very low density makes the size of the supports less important.

If those interconnects between the magnets are, in fact, one of the larger remaining losses, supporting the magnets individually by the big insulators, again behind and outside the points where the magnets are almost touching, should give strength at the point of highest repulsive force and also where the electron current is lowest.

On reason WB6 specifically was supported from the bottom was convenience.  The vacuum chamber has railroad tracks in the bottom.  They had a little cart to roll it into position.  That was vital with WB4, which was built like a tank and weighed a substantial-enough fraction of a ton that they probably could not have manhandled it into position.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/10/2007 11:48 PM
Semper,

If you split Electrical Engineering between myself and Dr. Bussard, and allow a little consulting on occasion with Dr. Krall and Physicist/programmer Lorin Jameson, you just described the Manassas Park lab.

Dr. Bussard had a small machine shop in his basement.

The lab space was rented.  It was actually low-rent office space, the last place you'd expect to find a fusion lab.  The rent was very reasonable, but the most power we could draw was from a kitchen range jack (208V 50A single phase).  The other tenants probably wondered why their computers occasionally behaved so strangely.

What he needs is a place way out in the desert, with tons of power.  But not so far out nobody will want to work there.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/10/2007 11:58 PM
Here is my list:

1. Plasma physicist
2. Machinist - Mechanical Engineer
3. Heat transfer and fluid flow  expert
4. Electrical Engineer - quasi programmer
5. Mathematician/Programmer
6. Purchasing Agent/Book keeper/Office Manager
7/8. Two technicians - electrical/electronic - mechanical
9. Publicity guy - customer relations

The organization will need to be changed and enlarged to do the 1 to 100MW job.

I still think that to get to 100 MW you will need to get there in stages. To go from 100 mw or less with copper coils to 100 MW with cryogenics in 1 jump is not reasonable from an engineering stand point. Not even the fission guys were that ambitious. They built numerous test reactors from 100 w to 100 Kw before making the jump to 30 MWth.

Sure you can eliminate bodies but then you run the risk of unforced error due to lack of expertise.

Just ask Tom about what choosing the wrong insulation for some magnet wire cost him. Short answer - significant operational time.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 12:08 AM
Now you might ask why do you need all these people.

You probably could cut some. The heat transfer guy probably is not essential at first.

However you gain time when you want to scale up to higher power. You have the core team for your next steps.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 12:13 AM
"An online critic of Scientology was confronted at a routine hearing Tuesday with surprise arrest warrants and thrown into jail. Six years as a fugitive ended in February. (After picketing a Scientology complex in 2000 over the unexplained death of a woman there, he'd been arrested for 'threatening a religion' over a Usenet joke about 'Tom Cruise Missiles.') But 64-year-old Keith Henson had been out on bail, and was even scheduled to address the European Space Agency conference on Space Elevators. He's a co-founder of the Space Colony movement, and one of the original researchers at Texas Instruments. In this interview he discusses both space-based solar energy and his war with the Scientologists — just a few days before he was arrested."


http://yro.slashdot.org/yro/07/05/10/1349237.shtml

Interview here;

http://www.rusiriusradio.com/2007/05/01/show-104-keith-hensons-space-elevator/
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 12:15 AM
MSimon,

The fission reactor guys sneaked up on it.  The fission bomb guys were purely brazen.  The Hiroshima bomb, the U235 gun design, was never even tested, unless you count Hiroshima as the test.  The were so sure it would work they just loaded it on the plane and dropped it.

They were less sure about the spherical plutonium design, in part because the high explosive had been problematic.  As a result, they underestimated the yield quite a bit.  And that was not the last time they underestimated yield.

I would feel more comfortable sneaking up on net power in a few stages.  The investors are very likely to feel the same way.  But I do believe that going straight to net-power size is very likely to make a reactor that does produce net power.  It very likely would not do so for very long.  An elegant, durable machine with useful electrical power output would probably need some intermediate stages.

I still like the rocket fuel idea ... study heat loading at mid scales using rocket fuel to simulate the power load of a net-power-size machine.


Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 12:52 AM
I was looking through the referers log at my blog and came across this Slashdot article about funding for Bussards work (the earlier  erronius report)

http://hardware.slashdot.org/article.pl?sid=07/04/22/2115249

They reference my blog on the news - I have updated that page with a link to Tom's  explanation (contract extension - no money).

In fact a significant amount of my recent traffic is about fusion something like 20% to 30%. This is a significant change from a month or two ago.

The above page has 419 comments as of this post. Wow.

There is an on line petition to get funding:

http://www.petitionspot.com/petitions/fundiecf

another funding article from about 18 April.

http://advancednano.blogspot.com/2007/04/bussard-fusion-navy-contract-renewed.html




Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 01:27 AM
Quote
M Simon - 10/5/2007  8:08 PM

 You have the core team for your next steps.

This is an extremely important comment. Thank you M Simon. Tom correct me if I am wrong. In a nutshell, there will be probably 2 WB6 sized devices, a truncated cube, a truncated dodecahedron. Then from there, upscaling is possible, wether the program goes full size or takes an intermediate step, we are talking about a minimum of 3 devices, probably more, possibly 6+ devices.

Taking the bean counter approach is flat out stupid, M Simons comment reminded me of that very important fact.

What will be far more vital is forming a team, a team that has to build 3 to 6 devices. The end result will be net power, the best way to get there is to build a team. You don't build a team with  a bean counter mentality. I've got 20+ yrs as a personal manager, & I needed M Simon to remind me, thank you my friend.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 01:33 AM
The reason the bomb guys were so sure is that they had fewer variables to deal with.

All they needed was the capture cross section for unmoderated neutrons and a few other things to be sure it would go off. Capture cross sections for  between 1 to 5 Mev for the neutrons  is pretty constant.

The thermal guys had a lot more to worry about. Like cooling. Thermal neutron cross sections.  Resonance absorbtion. The cross sections in operation of a lot of different materials.

As to one short run at 100 MW - bad publicity.

Do your required experiments at low power so if things go wrong the numbers aren't so big.

Think of it: 100,000,000 watt reactor explodes. 100 watt reactor explodes.

Or try 100,000 kilowatt reactor explodes.  1 kilowatt reactor explodes.  At 1 kilowatt it is almost a familiar number. Electric heaters. Not too scary. 100 watts is just a lightbulb.

There is way more to this than just the technology.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 01:40 AM
FogerRox,

As an engineer I was often on the wrong side of that equation.

When it really, really, hurts you personally  it improves the memory. LOL

Simon

Another point I left out is cross training. You can cover for sickness. Family stuff. Better offers. etc.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 01:57 AM
Quote
M Simon - 10/5/2007  9:40 PM

  it improves the memory.

Touche~
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/11/2007 02:12 AM
Would it save time and money to build a big vacuum chamber now, big enough to test any size reactor all the way up to the Demo reactor?

Is that a good idea, or a waste?
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/11/2007 02:37 AM
I believe that there are options out there to get this project funded if one looks hard.
The Citicorp and Bank of America are with respectively 50 and 20 billion are just examples. JP Morgan has a similar program however they did not announce the budget. Those monies maybe hard to get since they are big corporations and which in a way work similar to the way government does. The decision makers have no idea what the science is about.
Regardless of all of that there are private individuals that could and probably would be interested in funding if we found a way to get to them.
On Feb 10th Richard Branson offered $25 million prize who can remove 1 billion tons of CO2 from atmosphere.
http://curtrosengren.typepad.com/alternative_energy/2007/02/richard_branson.html
„The first $5 million would be paid up front; the remainder would be paid only after the program had worked successfully for 10 years”
Well, Dr Bussard knows Jim Benson who knows Burt Rutan, who knows Richard Branson...
Maybe that is the way to go.
There are a some  out there who have the money and would like to leave their name in history books.  Paul Allen mentioned once that he and Bill Gates were discussing a possibility of sponsoring fusion research, but decided against it due to the political/scientific climate at that time.
Here is a list of the 50 most generous philantropists
http://www.businessweek.com/pdfs/2005/0548_philsco.pdf

Gordon and Betty Moore that are at the top gave $7 billion for science and environment based projects between 2001 and 2005
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 02:49 AM
And Bussard knows Gary Hudson who knows Burt Rutan ...

But I guess Branson has done his good deed.  I wonder who else thinks it is time to become a philanthropist?  

Dr. Bussard once told me "You don't find angels, angels find you."  They get approached all the time, and know how to say "no".  But when they seek you out, it is to say "yes."  That happened to Dr. Bussard a couple of decades ago when Bob Guccione funded about $17M of work on "the Riggatron."

Which has probably come back to haunt the good doctor now, as they were unable to raise the capital to build it (similar amount to a DD Polywell) and now a lot of people think it was a failure.   The present project was, in fact, born from the Riggatron's ashes.  But do you get a second chance with another angel?  No point hiding the past ... they have financial advisors.

A few decades ago, Dr. Bussard was pretty well-connected politically, working closely with Jack Kemp.  He also participated in some nuclear disarmament talks.   He has met a lot of folks over the years.  Hopefully one of those connections will pay off.

I can't get down to ISDC on the 24th ... I wish I could.  There is a Space Venture Finance Symposium on that date, and NSS Director George Whitesides sent me a free invitation to attend (most folks have to pay).  But that means people with that sort of business leanings will be at the conference, and I'll be free to meet them all weekend.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/11/2007 03:13 AM
Hi Tom,

It looks then that the only thing we can do is to get the word out to as many people as we can.
Keep up the good work.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 03:18 AM
Quote
SemperUbiSububi - 10/5/2007  10:12 PM
 build a big vacuum chamber now,

Is the old 6 ft chamber in storage? If so, then of course no.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 03:35 AM
MSimon,

The one thing I'm sure of is that a Polywell won't explode. The relatively small density envelope in which net power is possible means too much fuel just chokes them off.  That's why WB6 ran for such a short time.

I am really glad, though, the Dr. Bussard did not hit a moderately higher rate of neutron production for half a minute in the little light industrial park in San Diego where WB6 ran.   And hitting DD breakeven at a 100 MW, or even kW level, in the wrong location, unshielded, would be bad publicity, too.

There is a safe intermediate strategy, one that gets around the problem of deadly neutron baths and huge heat loads of fusion products on the magrid, but it lacks drama and tends to sound wishy-washy.  It is called "demonstrated breakeven."  You dilute fusion fuel.  For DD, if you mix one part D with 100 parts H, the resulting reaction rate will be down 10,000 from what you would get with pure DD.  So you get your neutron count, calculate the power, multipy by 10,000, declare victory, and break out the bubbly.

And everybody says, waitaminnit!

That probably will be an intermediate step, but nothing says fusion like real net power.  When you hit demonstrated breakeven, you start bringing in the freight cars of boron-doped polyethylene bricks, or whatever other neutron shield you decide is effective, and start runs at higher D concentrations.  It does also give a way to sneak up on the cooling problem.  A similar strategy should work for p-B11, where the heat load is the larger problem but there is also a non-trival bremsstrahlung radiation problem.

Semper,  the big vacuum chamber is a really huge capital expense.  I would expect a year or two leadtime to build it, and it would be a budget buster at the WB7/8 level.  It might come into play if intermediate sizes capable of, say 1MW and 10 MW operation (below net power but with high fusion rates) were decided on as risk mitigation steps.  Those would not be greatly smaller than the full size 100MW unit, and might be close enough to the final size to justify the big chamber.  Cost might be controlled by not installing the full pumping capacity.  The chamber probably costs more than any magrid, so using a chamber to test more than one size may make sense.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/11/2007 08:19 AM
Tom,

Everyone keeps calling Bussard's device electrostatic. Isn't that wrong? I thought it was fundamentally different. I thought it was electrodynamic. Even the Bussard wiki is still wrong. Could you please explain this?? Most physicists still lump them together.

I really wish that there was a high school kid table top fusion competition to push this technology along.

Doc keeps on saying that the devil is in the details. Virtual grids are fundamentally new technology. He keeps saying that high current and high tesla superconducting magnets don't exist. You say that superconducting magnets could reduce the size of the device. Some days Bussard agrees.

I think that is a huge key point! What the world needs is something the size of a light bulb that can power their house for a year and then can be thrown away. You could probably get around 2 or 3 thousand bucks each for them. Every year! You could be the next Bill Gates! I think the key to the light bulb size unit has to be superconducting magnets of some kind, and in pulsed operation.

You keep on saying lets do this in the desert somewhere. I hate the desert! Google is going to the Dalles Oregon because that's where the cheap power is for their server farm! Hanford is not too far from there and it is a desert and there are a few nuclear engineers out there already. (Yuck!)

Nathan Myhrvold has funded some fusion work before. He was the CTO at microsoft for a long time. I think someone should ring his doorbell with the WB-6 in tow. I think it is a crime that there is a $200k vacuum system gathering dust in San Diego!

http://en.wikipedia.org/wiki/Nathan_Myhrvold

I have always been told that the definintion of a great engineer, is doing for one dollar what any schmoe can do for ten.  In WWII the nazi's thought they needed heavy water for nukes when the americans discovered that parafin worked just as well. So what are the expensive poles in the Bussard Tent? A good vacuum system? A smaller overall size? Are superconducting magnets expensive? So would cheap high beta high amp magnets be the big breakthrough? There is a guy in Vegas that built an arc plasma testing device for NASA in Ohio. Each copper coil had about ten garden hoses hooked to it.

NASA dept. admin. Doug Cooke is supposed to be studying the best way to get to Mars with a report due in August. I think it is nuts to go to mars with a manned craft that takes more than a month, just from a cost point of view. It seems like Fusion has been abondoned by the right and the left for different reasons. There really should be a fusion prize. And there are alot of rich people in this country that could fund this. George Lucas used a fusion reactor the size of a small coffee can in Star Wars. Steven Speilberg had a popcorn popper called mr. Fusion on the back of the time machine. Small is better.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 11:09 AM
A big chamber requires big pumps.

Actually we will probably need multiple chambers.

If something unexpected comes up in one of the larger sizes it may be useful to work at a smaller scale to fix the problem.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 11:33 AM
Tom,

You will notice all the bad publicity  just from the magnets burning up in the Drs. last experiment. A plasma physicist contacted me about it and he thought the work was amateurish just because of that. I wasn't thinking strictly of nuclear explosions.

My favorite for neutron shielding is a water tank about a foot thick filled with borated water. Followed by either a thick wall of steel or lead bricks or even lots of concrete to stop the gammas. If you are out in the desert the shield wall need only cover one side of the reactor.

==

A good read on bad publicity killing a good idea - read about the car accident that killed Bucky Fuller's Dymaxion car. The accident had nothing to do with the viability of the project. Yet the bad publicity killed the idea.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 11:42 AM
Tony,

If you are going to make a power reactor using natural uranium, heavy water is a requirement. In fact the US built a number of carbon moderated and also heavy water moderated natural uranium reactors during WW2. Once they had a supply of enriched uranium they switched to water moderated reactors.

I have a book published in 1953 on reactor design that goes deep into all those questions. I read it every night.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 12:04 PM
Tony,

Because of the physics there is a minimum size. You have the same problem with nuclear fission reactors. Critical mass.

I'm sure once we start building these things en-mass some one will come up with better ideas.

The first natural uranium piles were quite large because of the small amount of U235 in natural uranium. Once they got quantities of the enriched stuff the minimum reactor size got small. One foot across was estimated to be the minimum size. Three feet across was considered better because of the problem of energy density. We will have similar energy density (cooling) problems in a 100 MW fusion job. The first submarine prototype reactor was 60 MWth.

From an engineering stand point I think a series of reactors each 2X the previous size is the way to go, increasing the power by a factor of about 100 at each step. The mass of eqpt needed will go up by a factor of about 10X at each step (r^3).

===

Tom,

The energy stored in the magnets will be quite explosive if released in a short time. You don't need a nuclear explosion. Because of the "nuclear" designation, the general public will think nuclear explosion even if it is only the magnets going up in smoke.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 12:34 PM
I have always been told that the definintion of a great engineer, is doing for one dollar what any schmoe can do for ten.

Yep.  Except sometimes you need to spend millions to get that 10:1 reduction.

I was working in aerospace where we needed a million and a half $ tests set that took a year + to build. The design of that set was done. Except we didn't have the $1.5 mil. and especially we didn't have a year and a half. I figured out how to cut the time to under 3 months (actually had a unit that was half built but could be used for testing in 6 weeks). The first one cost $.5 mil in materials and engineering. After that copies were rolled out in about 4 weeks at a cost of $100K ea.  So yeah. It is possible to short cut. However, my test set was the absolute minimum required at the stage of testing it was used for. (The $1.5 mil jobs were production testers that measured every thing - I only wanted to know on or off, contact resistance was of no interest at the stage of testing I was doing).

This project with so many unknowns is probably going to cost a lot more than the initial estimates.

The total will most likely be $1 bn once you design build and test an actual power producer that connects to the grid.

After the first unit has been tested for 6 months of grid load you can go into series production and you could probably turn out copies for $100 mil or less.

I don't see these as basement generators. Neighborhood generators is a definite possibility. Locate them in switch yards. The building would be about the size of a telco central office.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 01:49 PM
MSimon,

When I came on board, Dr. Bussard still used the term "electrostatic", or at least classified Polywell devices in the IEC category.  

As time progressed, he started using "electrodynamic".  This was probably because so many people seemed to have the notion that the electrons were injected and became stuck in the magnetic field like raisins in oatmeal.  After repeatedly correcting this misunderstanding, and explaining that the electron potential well exists and is maintained only because the electrons are in constant high-energy motion, he must have decided to emphasize the motion by changing the name.

As far as the ions are concerned, the forces are close to the same as the electrostatic forces in a Hirsch-Farnsworth fusor, just without the grids.

We looked into a WB6-sized device using liquid helium superconductors, consulting with probably the best builder in the world.  He considered the structure needed ... LN2 and liquid helium jackets separated by vacuum jackets, which need to withstand the repuslion forces.  That means the various jackets need mechanical elements crossing them that shunt (leak) heat.  He concluded superconductors are impractical until a substantially larger size.

You certainly understand all the heat load problems better than most.

Since then, high-temperature superconductor fabrication has matured.  We obtained some samples of an LN2 superconducting ribbon around 2000, but it looked too delicate to make the magnets we needed.  Now, it may be a workable option, and I have a friend who thinks he could build them for price that would not break the bank.  He also thinks he can push copper magnets ten times as hard as we were, by using an advanced construction technique.  He holds a world's record for copper magnet field strength.

Tony Rusi found something intermediate, an aluminum coil magnet that is cyro-cooled and achieves ultra-low resistance, short of superconductivity.  Even copper, at LN2 tempertatures, might be an option.

The magnet problem at WB-6 scales can be beat ... just bring the right person on board.

Eight high schoolers have achieved fusion so far, two more are close, and they keep showing up at the fusor.net website.  Occasionally one makes the national news (Thiago Olsen was the one last fall).  I want to see one try electrodynamic fusion next, or at least a small-scale electron trap.

I'm from Virginia.  Desert has no charm for me, either.  Dr. Bussard was born in that there briar patch, and loves it.  If we go for p-B11, we can build anywhere with modest space available.  If we go for DD, China Lake has been mentioned.  The soil is loaded with boron, and I'm told there is a geothermal power plant there and power is abundant.  Alas, you have to pay the workers more because the place lives up to its name ... baked white featureless desert.  At least China Lake tends not to be overrun with NIMBYs.

It apparently never went very far (no reference to it on NASA's internet sites) but there was a scheme called "Strategy F" making the rounds, at least at Marshall, in the mid-late 90's.  F stood for fission or fusion, as the power source to propel human spaceflight for Mars.  Two of the three options were Dr. Bussard's babies, either Rover/NERVA fission propulsion, or his QED/CSR or ARC proposals.  The third was tokamak power ... stick ITER on the back of a rocket (snicker).  They know they want it.  They just don't have a budget set aside for it.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 02:03 PM
MSimon,

Energy stored in big magnets is often overlooked.  I've been told the ITER magnets will store about a kiloton in total.  Let one of them warm up to critical temperature, it will go resistive, heat further, and dump that energy almost instantly, exploding, taking out the rest.  Radioactive reactor guts and molten lithium all over the place.  Not pretty.  They claim to have ways to dissipate the energy quickly if a coolant failure occurs.

The net power Polywell will be much smaller, but no doubt a blown magnet would still be dangerous.  One of the charms of p-B11 would be that any accident with the magnets would not involve release of radioactive materials.  Dissipation of the energy in case of a leak would be easier than for ITER by a large factor, though it will certainly be a non-trivial amount of energy.

Steam explosions are unpleasant, too.  Also rare.  I expect safety will be at least as high a priority with Polywell reactors as it is at other modern power plants.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/11/2007 02:16 PM
Yes, I agree that the mechanical supports should be located in a section where the density of recirculating electrons is very low.

But I think I missed a point.

I kept reading that non magnetically shielded conductors in the path of the electron flow is very bad because they absorb the energy of the electrons.

Are insulators not as much of a problem?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 02:36 PM
BarryKirk,

Insulators are not a problem if electron density is modest and ions are not confined in the vicinity.  Outside the magrid, ions go straight to the walls.  A few electrons may stick to the insulator surface, charge it up, and cause it to repel any other electrons.

Where both species are present, electrons charge up the insulator and attract ions to it.  If you try to use insulators inside the magrid, all sorts of fireworks may ensue.  We tried that on a couple of occaions in a vain attempt to shield electron loss paths.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/11/2007 04:49 PM
So, would a conductor with a slight negative charge keep the electrons away?

The thing that brings me back to conductors is that they have several advantages over insulators.

1) They are usually metals and therefore mallable, Easier to shape.  Metals are just easier to work with than
ceramics.
2) You need to run conductors to the MaGrid anyway to provide it with power.  Unless you are thinking of inducing an electric current in the MaGrid like an induction AC motor.


Second topic,

The talk of vacuum chamber size and pump sizing.

Something which I understand in principle, but have no working experience with.

Is the major cost of a vacuum chamber the pumps?

Most especially the pumps to generate a really hard vacuum?

What about building the largest chamber you could possibly need and then only pumping it down to a moderate vacuum.  Say 0.1 torr

Inside of that, put the actuall smaller vacuum chamber that gets pumped down to a really hard vacuum.

Their are several advantages.

1) The inside vacuum doesn't need any real structural strength.  The outside pressure is insignificant.
2) The leakage rate of air entering the inner chamber is very low.  The pressure difference across the inner
chamber is almost zero.

Just a thought.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/11/2007 05:00 PM
How does this compare to Focus Fusion

http://focusfusion.org/log/index.php

and Colliding Plasma Toroid Fusion

http://www.electronpowersystems.com/index.html

Who have plans for fusion cars and individual home fusion units for back up power.

http://www.electronpowersystems.com/Applications.htm

http://www.electronpowersystems.com/Images/6kw%20wp%20non%20prop.doe.pdf


http://peswiki.com/index.php/Directory:Fusion
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 06:20 PM
The target inside pressure on the tank was <1e-8 torr at rest, with no fusion activity.  

As far as the structural strength of the chamber goes, the difference between inside and outside pressure of the large chamber is essentially the same regardless of whether the inside pressure is 0.1 torr or 1e-12 torr.  One atmosphere.   So you would not save anything with two nested chambers.  The huge outer chamber costs all the money.

But something like that was a feature on the door.  The door featured double concentric o-rings, with a channel in between.  If the inner o-ring were found to leak, we had the option of pulling a modest vacuum on the channel.  1e-2 torr on the channel would tend to drop the leak rate by a factor of as much as 10,000.

An inner shell might have another use though.  When it first arrived, that big San Diego chamber had a gorgeous electropolished mirror finish (dramatically reduces outgassing).  By the time of the pictures, it had a purple hue.  A disposable shield in the chamber might be useful if the fusion products and other high-energy mayhem were found to degrade the chamber walls.  We might well have MSimon design that inner shell with lots and lots of cooling.  It could be optimized for heat load rather than strength.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 06:26 PM
From what I've seen of Focus Fusion, it is still a Maxwellianized thermal technique.  They have good taste in fusion fuels ... they like p-B11, too.  I see some similarity between their approach and Paul Kolok's spheromak ball lightning model, which I know has some prospect to do at least some DT fusion.

If they can get it to work and put it in a car, a Polywell probably can never be made that small.

When I first found their website, it was because they had a news article posted about Dr. Bussard's project.  They had nice things to say ... said Dr. Bussard was apparently at about the same stage they were.  Consequently, I have nothing bad to say about them.  :)

There's certainly room enough in this world for more than one effort ... we're in the mess we are now because we focussed on lasers and tokamaks to the exclusion of all else.  I wish 'em well.  But I understand Dr. Bussard's approach and think it is the right way.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/11/2007 06:46 PM
Quote
Tom Ligon - 11/5/2007  1:26 PM


If they can get it to work and put it in a car, a Polywell probably can never be made that small.


Love to see the faces of those from the Middle East should they do so.... :)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 07:15 PM
The problem with insulators in a long term operation is the sputtering of conductive material from the grid, the collector grid and the walls, getting redeposited on the insulators.

As to getting a lot of current through copper - if you could settle for 2X less than maximum performance I could probably do the design. Isolating the pumping stuff from the grid voltage ought to be fun. Keeping the water de-ionized should be interesting. Fortunately the nuke guys have solved a lot of these problems for stainless steel.

I still don't  see why permanent magnets wouldn't work - at least for testing p-B11. The neutron flux should be low. Depleted (of D and T) Hydrogen  should be available - you buy it from the guys that sell D.

I believe the current maximum for permanent magnets commercially available is 1.2 T - the reactor justs gets a bit bigger than with a 1.5 T magnet. Worth it if you can eliminate the need for superconductors. Put them inside of a copper tube and pump a lot of fluids to keep them cool. Below 80 C I think.

High temp superconductors get wrapped in a silver case I believe.  You can't bend them like copper wire, but they are bendable. Even with the high temp stuff your gain is limited - depending on the cooling losses at 70 deg. K. A lot better than 4 deg K for sure. The question is could you do better with copper tube despite higher losses? It is an engineering question. I can take kilowatts out of copper easier than I can take watts out of 77 deg K. For one thing - I don't need a refrigerator. I can run it at  150 - 250 deg C and use a fairly small air cooler. Which might be a bias for working some place where water is plentiful - you just do a total loss system. If net performance is not an object and you don't have to run continuously buy a truck of LN2 when you want to do something interesting. That should reduce losses in the copper and thus allow higher currents. Heck, keep a tank of it on site.

BTW the pumping losses in a nuke plant are huge. Something like 10% of the electrical power output goes to running the cooling pumps at full power. If you run at less than full power the losses decline relative to net output until you get to a minimum (due to elecrtrical losses in the wiring, pump friction, etc.)

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 07:33 PM
The company focus fusion is centered on:

http://lawrencevilleplasmaphysics.com/

says on their website that they have signed a $10m Licensing Agreement with  CMEF of Sweden:

http://www.cmef.eu/main.asp?show=menu1_2

 a google news archive search (for CMEF Sweden AB) finds nothing but 50 to 120 yr old hits:

http://news.google.com/archivesearch?q=CMEF+Sweden+AB&btnG=Search+Archives&ie=UTF-8&oe=UTF-8

A regular google news search comes up completely blank:

http://news.google.com/news?ie=UTF-8&oe=UTF-8&q=CMEF%20Sweden%20AB&um=1&sa=N&tab=wn

Apparently Lawrenceville Plasma Physics, Inc. will receive an initial payment of $600,000 untill proof of concept.

Quote
“This license will provide LPP with the immediate funds it needs over the next year to finance data analysis and simulations for our on-going experiment in collaboration with the Chilean Nuclear Energy Commission,” says LPP President Eric J. Lerner.

Eric J. Lerner seems interesting:

http://news.google.com/archivesearch?q=Eric+J.+Lerner&btnG=Search+Archives&ie=UTF-8&oe=UTF-8

http://www.tipmagazine.com/news.html

http://www.columbia.edu/cu/21stC/issue-4.2/lerner.html
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 07:40 PM
A failure analysis engineer is going to be required to design the safety systems once you get above around 1 KW.

Some one with aircraft or nuclear power experience should do.

Did I mention I have both? Heh.

I really, really, want to work on this in some capacity. I'm retired and will work for technician's wages.

A pipe dream probably.

In any case I can broaden my understanding and get the publicity out.

Googled - Bussard Fusion - 92,000 hits.

Two of my pages come up at #5 and #6 - wow. I guess that makes me the expert. Ha. I rely on Tom for my backup.

BTW Tom, when your talk is done are you going to put up your slides etc.?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 07:58 PM
MSimon,

I think ISDC may post my slides.  If I submit them ahead of time, they might even post them before the show.

Its not a pipe dream.  But don't send the resume yet.  When I started, I agreed to modest technican pay, part time, because the grant was so low.

Permanant magnets won't work, because they invariably have field lines going into their faces.  It is the cusp loss from hell.  Don't feel bad ... everybody thinks it must work at first, and WB1 was built that way (it was cheap and easy to try, and made a nice preliminary test device for the basic setup).  Anything with a ferromagnetic core has the same problem.  But a perfect high-temperature (1000 K would be nice) superconducting ring would be ideal ... that could be considered a permanant magnet, in a sense.

I'll try to attach a picture.  Look for the brown burned rings on the magnet surfaces, where the field lines direct the electrons into the face.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 08:01 PM
Quote
M Simon - 11/5/2007  3:15 PM


I still don't  see why permanent magnets wouldn't work - at least for testing p-B11.


Wasn't the Doc comparing permanent magnets to SC magnets, he thought by the time you get a good cooling system on a permanent magnet it ends up being 1.5 m or so. And at 1.5 m, SC could be easily used?

I know M Simon has been advocating not jumping straight to a net power reactor, could an advantage be that at an intermediate level, say 1.5 meters. it would be known that at 1.5 m net power wont occur, BUT, it can be estimated (scaling laws) what should happen. SO build it, and that proves the scaling laws, right?

I mean gee whiz.... if the scaling laws say at size "X" , output will be within one magnitude or less of break even & Doc builds it &  gets within one magnitude or less of break even.... doesn't that put IEC/emc2 into the drivers seat?  I would think so.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 08:06 PM
All right M Simon,  I found your blog early on..... its a good one too.

google Bussard IEC fusion

I come up 3,6,7, & 9
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 08:07 PM
I think he was comparing cooled wound copper solenoids to superconductors.

You and MSimon can go round and round about intermediate sizes.  Whoever forks over the dough decides.  But Bussard certainly would like to skip all the intermediate steps if anyone will let him.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 08:29 PM
OK I get it. The field lines go into the faces instead of around them.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/11/2007 08:38 PM
Here is a patent on a hydrogen cryocooler with no moving parts.

http://www.delphion.com/details?pn10=US04829785

http://www.delphion.com/cgi-bin/viewpat.cmd/US04829785__?MODE=fstv&OUT_FORMAT=pdf
Title: Re: Fusion with space related aspects thread
Post by: Tergenev on 05/11/2007 08:53 PM
Actually, I think the plan proposed by Dr. Bussard to build the two additional small scale studies makes perfect sense. His team has supposedly  demonstrated that the basic theory of wiffle ball shaped magnetic confinement of electrons to form a Coulomb potential well for ionized fusion fuel can be turned into a physical reality. The next step is, I agree, 1) prove the results occurred. The low number of neutron counts means that the experiment needs to be repeated to give better statistical certainty to the results, and 2) play with the field topography. The cube approach is the simplest to create quickly, but other magnet shapes and polygonal field structures may result in even lower electron losses.   Personally, I love the elegance of this system. It has something that the Tokamak has never had . . . a sense of practical reality. The tokamak folks seem to have fallen for the old adage: "If 'brute force' doesn't work, it proves that you're not using enough brute force" :-)  I briefly flirted with a career in fusion physics back in the early 90s. I finished undergrad physics and took the Physics GRE, and even went to talk to the fusion team at UW-Madison . . . my sister was a student at UW, so I was visiting anyway. These guys were so securely in the toroidal containment camp that it struck me as a perfect example of group-think. They didn't seem to acknowledge that there was anything other than DD or DT fusion, and that the *only* confinement approach possible was tokamak. It seemed sad and a bit pathetic, actually. It wouldn't have mattered, though. I doubt that my undergrad grades could have gotten me into many grad physics programs. I had a stupid idea back at CWRU that 'grades' were a bourgiousie concept.   Another point brought up recently: fixed magnets vs electro. It seems to me taht fixed magnets could work, especially in the small scale study setups, but why tie yourself into a system that is so 'hard coded' in terms of field lines? I've read a point that the use of electromagnets might also allow the Polywell design to use one of the tricks of the tokamak world to increase fusion rates: magnetic field pulsing.   Now, in the tokamak world, pulsing the field strengths is used to heat the plasma, but it wouldn't work directly in the Polywell system, since the fusion specie are not being contained by the magnetic field, but rather by the electrical potential well created by a virtual grid of localized electrons. But it seems possible to me that pulsing the magnetic fields could be used to indirectly pulse the density of the electrons in the well, thus indirectly pulsing the field felt by the fusion ions.  I don't know. This is a refinement that will be studied after the basic approach is re-created by other research teams, I have no doubt.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/11/2007 08:55 PM
Hey, just had a thought about superconductors and the mechanical supports for the polywell.

Question, what is the thermal conductivity of a superconductor?

I'll have to research this one, but I remember from a Larry Niven novel that superconductors, superconduct heat as well as electricity.  Is this true?  If it is, then may I propose the following.

Make the mechanical supports insulators and hollow.  Have a continous superconducting wire that goes from outside the vaccum chamber through the support insulators and forms a coil in the MaGrid.  Than the wire continues through another mechanical support and back outside the vacuum chamber forming a continuous loop.

Put most of the mass of the superconducting "loop" outside of the vacuum chamber in a LN bath where it is easy to cool.  This would seperate the cooling equipement from the Polywell so you don't need as much stuff
inside of the confines of the vacuum chamber.  It also greatly reduces the flow of cooling fluid into and out of the MaGrid.

Of course this only works if the thermal conductivity of the superconductor is really high or infinite.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 08:56 PM
Quote
Tom Ligon - 11/5/2007  4:07 PM

  But Bussard certainly would like to skip all the intermediate steps if anyone will let him.

I certainly see the Docs point, sort of....do I build a device with a 2 meter magnet or a 3 meter magnet. Not a heck of a lot of difference, if you're the guy building the device.

Sidebar: I have nearly 800 views total on the videos. Up dated links for my videos

IEC Fusion for Dummies

http://www.youtube.com/watch?v=XiHsSAS_SQw

Alternate source for for IEC Fusion for Dummies, downloadable in wmv format too:

http://fogerrox.blip.tv/file/223363/

IEC Fusion vs Tokamak Fusion

http://www.youtube.com/watch?v=rBfsq80EgOs
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/11/2007 09:32 PM
Just did my research and found this on wikipedia.  ( I know it's a horrible source )

Many stories attribute additional properties to their fictional superconductors, ranging from infinite heat conductivity (ie thermal superconductivity) in Niven's novels (real superconductors conduct heat poorly, though superfluid helium has immense but finite heat conductivity) to providing power to an interstellar travel device in the Stargate movie and TV series.



Well, that blows that idea, it was nice while it lasted.  I guess the best method of cooling would be fluid flow.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 09:40 PM
Tengenev,

Sound's like you've about got it, except the permanant magnets.  Check out FogerRox's video and the field lines, then sketch in what they would look like with donut magnets.

I know Dr. Bussard wants to run the device continuously or quasi-continuously.  But if problems arise, such as fuel contamination by hydrogen, it might be necessary to periodically ease off the field and dump the ions to clear the contamination.  Something like this might also be used to avoid the Paschen breakdown problem, although I think that can be beat in other ways.  Look at the wiffleball figures a couple of pages back ... one of those modes is varying B field.  There are possible reasons to modulate B to affect how the device starts up.

For these DD tests, neutrons are the key.  Proving you made 'em is everything.  There are some alternative test methods that could be used to do this.  

All of the electronic counting methods raise the possiblity of false counts, particularly if high voltage is arcing, so naysayers can always fall back on that.  I don't know for sure if the counters were left as I set them up, but you could have struck lightning beside them when I was done with them and not gotten a false count, and background was down to a few counts per minute.  But the question can always be raised.  The electronic counters do show just when each count occurs, compared to the other parameters, and clearly show WB6 made neutrons just when the well hit the right depth and fuel ionization ensued.

In the early days, I couldn't get enough neutrons for neutron activation, but that's an elegant method.  Indium foil in a moderator has a huge epithermal resonance capture peak ... fast neutrons will activate it and it decays fast, so a GM counter showing a decay of indium is proof positive of a neutron flux and can't be explained by arc counts.

There are bubble dosimeters available that detect fast neutrons.  You examine a gel before and after a test to see if more bubbles formed.  I picked that trick up from Thiago Olsen, the latest high school student to hit the national news making fusion.  The amateurs are on top of this stuff.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/11/2007 10:04 PM
BarryKirk,

Yes, I remember that room-temperature superconducting cloth from Ringworld.  Niven is supposed to be at ISDC ... I'll have to ask him where to get some!

Looking up superconductivity on Answers.com, I find

"Ordinarily a large electrical conductivity is accompanied by a large thermal conductivity, as in the case of copper, used in electrical wiring and cooking pans. However, the thermal conductivity of a pure superconductor is less in the superconducting state than in the normal state, and at very low temperatures approaches zero."

http://www.answers.com/topic/superconductivity

MSimon, yes, insulators do tend to build up a glaze of sputtered material.  It always looks like it could cause a problem, but does so surprisingly rarely.  I suspect the problem tends to be self-correcting ... as soon as it starts to happen it burns off.  I have been known to clean alumna insulators by a glow discharge method.  I forget exactly what I did on one machine, but I stumbled on a method that tended to get them remarkably clean and white again.

The amazing thing was watching perfectly clean insulators raise havoc, when placed in a high-energy near-neutral plasma.  They apparently act as catalysts for recombination of electrons and ions that would otherwise stay apart.  (Come to think about it, that may have been the insulator cleaning method.)

I could sometimes clean sputter off with muriatic acid, but often some is in too deep.  This even happens in glass windows.  If the material hits hard enough, it is not just sputtered, it is ion implanted, and it can sometimes go in a significant fraction of a millimeter.  Fusion products will probably be even worse.  Nothing in these machines will last forever.

Whoever asked about charging support wires negatively to avoid attracting electrons ... they are supporting a highly positively charged grid, so that's a problem.  
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/11/2007 11:11 PM
Photo Sharing and Video Hosting at Photobucket

Click to enlarge.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/11/2007 11:18 PM
I wonder if the faces of permanent magnets could be covered by a coil? That might reduce current required. However, I'm not a magnet expert. Maybe I could get Indrek to do a simulation.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/11/2007 11:45 PM
I think a refrigeration compressor will consume as much energy as it is required to remove.  So if you need to remove 20%, you will also need 20% more to power the compressor.  So Bussard's EDF reactor system efficiency is down to 60%.  But like you say, love to get to the point where too much power is the problem.

Also, wouldn't fast helium ions be easier to detect than neutrons?  If so, then go straight for p-B11 fusion, don't bother paying for neutron sheilding cause you won't need it, and you can locate your facility anywhere.  The p-B11 fusion is something else that can be proven with a small machine, and while your at it, develop the power conversion technology as an extension of the Helium ion detectors.

If labor is the biggest expense, why would the big 3-meter radius machine cost $200 million?
Title: Re: Fusion with space related aspects thread
Post by: braddock on 05/11/2007 11:52 PM
Are there patents pending on the Bussard fusion technique?  

It has been almost a year since Bussard went "public", which means the clock is ticking if no applications have been filed.  I have seen no disclosure of "patent pending".  I see no filings from the Navy work...no relevant filings from Dr. Bussard since 1989 or so.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/12/2007 12:02 AM
Semper,

I prefer an honest approach to cooling.  Pumped cooling is OK for air conditioners, and science fiction craft operating in the photosphere of the sun.

Some in the field might have the knee-jerk reaction that "neutrons are proof of fusion", due to never having seriously considered p-B11 as credible.  Some re-education may be required.

But yes, it should be straigthforward to measure alphas.  To make it convincing, the measurement needs to include kinetic energy.  There are various methods out there.  A collector plate with a repeller grid in front of it charged to repel anything with less than about 1 MV (2 MeV for a charge of +2) ought to be a pretty convincing detector, and is the energy collection system in miniature.

I always put a residual gas analyzer on a system (a $4000 mass spectrometer designed to detect leaks and outgassing).  It would take a very high reaction rate to make detectable helium on the RGA, but we want a very high reaction rate.

I would construct a p-B11 demo reactor with the option of running DD if possible.  Risk mitigation.  A machine with a serious chance of burning p-B11 ought to simply clobber DD.  If the program ran into some unforseen problem with the more ambitious fuel, the fallback could be the difference between failure and still achieving net power.  But it will be too big to move easily.  A location where either fuel is permissible offers this advantage.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/12/2007 12:24 AM
What do you mean by "an honest approach to cooling" ?

Would Helium ion detection work with small reactors like WB-7 or WB-8 ?

And why does the cost scale up so high for the Demo reactor?  Is it just more people and more years to build it?

Also, has anyone at JP Aerospace expressed interest in combining their "Airship to Orbit" project with Bussard's fusion system?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/12/2007 01:44 AM
Quote
SemperUbiSububi - 11/5/2007  8:24 PM

What do you mean by "an honest approach to cooling" ?

Would Helium ion detection work with small reactors like WB-7 or WB-8 ?

And why does the cost scale up so high for the Demo reactor?  Is it just more people and more years to build it?

I'd guess that any any scale Helium ion detection would work. Re: Cost, yes, when you scale up from a one foot device to a 9 ft device it appears to me just the cost of materials go up, significantly, as well as safety concerns, and thusly safety remediation. A vacum chamber for WB6 cost 200k, scale that up 9 fold..ouch.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/12/2007 03:32 AM
If labor is the biggest expense, why would the big 3-meter radius machine cost $200 million?

Custom designed, custom built parts.

Mistakes. Unforseen problems.

========

Refrigeration requirements are determined by

1. Heat load - the amount of joules per second to remove - smaller is better
2. The delta T  - the difference between the cool side where you are extracting heat and the hot side where you are rejecting it - smaller is better
3. The absolute temp of the cool side - higher is better

It is in effect Carnot in reverse.

Going from 4K super conductors to 77K superconductors is a big help.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/12/2007 03:49 AM
I'd guess that any any scale Helium ion detection would work. Re: Cost, yes, when you scale up from a one foot device to a 9 ft device it appears to me just the cost of materials go up, significantly, as well as safety concerns, and thusly safety remediation. A vacum chamber for WB6 cost 200k, scale that up 9 fold..ouch.

Except the scaling is not linear.  It is more like 3rd or 4th, possibly 5th power. The reason is that the bigger you go the fewer places have the eqpt to make it. Plus the eqpt has a lot of down time because we are not talking production items. Either that or you have to get in line. i.e. long lead times.

The pumping requirements scale up as the 3rd power for equal pump down times.

A 1 MW reactor is going to cost 1/10th what a 100 MW reactor costs. Such a reactor might not even get you to break-even. It would definitely tell you if break even is possible.

Here is how I would step it:

100 MW
1 MW
10KW
100W
WB-7 & WB-8

Which is the kind of stepping that the fission guys went through. Dr. Bussard should be familiar with all that because of his work on the early nuke stuff.  Each step is a doubling of size (roughly).

The nuke program of the early 40s was building reactors at a furious pace.

The reactor built in Chicago, CP-1, was started up at .5 watt. Later increased to 200 w max. They had two problems - shielding and cooling. Which is why the reactor was moved from Chicago to Argonne (south of Chicago).

BTW I will be visiting U Chicago on June 8th to 10th for my son's graduation.  When I visit I always make a point to see the Moore sculpture about 300 ft or so from where the pile was built.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/12/2007 04:03 AM
Tom,

Wouldn't a mass spectrometer on the exhaust work for helium detection in a 100MW p-B11 unit? You should get about a half pound to a pound of He per day output.  

I do think that you are going to have to do D-D at the lower power levels as proof of the pudding.

At equivalent power (thermal) you are going to get a whole lot more neutrons from D-D than you do from fission.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/12/2007 04:05 AM
Quote
M Simon - 11/5/2007  11:49 PM

Except the scaling is not linear.  It is more like 3rd or 4th, possibly 5th power. .

I was expecting it to be logarithmic, (thats the right word, right?) but I wasn't sure.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/12/2007 04:14 AM
The word you are looking for is exponential.

Logrithmic implies a cost that goes up slower than the volume.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/12/2007 05:45 AM
Quote
M Simon - 11/5/2007  12:14 AM

The word you are looking for is exponential.

Logrithmic implies a cost that goes up slower than the volume.


Did I mean algorithmic?

SO If I 2x the size of a pipe, I get 4x the volume of water, thats an algorithmic increase?

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/12/2007 05:59 AM
That is an exponential increase. The exponent is 2.

However, it is also an algorithmic increase since there is a mathematical function that describes it.

The general rule is that big stuff costs more. That is a rule of thumb.

Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/12/2007 08:18 PM
Whoever asked about charging support wires negatively to avoid attracting electrons ... they are supporting a highly positively charged grid, so that's a problem.

Oops, I forgot about that.  Doh!
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/12/2007 09:03 PM
I was watching the google video again, Doc says WB7 & WB8 will be 3 to 5 times better, but doesn't really quantify the improvement. Does anybody know how these are better?

http://video.google.com/videoplay?docid=1996321846673788606&q=bussard++IEC+fusion
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/13/2007 07:00 AM
Tom,

Will this type of technology play a role in the pilot fusion power plant?

http://en.wikipedia.org/wiki/Mercury_arc_valve
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/13/2007 08:15 AM
Quote
Tony Rusi - 13/5/2007  3:00 AM

Tom,

Will this type of technology play a role in the pilot fusion power plant?

http://en.wikipedia.org/wiki/Mercury_arc_valve
I think Telsa used them at his Niagra falls station

http://www.answers.com/topic/war-of-currents
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/13/2007 11:30 AM
Toni,

It will be done with silicon or silicon carbide. The Device is called an SCR.

http://en.wikipedia.org/wiki/Silicon_controlled_rectifier

You just about can't make anything with quantities of mercury any more.

For AC to DC conversion rectifiers (diodes) are used. Again silicon or silicon carbide.

http://en.wikipedia.org/wiki/HVDC

http://en.wikipedia.org/wiki/Powerline_Ekibastuz-Kokshetau

http://en.wikipedia.org/wiki/HVDC_Itaipu
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/13/2007 05:22 PM
M Simon,

In the Google talk, Bussard kept on emphasizing how we are going to have to reeducate an entire generation of electrical engineers in the technology of the 1930's, gaseous electronics. I have always wondered what he was getting at. Maybe it was this??

http://www.tigercom.dsl.pipex.com/gallery.htm
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/13/2007 11:33 PM
Tony,

That is some real cool stuff.

The stuff Dr. Bussard is doing is more like vacuum tube stuff.

What you might want to look at is beam power tubes where a virtual grid is formed, for the same reasons Dr. Bussard wants a virtual grid - to control losses.

http://www.tpub.com/content/neets/14178/css/14178_102.htm

I'm very fortunate to have grown up in the vacuum tube era. Including working with high power transmitting tubes (50 KW) @ 100 MHz (FM xmtr).
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/13/2007 11:57 PM
Good general stuff here  about vacuum tubes.

The bit on cooling is especially good.

http://en.wikipedia.org/wiki/Vacuum_tube
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/14/2007 12:02 AM
Tungar Rectifiers are neat tubes

A picture here:

http://www.electricstuff.co.uk/mercarc.html

Along with the circuitry for some of the tubes in the earlier link re: mercury tubes.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/14/2007 12:14 AM
Really good beam power tube drawing:

http://www.allaboutcircuits.com/vol_3/chpt_13/5.html

*
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/14/2007 12:36 AM
Sheesh!  I go up to the cabin for one measley weekend, and the board explodes!

MSimon, you wondered if a mass spec would detect helium.  The EMC2 chamber had an SRS RGA100 residual gas analyzer, which is a quadrupole mass spec capable of looking at M/q of 1-100.  It is available with an optional electron multiplier detector which will get the sensitivity down to about 1e-14 torr.  As long as the device creates helium at a rate sufficient to cause that partial pressure, and there is no background gas to interfere, it would do what you say.

That method is useless with deuterium fuel, where you would not be able to distinguish helium 4 from D2, or helium 3 and tritium from HD.  But for those reactions, you have distinctive neutrons with characteristic high energies.

If I have anything to do with it, any high vacuum system I ever work on from now on will have an RGA.  Marvelous little gizmo, and not very expensive these days.  They detect leaks, they detect outgassing, and they tell you if the fuel species are being diluted by evolved gas.  We could also see the transition in background gas from H2 to HD as the number or runs progressed, evidence of the rate at which we were ridding the interior surfaces of hydrogen and managing to diffuse D in to replace it.

The closest thing to vacuum tubes being taught today is a field called "gaseous electronics".  Practioners of that field may have jobs in IEF, but they'll need some remedial education in fusion physics.  

I started out with vacuum tubes, so these machines made sense to me.  It also helped that I did undergrad research on time-of-flight mass spectrometers, so I knew about accelerating grids and kinetic energy of ions.  The instant I learned that fusion researchers used electron volts as their "thermometer", I started to wonder why they were using heat instead of electrostatic acceleration.  Within a day or so, I had dreamed up the fusor.  My profs said it could never work, so I never pursued it.  But the approach always made sense to me, and the day I met Dr. Bussard, I understood the basics and knew I wanted to be a part if his work, whatever it took.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/14/2007 01:07 AM
Here are some more magnetic pictures from Indrek.:

http://www.mare.ee/indrek/ephi/polywell_cube_bfield_lines.jpg

http://www.mare.ee/indrek/ephi/polywell_cube_bfield_lines_logcolor.jpg

Solenoid test:

http://www.mare.ee/indrek/ephi/test6_lines.jpg

From the IEC Fusion Newsgroup:

http://tech.groups.yahoo.com/group/IEC_Fusion/

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/14/2007 02:27 AM
Question:
Re: WB7 & 8....
Could a 12 magnet device close down the cusps/b fields to the point where electrons would not circulate?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/14/2007 03:10 AM
FogerRox,

The models do not indicate that the dodec will totally choke off recirculation.  The truncated cube is described as making a "quasi-spherical" trap.  The dodec should be less quasi, more spherical.  I would expect it focusses the electrons ions better in the center.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/14/2007 03:27 AM
Thanks Tom.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/14/2007 04:29 PM
Hopefully we'll get to build the WB-7 and find out for sure soon.  I'm curious: have more-sided polyhedrons been modelled?  At the smaller prototyping size, I assume we hit diminishing returns pretty quickly, but I wonder how true that is at larger sizes, such as might eventually be envisioned for p-B11 reactions or nuclear waste disposal.

It's interesting how little credence was placed in electrostatic confinement regimes, and how little progress other IEC efforts made.  Was the gridless IEC scheme really that big of a quantum leap in philosophy?

Thanks Tom and Simon for posting; this and the Yahoo IEC forum are invaluable resources for those semi-technical people like myself trying to get up to speed on Polywell.


Quote
Tom Ligon - 13/5/2007  10:10 PM

FogerRox,

The models do not indicate that the dodec will totally choke off recirculation.  The truncated cube is described as making a "quasi-spherical" trap.  The dodec should be less quasi, more spherical.  I would expect it focusses the electrons ions better in the center.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/14/2007 07:00 PM
Re: plant efficiency.

A nuke running at full power converts about 40% of the power generated into electricity. The rest goes into heat.

In the beginning stages it may be useful to just forget about waste heat recovery from D-D. Water cooling or cooling towers are in order.

If you could reject the waste heat at 80 deg C or higher the cooling towers could be much smaller than you see at nuke plants.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/14/2007 07:02 PM
Talldave,

The MaGrid or Gridless scheme is a huge difference is capability.  Orders of magnitude difference.

The problem with grids is that they absorb electrons.  Every time an electron impacts on the grid it gets absorbed.  More importantly, the electron contains a lot of energy and the energy used to create that high
energy electron is absorbed.

Since, the average electron makes well over a million pass through the system for each fussion event.  The grid will absorb many electrons for each fussion.  Those lost electrons represent a huge energy loss for the system.  This makes a grid based system a net power loss.

In a MaGrid system on the other hand, the electrons can make millions to billions of passes through the system before it impacts on anything.  This cuts down the energy losses by many orders of magnitude.

Since net power is energy of fussion - power loss

and the grid represents virtually all of the power loss in a grid based system.  A MaGrid based system has the potential of a power loss less than the energy of fussion making net power production a possibility.

A grid based system cannot be a net power producer.
Title: Re: Fusion with space related aspects thread
Post by: RabinaHarjar on 05/14/2007 07:09 PM
My first post here!

I see there are a lot of speculation on how to fund research on this thing. It shouldnt be that difficult. Neutrons=money. Publish the blueprints of the WB-6 apparatus complete with a comprehensive description of how to build it and how to run it. Preferrably in downloadable PDF-formate. Once independent workers have achieved that 0,4 millisecond neutron signal that was claimed by mr Bussards team further scepticism should be gone. Funding will then most certainly take place on a grand scale.

Independent repetion is the lithmus test any technical or scientifical achievement has to withstand. Normally, new scientific results are published in peer-reviewed journals and thus subject to the scrutiny of the scientific community. If someone instead chooses to announce his claims in an online lecture, it will certainly evoke some disbelief.

To say the least.



Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/14/2007 07:27 PM
M Simon,

Maybe you can get the diameter of the wire in WB-6 and number of turns from Tom Ligon or the Doc himself and do a real simulation of the actual magnet configuration.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/14/2007 07:39 PM
Quote
TallDave - 14/5/2007  12:29 PM

 I'm curious: have more-sided polyhedrons been modelled?

IIRC Doc Bussard, in his google talk, said 3 to 5 times better, in reference to a truncated cube & dodecahedron (WB7&8). Which made me wonder if a sphere with say.... I dunno... say 40 or so,  magnets would cut down the cusp losses/recirculation and how beneficial that would be. I'm guessing better electron control leads to better confinement and different potential well properties.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/14/2007 07:56 PM
I suspect you get into diminishing returns.  The advantage of more faces is probably primarily better central focus.

Leaks out the cusp holes are not really losses, due to the recirculation.  Losses only occur if an electron hits unshielded anode surface, or if it eventually loses kinetic energy.  Improving the relative concentration of electrons inside the wiffleball versus outside the magrid is beneficial, and is largely a function of reducing the effective cusp hole size, but at some point good enough is good enough.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/14/2007 08:19 PM
The more faces their are,  the more magnet area is potentally in the path of electrons.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/14/2007 09:28 PM
Quote
Tom Ligon - 14/5/2007  3:56 PM

 but at some point good enough is good enough.

I gotcha. But if. one didn't have to worry about electrons going outside the wiffleball, is there a gain here, with a respect to engineering?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/14/2007 10:29 PM
The higher the Gwb (wiffleball factor), the fewer electrons get outside.  Reducing the outside electrons is good from the standpoint of reducing the tendency to create a Paschen discharge.  Since Paschen discharge ended all the runs of WB6, that's plenty important.  But the overall trapping of electrons is probably not improved much ... the Gmg (magrid recirculation) makes up the difference.

Higher magnetic field strength should improve electron lifetimes ... power gain goes as B^4R.  I have little doubt a very large part of that is the reduction in drive power requirements to make up lost electrons when higher fields are present.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/14/2007 11:25 PM
Nice vacuum primer:

http://www.abbess.com/vac/datasheet-vacbasics.html
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/14/2007 11:51 PM
Check out this link:

http://www.fusor.net/board/view.php?bn=fusor_introductions&key=1179183175

Looks like John Carmack, the creator of Doom and Quake and one of the leaders in the suborbiltal flight enterprise got interested in Dr Bussard's work
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/15/2007 01:37 AM
John Carmack - Now there's a man who knows how to spend his weekends.  He has lots of experience programming computers to control rocket engines.  I bet he'd be seriously good at setting up the gas injection and power controls for Bussard's fusion reactor.

Gotta envy a man with money!  Especially one who uses his money to develop expertise.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/15/2007 01:45 AM
Thanks!  He contacted me at work a few weeks ago, but I apparently failed to forward the message home.

Armadillo will be bringing some toys to ISDC.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/15/2007 02:25 AM
Has Dr. Bussard been approached by the Canadian government?  There are considerable numbers of "green" initiatives going on north of the border.  What about the EU?
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/15/2007 03:22 AM
Quote
M Simon - 14/5/2007  6:25 PM

Nice vacuum primer:

http://www.abbess.com/vac/datasheet-vacbasics.html

Nice article, but a little dated on some of the pump technology...

Having seen the results of more than one oil pump failure I can not say enough bad things about them. A more modern technology is the dry scroll pump ( Google Varian ). They are great, will get you into the milli torr (10^-3) range, and if they fail you don't have to worry about oil spraying back and coating (ruining)  the chamber.

They also left out cryo pumps. These pumps work by cooling a carbon trap to about 15K with helium coolant. They will start pumping at a milli torr (10^-3) (meaning you need a boost pump like a dry scroll or an oil or a diaphragm pump that you isolate after you drop below a milli torr) and get you in the 10^-6/10^-7 range. They are a bit tricky to work with, to much O2 building up in the carbon trap can lead to a catastrophic failure when the pump is regenerated. Exposure to anything above a milli torr will require regeneration and can lead to nasty failures inside the carbon trap. They also do not work well with processes that involve H2 and helium since neither will freeze out.  

And the pump I am in love with. I recently have had a few projects where we bought these cute little compact turbo molecular pumps with an integrated diaphragm booster pump and integrated controller and vacuum sensor. The maker escapes me right now, but no more complex valve controls, extra software for switching opening and closing pump valves while starting and stopping pumps and purge lines. It is just one neat little package with two buttons (pump, vent) and a vacuum gauge that automatically switches from the thermocouple gauge to the cold cathode gauge. Easily reached 10^-6. They are simple to integrate (one vacuum flange, an N2 purge line to the pump for venting and an exhaust pipe). They capture  the energy of the turbo molecular turbine spinning down to safely vent the chamber in the event of a power failure. Just gorgeous.

One word of caution about cold cathode gauges, they produce a decent magnetic field and generate a noticeable glow that may throw off light sensing detectors inside a chamber. I know with the integrated turbo molecular we had to actually work with the manufacture for a method to override the automatic cold cathode gauge.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/15/2007 03:57 AM
Armadillo has some cool video at their site:

http://armadilloaerospace.com/n.x/Armadillo/Home
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/15/2007 04:01 AM
I do love turbopumps.  That big chamber at EMC2 had 6 Leybold TMP 1000 turbos, at least two of which had cold traps associated with them (dramatically reduces water vapor pressure).  Add two big forepumps with Roots blowers, and assorted traps.  The chamber could easily run at half capacity, a design feature to keep it up when pumps needed repair.

The big opening at the back end was there in case they decided to add more capacity, like maybe a big old cyropump.
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/15/2007 12:36 PM
Tom, no one has comment on how hard a vac you need to pull. Is 10^-5 good enough, or do you have to get down to the 10^-9 level?

For an operational fusion plant would you need a cold trap? I would think the heat generate inside the wiffle ball would bake out the chamber (pull the water vapor/oils right out of the chamber walls).

I have wondered what all the H plasma and He byproducts would do to the vac over time. I know enough to know it would mess with a Cryo ...
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/15/2007 12:45 PM
Thanks for the link,  that is too cool John Carmack interested in IEC fusion.  Everything this man touches turns to gold.

In a few years we may see a fusor powered versions of Pixel and Texel... Ah the anticipation.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/15/2007 01:37 PM
I know that chamber, cold and at rest, could pull 1e-8 or better on one turbopump.  The goal was around 1e-9 torr.  That does not mean the pressures were that low during experiments ... 1e-5 was probably more typical, and pressures during Paschen discharges probably spiked above 1e-3 torr.

You do want the background pressure low so that the deuterium you introduce is not diluted, and because background neutrals are energy-robbers and set you up for Paschen discharge.  Also, most electron emitters work best at low pressures, and may quit working above 1e-5 torr.

I suspect the machine would have benefitted from less dead volume (the tank was much longer than its diameter to allow for the possibility of additional apparatus that was never used), and more pumping capacity.  We got the pumps at half price, but they normally run about $25k each, and there were 6 of them.  To drop the pressure an order of magnitude by pumping would take 10x the capacity ... 60 pumps!  We had the tank electropolished to reduce outgassing an order of magnitude, which was well worthwhile, but does nothing to deal with neutrals released by the energetic physics going on.

Dr. Bussard now has data showing how much gas needs to be dealt with, so future efforts should be better able to anticipate pumping requirements.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/15/2007 04:02 PM
New magnetic field photo.

Also Indrek has some questions about magnetic fields. Runge Kutta and other stuff. :

==

I need a comment in regards to magnetic fields.

I thought about visualizing individual lines of the b-field
and tryed to do it by simply integrating a line over the
vector-field.

The z component of the b-field on the given intersected plane
at the middle of cube polywell is 0 so I saw no problem
with that approach. What I found is that the integrated
field line forms a vortex.

You can see a picture here with 8 line integrations:

http://www.mare.ee/indrek/ephi/polywell_cube_lint.png

Or a segment of a line:

http://www.mare.ee/indrek/ephi/polywell_cube_lint_segm.png

I'm using fourth order Runga-Kutta method, decreasing the
step size by a thousand or increasing the accuracy of the
magnetic field calculations by decreasing the step there
did not bring any changes to the resulting path.

Is this normal?

Regards,
Indrek

===

You can answer him here:

IEC Fusion Newsgroup

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/15/2007 10:46 PM
If John Carmack builds a fusion reactor I hope he posts it on his website like he did with his rocket projects.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/15/2007 11:54 PM
Couple more papers posted on the EMC2 website.
Title: Re: Fusion with space related aspects thread
Post by: nacnud on 05/16/2007 12:41 AM
Link please :)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/16/2007 12:43 AM
http://www.emc2fusion.org/
Title: Re: Fusion with space related aspects thread
Post by: nacnud on 05/16/2007 12:48 AM
Thank you, googleing EMC2 wasn't helping.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/16/2007 02:15 AM
Quote
M Simon - 15/5/2007  7:43 PM

http://www.emc2fusion.org/

Should the photo on the right be captioned "electron losses?"  (Although controlling election losses would be a valuable technology too.)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/16/2007 04:06 AM
Funny. Never noticed that.

BTW you should correct the url in your post. Something funny happened.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/16/2007 07:26 AM

Quote
M Simon - 15/5/2007  7:43 PM

BTW you should correct the url in your post. Something funny happened.

Some extra html got in the way, the guilty party  looks to be "/div" but with the greater/less than symbols,><.

Quote
TallDave - 15/5/2007  10:15 PM
Should the photo on the right be captioned "electron losses?"  (Although controlling election losses would be a valuable technology too.)

Doesn't the caption say "Fusion and control of electron losses" ?
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 05/16/2007 03:20 PM
For what it's worth, I've just made my first donation to Dr. Bussard's work.  It's important, and from the recent Space Show interview it's clear that they still need funding.  So I've chipped in $50.  That's in the "mildly painful" range for me, but well worth it given the civilization-changing nature of this technology if it works.

The donation process is quick, simple, and clear.  I urge you to contribute what you can; just click the Donate button at http://www.emc2fusion.org/ .

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/16/2007 04:18 PM
Thanks!  I'd rate that in the generous category, on a scale of contributions most folks might consider.

It is looking like the ISDC trip, my present contribution, is likely to take about $1100.  That was beyond ouch, money my wife would have had a cow over.  I'm using my projected writing income from two recent sales, mine to spend as I please.  

Dr. Bussard is probably running a lot out of pocket.  I know he supported the company to the tune of $30 k, plus no salary, during one dry stretch in the 90's, and may well be doing it again.

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/16/2007 09:24 PM
Joe thanks for putting your money where your mouth is! I wish I could do the same. I have some issues to take care of first.

I went to the Seattle area NSS business meeting last night. We were talking about terraforming mars and finding earthlike planets. The most recent planetary find was "only" tweny light years away! I asked Dr. Bussard recently how fast one of his QED fusion rockets could go, if it existed. He said between .1 and .3 c. So if it could do twenty percent of the speed of light it would take around 100 years to reach this planet. Bussard estimates that it will take at least 3 billion dollars and fifteen years to build this rocket, plus 5 years and 200 million just to build the fusion power source. So we are likely 120 years away from ever getting there, even if we started a crash program today, which seems unlikely.

It got me asking myself, just how much of the universe we can actually see from earth? We all have heard about dark matter and dark energy making up the missing mass in the universe. But what if that missing mass was just "really small stars" and "really small planets" and planetesimals, that we can't see with our current telescope technology?

Just how small can a star be anyway??? I went to ask dot com. And I found two interesting links.

http://hubblesite.org/newscenter/archive/releases/1994/54

This site had a picture of a star ten times smaller than our sun, and 60,000 times fainter.

http://www.newton.dep.anl.gov/newton/askasci/1995/astron/AST163.HTM

This site said the smallest star, a white dwarf, is about the size of mercury.

But is there a natural lower limit? And what is the limiting factor?

The europeans have a device at CERN, the Large Hadron Collider, that they hope to make mini-black holes with. My question is, if you feed them enough mass, at a fast enough rate, can those mini-black holes be turned into mini-stars?

Maybe we are missing alot of "really really small" stars, with really small goldilocks regions of habitable temperature, alot closer to us than we realize, because our telescopes are not good enough to pick up the faint light from them.

Just a thought.


Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/16/2007 11:53 PM
Sorry Tony,

Stephen Hawking discovered that black holes evaporate, the smaller they are, the faster they evaporate.

A black hole with the mass of Mount Everest would decay down to nothing in about 1 second.

We couldn't feed a black hole made by the LHC fast enough.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/17/2007 12:33 AM
Tony,


There may be a technology out there that would allow flights to the closest stars in a matter of weeks.
There was a German scientist named Burkhard Heim, who extended Einstein’s work and come with very interesting ideas of space travel. He got a lot of publicity in the 1950s and Wernher von Branun even approached Heim about his work and asked whether the expensive Saturn rockets were worthwhile.
Heim died forgotten in 2001, but his ideas are gaining popularity, especially since Martin Tajmar working for the European Space Agency discovered an unexplained electron behavior that was predicted by Heim Theory.

Check out the following links:

http://www.newscientist.com/channel/fundamentals/mg18925331.200-take-a-leap-into-hyperspace.html

http://news.scotsman.com/scitech.cfm?id=16902006

http://english.pravda.ru/science/tech/16-02-2006/76045-0
 
Title: Re: Fusion with space related aspects thread
Post by: coach on 05/17/2007 01:18 AM
pbelter, There is a thread (not near as long as this one!) about Heim's Theories in Advanced Concepts that may need to be resurrected.  Have you been there?  

http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=7678&start=1


Coach
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/17/2007 01:49 AM
No, I haven't been there, but looks like Tom has.
The major discussion on this topic is at http://forum.physorg.com/index.php?s=c20b23fd691db5016741560bab3e6032&showtopic=4385&st=1440
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/17/2007 10:31 PM
Peter,

I am familiar with Heim Theory only to the extent that I have read all the recent articles, and the AIAA paper. I don't pretend to understand it. I hope someone makes some headway with it to build a practical advanced propulsion system. I hope that ASU teacher, Pavlos Mikellides, is doing something with it. But what I have found to be true in the new space biz is, you have to do things yourself if you want anything to get done.

What I was trying to get at is, I don't know any laws of physics that say a gravity driven mini-star is not possible. A self-luminous "moon" the size of mercury placed into orbit at the right distance around Mars might warm it up enough, and soon enough, to make it habitable in the next century. But I am no expert on this subject. It was just a  thought experiment.

How does this relate to the Bussard device you ask? Well if you take Bussard at his word, he knows all the science required to start a controlled nuclear reaction. He knows how to light a mini-star, so to speak. Now we just have to find the right near earth crossing object with enough hydrogen and boron on it, (or other fusionable material) and park it around mars, and light it. But Dr. Cramer thinks it will have to be more massive than Jupiter. I would contend that smaller stars are possible. We have made them. We call them hydrogen bombs, and they have very short lifetimes. The trick is going to be in the type kindling used after you light the match! I think the current theory is that stars burn (fuse) all elements, up to iron, before going out or going nova. I have always wondered why stars stop at iron though!

I asked several experts the same question last night. I got this letter back from Dr. Cramer. He has written several science fiction books like Twistor, and is still a physicist at the University of Washington, I believe. Anyway here is his letter.

Dear Tony,

    This is more a question for astronomers than physicists, but let me give it a try. As your references indicate, the question is ambiguous.  You are presumably not asking about neutron stars or black holes or large planets, but about self-luminous stellar objects.  Even then , there are really several questions:
How small can the mass of a self-luminous stellar object be, assuming that it is still on the Main Sequence, i.e.,still in the hydrogen-burning stage?
How small can the radius of a self-luminous stellar object be, assuming that it is still on the Main Sequence, i.e.,still in the hydrogen-burning stage?
How small can the mass of a self-luminous stellar object be, assuming that it is off the Main Sequence, i.e., it is a "burned out"star that is the remnant of a stellar collapse (but not a supernova)?
How small can the radius of a self-luminous stellar object be, assuming that it is off the Main Sequence, i.e., it is a "burned out"star that is the remnant of a stellar collapse (but not a supernova)?
    For questions 1 and 2, the object, (assuming more or less solar system metallicity)  must be somewhat more massive than Jupiter (~0.001 solar masses) but could be much less massive than our Sun.  An Arthur C Clarke novel (was it _2010_?) envisioned a scenario in which Jupiter was pushed over the edge and became self-luminous, suggesting to me that a star of a few Jupiter-masses might be self-luminous.

    For questions 3 and 4, the object would probably be a brown dwarf of very low luminosity, and therefore difficult to observe unless it was close.  Further, the size limits would depend on the metallicity of the star and the amount of hydrogen that remained.

    Given a specific scenario about the star's history and composition, one could probably run stellar dynamics simulations that would answer the questions above, but I do not know who does such things.

    Are you implicitly asking about the conditions for habitable planets around such small stars?  If so, there are problems.  First, low-mass stars tend to be less stable and more subject to massive flare-ups that are likely to be incompatible with life and sustained evolution.  Second, the radius band of the orbital "habitable zone" in which a planet would have a life-sustaining average temperature would be close-in.  This would lead to the cooler sun looming very large in the planetary sky and to tidal forces what would probably tide-lock the planet, so that it always presented the same face to its star companion (like the Moon with respect to the Earth or Mercury with respect to the Sun).  Therefore, the habitable region on the planet's surface would only be in the twilight ring around an equator of the planet.

Regards,
John Cramer
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/18/2007 01:16 AM
Hi Tony,

The Heim Theory is definitely very interesting topic in itself and I hope it works but it is long shot compared to Dr. Bussard's work.

I have been thinking about financing the Polywell concept. Dr. Bussard leaning towards a non profit foundation is rather discouraging as it implies that the invention is not promising enough for anybody to invest their own money in it. If not for Tom's first hand accounts, I would start having doubts myself.
I would definitely like to see Dr Bussard finding private investors or going IPO. If those who trust this technology with their own money are going to get rewarded by getting rich it will encourage other visionary technologies to be funded.
However if private investment is not going to happen, who could sponsor the research? Well, I think those would have to be institutions with a lot of negative publicity that could gain regardless of whether the research works or not. The first company that comes to my mind is the agricultural giant Monsanto that struggle to promote themselves as environment friendly. Fusion would not in any way jeopardize their core business, and the publicity would be good if the project doesn't work or excellent if it does.
The Monsanto Fund is a 'philanthropic arm of the Monsanto Company'  and among their major goals are  'The Environment' and 'Science Education'. In the past they have issued grants up to $1.2 million. The board of directors meets on July 1st to review new funding proposals.
Here is the link to the application form: http://www.monsantofund.org/asp/Qualifications_and_Procedures/PFR_Specs.asp

Another natural sponsor would be the oil companies. They put significant effort into advertising to convince the public how heavily they invest in alternative energy sources. And they should have the money too. I need to do more research on that.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/18/2007 02:07 AM
Congress in its infinite wisdom just removed the tax credit for alternative energy work from the oil cos.

That will punish them!
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/18/2007 02:30 AM
Monsanto is one of the companies I am truly do not like. Their practices promote genetic mono cultures which are inherently unstable plant populations.
Title: Re: Fusion with space related aspects thread
Post by: Tergenev on 05/18/2007 02:35 AM

"The trick is going to be in the type kindling used after you light the match! I think the current theory is that stars burn (fuse) all elements, up to iron, before going out or going nova. I have always wondered why stars stop at iron though!"

Fusion up to Iron is an exo-thermic reaction. (in chemistry terms) or, in other words, they are energy surplus reactions. Beyond iron, fusing elements uses up more energy than it releases. That's why stars go nova when they run out of the lighter elements. The outward pressure of the extra energy created by the energy-positive fusion reactions suddenly stops, and the middle of the star starts sucking energy in instead. The center collapses. The outer shell then collapses on top of it. The only force remaining to stop it from collapsing into a black hole is the repulsive forces of neutrons to one another. If that is overwhelmed . . .BAM, straight down the singularity hole. The result: nova, neutron star, supernova, and/or black hole, depends only on how much mass remains in the star when the iron fusion line is crossed.

 

 

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/18/2007 03:12 AM
Monsanto is one of the companies I am truly do not like. Their practices promote genetic mono cultures which are inherently unstable plant populations.

What do I have to worry about? Plants that go berzerk and attack humans?

Me? I hate the oil companies.

They were selling gasoline last year for less than they are selling it for this year. Why? Obviously they could have gotten a higher price since we are paying it now. They need to be investigated for cheating their shareholders.

The crooks.

=====

In fact I hate all companies that sell people what they are willing to buy at a price they are willing to pay. The rest?  I don't worry about them. They are out of business.

=====

Well if no evil company is willing to put up the money for a project it doesn't understand, whose proponents admit is an iffy deal even if the theory proves out (so far no details on the physics sufficient to convince most sceptics and some proponents) what ya gonna do?

I think we need a million supporters to get the job done.  As much as I hate to say it, this is a job for government.

Going on about Monsanto has just cost us support from that Co and its employees. Oh, yeah. Now we have problems with the oil Cos. Great! Any other potential supporters you'd care to insult?

=====

Me? I'm glad for the oil Cos. and I say a prayer for Monsanto every time I enter a temple of consumption. Otherwise known as a super market.

I hope that fixes it.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/18/2007 03:43 AM
Demo reactor

http://www.youtube.com/watch?v=eeMd5LCu7Ag

Another one

http://www.youtube.com/watch?v=7RVlg8M8XRs
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/18/2007 05:27 AM
I blogged the Popsci  (second url) video here:

http://astuteblogger.blogspot.com/2007/03/helpful-bunch.html

and

http://www.classicalvalues.com/archives/2007/03/a_helpful_bunch.html

The first vid is new to me.

They really need a short voice track or a long explanation for the first one.  And music. Otherwise you have to be in love with the stuff to get it.

Basically I use the videos and pictures as advertising for Dr. Bussards work. My goal ultimately is to get 1,000,000 people to watch the Google Video. And 10,000 of those to either write Congress or write a check.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/18/2007 07:15 AM
Tergenev,

Is it possible for a star to just burn out and not collapse or explode into something else?

Supposedly all the matter on earth has gone through three stars?? or something. How do they know that? Or what makes them think they know that?

I know we have heavier elements on earth than iron. I assume that comes from nova or super nova explosions. But neutron matter is much denser than naturally present elements on or near the surface of the earth. Are elements somewhere in between possible? Would much stronger gravity fields or magnetic fields make them more likely to be stable?
Title: Re: Fusion with space related aspects thread
Post by: Crispy on 05/18/2007 10:04 AM
neutron matter is only possible in the extreme gravity of a neutron star. To overcome the strong nuclear force with relatively weak gravity requires a hell of a lot of it. there's nothing inbetween, afaik. You either overcome the STF, or it wins and you have normal matter.
Title: Re: Fusion with space related aspects thread
Post by: Tergenev on 05/18/2007 10:09 AM

" Is it possible for a star to just burn out and not collapse or explode into something else?"

Yes. But only if the star is so much smaller than our sun that fusion never gets started, or only barely starts. In that case, the light from the star is almost entirely provided by the force of all of that mass falling into that gravity well, but very slowly. This is a brown dwarf and it will likely burn slowly like this for 15 or 20 billion years.
 

If a star is lighter than our sun, by about 50% (an inexact estimate, I don't have the exact number in front of me), it does begin using fusion as its main energy source, and it enters the 'main line' stars. But at the end of its life, when it crosses the iron fusion boundary, the force of its mass's gravity is not enough to cause it to overcome simple electrostatic repulsion (the force of the charges on the protons and electrons pushing each other away). In that case, the star's core does collapse, and the outer shell collapses on top of it. The shell 'bounces' and expands out into space. This is a planetary nebula. The resulting  exposed core is a white dwarf, which like the brown dwarf, just slowly burns up its remaining fuel and fades out. This is the fate of our sun.

Above about 3 times the size of our sun, the mass forces the core to collapse into a neutron star.

Above about 5 times the size of our sun, the mass forces the core to collapse into a black hole.

The most recent supernova discovery found that above 150 to 200 solar masses, the collapsing star can create  a supernova so massive that it basically blows away ALL of its remaining mass. I think they're still trying to figure out the mechanisms for this process, but it is likely that the early universe saw many more of these types of supernovae than we do today, and these may have been tremendous engines of heavy element creation.

Yes, most of the elements heavier than iron were created during the collapse of some star or another, as a supernova releases a huge amount of energy all at once, which is then available to create the energy-hungry fusion reactions that are necessary.

"Supposedly all the matter on earth has gone through three stars?? or something. How do they know that? Or what makes them think they know that?"

A couple of ways. One is a simple statistical calculation of how many of the most common stars in the universe went through their full life-spans during the 13.4 billion years since the start of the present universe. But they think that more massive stars (which lived a much shorter time) were more common during the early years. Figuring all that in, it is safe to assume that most of the mass on a rocky planet in the current universe went through about three star lifespans.

The second method involves the ratios of the radioactive elements in the earth's crust and mantle. Supernovae create certain isotopes of the heavier elements. Many of these are radioactive (i.e. uranium, radium, etc.) These slowly decay over time into more stable isotopes. Just as archaeologists use radio-carbon dating to date things that are hundreds or thousands of years old using the relative ratios of carbon isotopes, geologists can date the age of the heavier elements in the earth based on their ratios to one another, many of which have half-lives that are on the scale of millions and billions of years.  

Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/18/2007 02:44 PM
" I have always wondered why stars stop at iron though! "

The reason is actually fairly interesting.

Most nuclear fusion reactions produce energy; iron is the exception.  When a star starts fusing iron, it suddenly begins losing massive amounts of energy at its core.  As the pressure holding the outer layers out collapses, those outer layers accelerate inward to a significant fraction of c.  When they impact the core, the collision releases massive amounts of energy, fusing heavy elements and exploding the star.

That's my understanding, anyway.

There's a great Charles Stross book "Iron Sunrise," in which a weapon is devised that changes a star's core to iron, causing it to instantly collapse.

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/18/2007 09:01 PM
Pbelter,

I too would be happier if Bussard was doing an IPO. In fact I think he would already have the money if he did. I have to think his wife, who is the president of EMC^2, and who handles the business decisions, is at least partly responsible for decisions like this. It just seems like nobody wants the little guys like me to make any money! This seems counter to the American dream to me. I was watching Charlie Rose last night, they had an Indian guy on, Azim Premji, talking about how his company, Wipro, has been returning 30% compounded annually for that last five years. Is it fair to my kids to put money into a charity, or an education fund powered by such stocks? I can't justify screwing my kids out of an education.
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 05/18/2007 09:23 PM
Quote
I too would be happier if Bussard was doing an IPO. In fact I think he would already have the money if he did. I have to think his wife, who is the president of EMC^2, and who handles the business decisions, is at least partly responsible for decisions like this. It just seems like nobody wants the little guys like me to make any money!
As a recovering entrepreneur, I can tell you that any discussion of EMC2 doing an IPO is completely ridiculous.  IPOs are for big, established companies, and by the way they cost millions of dollars to prepare (especially with the new Sarbanes-Oxley regulations).  If he had the kind of money it takes to do an IPO, he'd be far better off using it to fund WB-7 and WB-8.

There are only a couple of ways that a small startup company can get equity financing: friends & family (within rather severe limits), angels, and venture capitalists.  There are a lot of potential angels for something like this: Branson, Allen, Spielberg, Buffett, Bigelow, etc.  I can only hope that Jim Benson is talking to these guys as well as he can, but we can't assume that will work out.  The NPO is a decent way to get grass-roots financial support while also looking for a saving angel.

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/18/2007 09:24 PM
High profits attract competition.

Don't ride it too long.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/19/2007 06:49 AM
Tergenev,

There is all kinds of evidence for rare and exotic states of matter.

On this newly found planet, ice is said to have many forms.

http://www.space.com/scienceastronomy/070516_hotice_planet.html

Here a new superfluid has been discovered.

http://physorg.com/news98645866.html

During the early cold fusion flap. Certain observations of what was thought to be helium-three species were said to be misinterpretations of triatomic molecules.

And it has long been theorized that metallic hydrogen exists in the cores of our giant planets.

And when some scientists have tried to create carbon wiskers with high voltage spark gaps in 80 atmosphere argon chambers they have gotten thin ribbon like filaments of silver colored "metallic carbon that acts like a synthetic metal" with unusual properties. Imagine what you could do with a nanometal from the carbon family.

I think we have just scratched the surface of what is possible with this fusion technology. The ability to transmute "metals" (metals meaning any element heavier than helium) into exotic forms may ultimately turn out to be its real value to the future of humanity.

Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/19/2007 07:20 PM
Tony,

Great link about the superfluid. Room temperature somiconducting could revolutionize the world and make Bussards reactor way less expensive to build and mantain.

Title: Re: Fusion with space related aspects thread
Post by: MKremer on 05/19/2007 08:04 PM
Quote
pbelter - 19/5/2007  2:20 PM

Room temperature somiconducting could revolutionize the world and make Bussards reactor way less expensive to build and mantain.
Something which has been (constantly) said since the late 60's and has yet to be practically proven (for any type of positive-energy fusion reactors that can sustain their output enough to fund, design, and engineer commercial test projects).

I wish Dr. Bussard all the best, but fusion reactor research has already been going on for more than 40 years, and one design after another has fallen by the wayside. All the millions (billions?) of taxpayer dollars spent has only shown us what won't work, rather than getting closer and closer to something (which has lots of positive results) that will.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/20/2007 03:54 AM
I'm looking for a chart of reaction rates (barns)  vs proton energy for p-B11.

Also fo D-D  and its reaction products.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/20/2007 07:39 AM
Something like this?

http://i38.photobucket.com/albums/e101/FogerRox/P-B11cycle.jpg
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/20/2007 11:31 AM
What size of power station would we be looking at for a 100 - 1000MW station compared to coal, gas, oil or fission?
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/20/2007 11:36 AM
Any suggestions as to the immediate effect on the economies of the Middle East, Russia etc should IEC prove to be successful for mains eletricity production.

Also, these people here

http://www.electronpowersystems.com/Applications.htm

are looking at using a 'plasma toroid that remains stable without magnetic confinement, by using background gas pressure for confinement instead. These plasma toroids are observed to remain stable for thousands of times longer than classical plasma toroids, which opens the way for new clean energy applications.'

One of the applications is a fusion powered car.

Oil is going to be needed for non energy uses but IIRC that is no more than 25% of current oil use. There will be a lot of legacy equipment that still uses oil or oil based products but things wouldn't look good for oil based economies.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/20/2007 02:12 PM
Most of the cost of a nuke plant is in the thermal conversion eqpt. The boilers and turbines and condensers.

Something like 80% of plant costs.

Direct conversion should cut that cost by at least 50%.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/20/2007 02:15 PM
Foger,

I'm looking for  barns (fusion cross section) vs particle energy.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/21/2007 01:48 AM
A couple of figure from my presentation at ISDC below.  The second plot combines cross-section with particle velocity to give sigma V.  The units are supposed to be cm^(3/5).  All you need for fusion rate per unit volume are the densities of the two species.

For a more complete set of data and a description of what is behind it, check out ...

http://fds.oup.com/www.oup.co.uk/pdf/0-19-856264-0.pdf

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/21/2007 02:04 AM
All ... be watching Askmar over the next few weeks ...

http://www.askmar.com/Fusion.html

I sent Mark Duncan at Askmar copies of four of Dr. Bussard's space papers.  Mark will do OCR scans on these and will re-draw any artwork that does not scan well (Mark did that Google talk summary that has some better figures).  He expects it may take a week or two to get the papers posted, but I'm sure you are all interested.

I'm probably not going to be on the forum much for the next eight days.  My company picked this time to send me on a road trip to test a new product.  Fortunately, I'm already fairly well prepared for ISDC.  I'll be heading to ISDC on Friday, talking on Sunday afternoon, 5-6 PM.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 03:21 AM
Thanks Tom!

If I understand the graphs correctly aren't they saying that for a minimum of power input the B11 should be injected at some low energy (say around a few 10s of KeV) and the protons need around 600KV for maximum probability of fusion?

The reason being that the reaction is dependent on relative particle velocities rather than just particle energy.

You could compromise by lowering the voltage some and accelerating both p and B11 with the same voltage but  the cost of the velocity (in energy terms is 11X as much for the B11 as it is for the p for equal velocities). If you use the same voltage for both the accelerators.

Thus the B11 costs you significantly more energy for a given velocity.

At 600 Kev for the proton  you are up to 7% of the output (not counting losses) just to get the p up to speed.

If all the energy was input to the B11 you are talking 77% of the output energy to get sufficient velocity.

Ideally you want to keep the energy input below 10% of the output.  Because there will be other losses. Like the conversion loss from alphas to an ouput voltage. The losses from that to the conversion to the accelerator grid voltage, cooling power, vacuum pumping power, the losses from conversion of 1.3 MV DC to AC, the losses to get the He out of the system while it operates, etc.

Example suppose you accelerated a p and a B11 through 100KV. The proton will have a velocity out of V. The Boron would have a velocity of .675V. However getting the Boron to that speed will cost you .5 MeV while the proton only costs .1 Mev.

Aproximatey you would need 400 KV for the accelerator (using the same voltage for both). Which means  roughly 2 Mev into the Boron or about 1/3 your  total energy output just to keep the reaction going.

Things are starting to get very complicated in the reaction chamber  if you need two accelerating voltages. Since we are depending on the Polywell for acceleration you can't have two different accelerator voltages. Which means inherently high losses.  OK fine. Except now you have excess energy in the p-B11 and that will result in a spread of resultant particle energies.  Which means lower collection efficiencies on the collector grids.

I'm sorry to say the more I look into this the more pessimistic I become.

D-D I can see. p-B11 is rough.

Even D-D is tough because of the neutron flux you are limited to Cu coils. Which means high magnet losses.

The HV supply is another tough one. A Crockoft-Walton voltage multiplier is in order.  say you need 30 MW @ 400KV. (around 75 Amps) To get acceptably low ripple the capacitors for that job are going to be huge. even if you use 70 KHz as your input frequency. In addition with 75 A @ 1 KV diodes you are going to need a lot of them. The junction capacitance is going to be high. Which ups your switching losses. Then you have to mount and cool those suckers.

Electrically this is tough job and we haven't even got any fusions yet.

Then you get into the fact that the higher you go in power the lower the frequency your semiconductors can handle  just from a junction capacitance stand point so 70 KHz may not be possible. You may be limited to around 1 to 5 KHz.

I sure hope there is a sweet spot in the reactor because the support electronics are going to be a brute force operation.


Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 04:06 AM
The part about excess energy was wrong. You just adjust the voltage so you get the required relative velocity.

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/21/2007 08:23 AM
PMN1,

If you watch the Google Video of the Bussard talk you will hear him say that most existing fossil fuel power plants could be retrofit with a something smaller than a standard shipping container. Since over 85% of the electricity would be gathered with direct conversion, most people don't understand that the remaining 15% of the energy coming out as heat can be fed into the old plant and turned into electricity as a form of "co-generation." This brings the total energy efficiency above 90%. This is phenominal, as most heat engines are less than 50% efficient.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 10:45 AM
Tony,

You have the numbers right except for one small problem. To get reasonable efficiency for the thermal side - 30 to 40% you have to generate 17X as much as the original plant was rated for directly from fusion.  Which means upgrading the electrical distribution from the plant by a huge factor.

i.e. if the current plan outputs  1 GWe then the fusion generators would need to run at about 17GWe output.

That is a lot of power!

I believe if you will look at the video again he was suggesting D-D fusion for retrofits. Which would make more sense since arout 50% of plant power would come out as electrical direct and the neutrons could be used to boil water. However, you would need a two loop system since the primary loop would be somewhat radioactive due to the neutron flux. With a two loop system you need a steam generator and pumps. Plus the primary loop needs to be pressurized to around 2,500 psi or 3,000 psi to allow for hotter temperatures than normal nuke plants since coal burners run hotter than nukes. You probably also need to do some kind of superheat to get plant efficiency up and to match the turbine design.

All do able. Easier said than done.
Title: Re: Fusion with space related aspects thread
Post by: Jim on 05/21/2007 10:58 AM
Where is the space applications talk?  Or is this just a nuke forum, because there is no other website that will host it?
Title: Re: Fusion with space related aspects thread
Post by: nacnud on 05/21/2007 11:20 AM
There are massive implications for space related applications from this work. As I'm sure you can see Jim :) . I think talk just about the basic technology is interesting and relevant enough alone to be allowed here.

This is advanced concepts after all, this is just as relevant to space flight power/propulsion as an indepth discussion of current AI research would be to Mars rover navigation.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 11:20 AM
I was looking at your slide again and I have found a fly in the direct conversion scheme if your data is accurate.

You have two alphas at 2.46 Mev and one at 3.76 Mev. For a total of 8.68 Mev.

If your collector grid runs at 1.23  MV  to collect the lower energy alphas you need to dump 1.30 MeV of energy when you collect the 3.76 Mev alpha. That is a 15% loss of energy right off the top and represents the cooling load on the collector grid (actually more like a surface so cooling will not be too tough).

Then because you are accelerating protons and B11 with the same virtual electrode  (the electron cloud)  most of the input accelerator power is wasted energizing the B11. That represents anotther 15% (roughly - I'm working on the numbers as we speak). So right off the bat you have a 30% hit on plant power. With the required auxiliaries (pumps, vacuum pumps etc) you are down around 60 or 65%  net output. Which is pretty good. Even if every thing else was perfect and you did thermal recovery your plant will at best be running at something like 70 to 75% net output.  With 15% of total output representing thermal load. It might make sense from a cost standpoint just to dump the 15% since thermal conversion represents about 80% of a nuke plant's cost. It still means that you have 1/4 the thermal load at the generating site re: a nuke or fossil fuel plant.

However 1.3 MeV alphas can do a LOT of sputtering to the walls of your reactor. Not too big a deal except that you will be inserting a lot of iron and other components of stainless steel into the reactor vessel. Not good.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 11:25 AM
Jim,

We are discussing the design of a terrestrial nuke plant prepratory to qualifying it for space.

The space discussion comes and goes.

Look up thread for that part of the discussion or ask questions. We are a friendly group.

Simon
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 12:55 PM
The ideal energy  for the p accelerated into the B11 is 550 Kev.

This gives an accelerating voltage where both p and B11 are accelerated of around 200 KV  (196KV).

With a total energy (both particles) of  1.177 Mev.

So my estimate of 15% of reaction energy was not far off. Actual is about 13.6%

You can see my work here:

http://iecfusiontech.blogspot.com/2007/05/operating-voltage-for-b11.html

*
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/21/2007 01:22 PM
Foger,

You have your Be marked incorrectly at:

http://i38.photobucket.com/albums/e101/FogerRox/P-B11cycle.jpg

It should be 8 Be

plus there are no photons.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/21/2007 03:25 PM
Given what this could mean for ships propulsion, I wonder if the USN would be willing to give up a Littoral Combat Ship especially since the program seems to have run into trouble.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/21/2007 05:47 PM
Jim,

Somewhere in the first few pages of this discussion, I put in some snippets of what this means for space propulsion.  I've condensed the main points of several of Dr. Bussard's papers into a PowerPoint talk for my talk at ISDC.  I uploaded a compressed version to the website last night, which appears to be available for viewing.  The talk will be this Sunday.

http://isdc2.xisp.net/~kmiller/isdc_archive/isdc.php?link=submissionSelectCurrent
(Scroll down to Tom Ligon and click on the PPT entry, if you have PowerPoint.)

The papers I took my information from have been sent to Askmar, who will scan and post them over the next couple of weeks, if all goes well.

Huge space implications.  If it works, the solar system is our backyard.  Space is what gets Dr. Bussard out of bed every morning, his main motivator.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/22/2007 01:35 PM
Tom,

Checked out the PPT, it opened right up with Open Office. Very nice. Is that a 3d rendering of WB8? Nice job by Tony & Skip, looks sharp. Have fun in Dallas.

Quote
M Simon - 21/5/2007  9:22 AM

Foger,

You have your Be marked incorrectly at:

http://i38.photobucket.com/albums/e101/FogerRox/P-B11cycle.jpg

It should be 8 Be

plus there are no photons.

One of askmar's mistakes, its from his pdf.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/22/2007 03:02 PM
China is pretty flush with money at the moment, what would br the reaction from the US administration if funding came from China.....
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/22/2007 03:52 PM
Wouldn't that get some attention!

I can see that Wiffle Ball (tm) Corporation might be annoyed by the use of the wiffleball term, as a general rule, as a trademark infringement.  But in this case, the association ought to be seen as positive.  I'm wondering if they might sponsor at least the WB7/8 research.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/22/2007 05:27 PM
Unfortunately, the Chinese are pretty mercenary.  I don't see them funding it as an open source project, and I don't see Bussard giving them ownership of the intellectual property.  We can always hope though.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/22/2007 05:56 PM
Short-term and medium-term, not much effect on oil producers.  I think we're looking at at least 20 years before commercial fusion is widespread, even assuming non-ITER plans work out.  Long-term, cheaply extracted oil's going to run out in a few decades anyway.  The major impact would probably be to Venezuela, the U.S., and Canada, where the more expensive tar sands and shale oil are concentrated.

I've seen a couple "stable toroid collision fusion" companies out there, which are interesting, but they still seem to be in the PowerPoint phase.  The "microfusion" applications they're talking about don't seem to make much sense (would you drive a car with neutron flux?) unless they can do p-11B, which is going to be quite a challenge.  We'll see if they get funded.


Quote
PMN1 - 20/5/2007  6:36 AM

Any suggestions as to the immediate effect on the economies of the Middle East, Russia etc should IEC prove to be successful for mains eletricity production.

Also, these people here

http://www.electronpowersystems.com/Applications.htm

are looking at using a 'plasma toroid that remains stable without magnetic confinement, by using background gas pressure for confinement instead. These plasma toroids are observed to remain stable for thousands of times longer than classical plasma toroids, which opens the way for new clean energy applications.'

One of the applications is a fusion powered car.

Oil is going to be needed for non energy uses but IIRC that is no more than 25% of current oil use. There will be a lot of legacy equipment that still uses oil or oil based products but things wouldn't look good for oil based economies.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/22/2007 06:28 PM
Obviously they have not thought this through.

The shielding required would put the car in the 100 ton range or higher.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/22/2007 06:50 PM
Tom,

Your presentation stands out compared to the others posted ont he site.
The only thing I would change id the sudden transition between slide 12 and 13. The schematics on 13 may be difficult to grasp by audience not familiar with the concept. It might be worth to put additional slide in between with a picture of a single maget and then drawing of how it appears on the shcematics. Something like FogerRox did on his video.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/22/2007 06:58 PM
Trade Mark infringement is an iffy propositioin in this case.

Two completely different fields.

It is not an open and shut case.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/22/2007 07:35 PM
Pbelter,

Heck, if I can get it to run, I'll probably use the video!
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/23/2007 12:09 PM
Quote
TallDave - 22/5/2007  12:27 PM

Unfortunately, the Chinese are pretty mercenary.  I don't see them funding it as an open source project, and I don't see Bussard giving them ownership of the intellectual property.  We can always hope though.

Is enough known outside of Bussard's group for it to be possible for China to prove the concept ?

It has a lot of money, a massive demand for energy and doesn't really have to worry about vested intrests within the country - if anyone objects, just send in the PLA.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/23/2007 12:19 PM
PMN1 asks:


Is enough known outside of Bussard's group for it to be possible for China to prove the concept?

I would think that the papers and talks given by Dr. Bussard would be sufficient to replicate the experiments.

With sufficient experimental data you can do reactor design.

It might take them 3 or 4 years to get the required results. Esp. if they had two or three teams in cooperation/competition.

============

Right now I'm leaning towards pulsed operation as the most feasible way to extract He from the chamber.

You run the reaction until you get He poisoning and then let the pumps pump it out.  Then inject a new batch of H - B11 and start it up again.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/23/2007 05:17 PM
I don't know that He would build up that fast, but the machines so far do tend to load up with hydrogen (evolved from the walls).  If that can't be controlled by agressive pumping, it triggers a Paschen discharge.  Periodically turning off the machine would allow that to be cleared.

Same basic idea.  If it needs intermittent operation, we'll run more than one.
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/23/2007 05:59 PM
Why am I having vision's of a Saturn V sized pump room hooked up to an apollo capsul sized fusion chamber?

It does bring up a good question on pumping, Cryo pump's are useless for H2 and He. How effective are Turbo Molecular pumps for H2 and He?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/23/2007 07:09 PM
It is unlikely to be that bad.  Turbopumps seem to work pretty well.  The chamber in which WB6 was tested had plenty of pump for getting it down to low pressure with no test running, but may have been under-pumped for high gas loads generated in the test.  It had 6 1100 liter per second turbos, each mounted on about an 8" diameter tube, in a chamber 12 ft long and 6 ft diameter.  The open port area was pretty small compared to the wall area, so a molecule would rattle around for a while before finding a hole.  More port area and pump capacity probably would have helped, but we already had about $75k of turbopumps on the beast.  A shorter chamber would also have helped.

A working p-B11 reactor may wind up with the pump ports located in the shadow of the magrid, so they do not compete with the power conversion operation.  

The other thing that will help is longer run times.  These things won't keep generating trash gas indefinitely.  The metal will eventually stop evolving hydrogen every time you turn it on.  Real power reactors should not be as bad as research machines that are run a few pulses before being opened up and worked on.

I'm not worried about vacuum availability for space applications.  Valves are cheap.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/23/2007 10:15 PM
Tom says,

I don't know that He would build up that fast, but the machines so far do tend to load up with hydrogen (evolved from the walls). If that can't be controlled by agressive pumping, it triggers a Paschen discharge. Periodically turning off the machine would allow that to be cleared.

I have heard that some working on p-B11 coat the walls of their machine with B11 to reduce the problem of wall sputtering and outgassing  and also provide a source of B11.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/23/2007 11:06 PM
Tom!

Great PPT presentation man! I wish I had done a few space ships for you!
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/23/2007 11:24 PM
Well, the dodec art is certainly gorgeous.  The lunar lander is a Bussard Original (right out of a paper!).  

I never did get around to sending you those spacecraft papers.  I sent them to Askmar.  Mr. Duncan is going to do some scanning and try to get them posted.  In the process, he'll probably make new art like he did for the Google talk summary.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/24/2007 12:22 AM
Hi Tom,

Is your presentation at ISDC going to be videotaped? If so can you post it on Google Video?
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/24/2007 12:26 AM
Just had a thought.  One of the issues with energy recovery from the 3 Helium ions is that one has a much higher energy level than the other two.

This causes, wasted energy and sputtering of the reactor walls.

How about this solution.

Make the outer wall nonspherical. and charge it up to the point where only the high energy He ion can reach it.

The two lower energy ions from each reaction would bounce off of the outer wall.  If that wall has the right shape, it will act as a mirror to focus the lower energy ions to a small area.  That area would be charged to only the lower energy level of the low energy ions.

This way, almost all of the high energy ions get to deposit almost all of their energy.

Most of the lower energy ions also get to deposit most of their energy.

1) This would increase overall efficiency.
2) Reduce sputtering and damage to the outer wall.
3) Most of the outer wall damage would be confined to the small area at a lower voltage.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 01:09 AM
The lower energy ions won't have the kinetic energy to reach the walls.  We hope it will be possible to put grids somewhat inside the outer walls at a little lower voltage.  If put in the shadow of the magrid, the high energy ones should ignore the grids, but the low energy ions will take what they can get and turn to the grids.

The beauty of the system is the energy of the particles hitting the walls should be low.  Only the magrid inner surface gets cooked.

Pbelter ... I don't know if they videotape it.  My camera is analog and I'm not sure it is worth taking.  

My company is trying to kill me ... I'm still at work at 9:13 PM, 70 miles from home, at a lab we're hiring, and we're not done yet.  And I have to be back tomorrow morning, work late again, get on a plane to Dallas Friday AM.  Good thing the talk is not Friday.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/24/2007 01:45 AM
I saw your powerpoint slideshow, pretty good!  However I didn't understand slide #32 - "Tokamak vs. QED Radiators".  Is that big square a top view of radiator fins?  And what is the little "nub" on the right side of it, is that the reactor?  If so, why would the tokamak look the same as the pB11 reactors?  Isometric views might be better than orthographic just because they are more intuitive at first glance.

The cost estimates for the space power slides seem a little arrogant.  After all the tech isn't proven yet.  And others have made huge efforts and not come close.  They might dismiss Bussard's technology on that basis, thinking you don't have enough experience to make such claims.  You may want to cite alot of references besides Bussard's papers, maybe some from JPL and NASA as well, breaking down some of those costs into components that are proven and clearly distinguishing them from the cost component for the unproven fusion tech, which would be estimated based on a "net-power-scale" reactor.  That would be alot more convincing.

Didn't see any other problems.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/24/2007 01:53 AM
Tom,

If you are not a member of the  IEC Fusion Yahoo group you should join.

http://tech.groups.yahoo.com/group/IEC_Fusion/

Indrek is doing some wonderful simulations of electron paths in the reaction space. With visuals.

If you are not a joiner you can just lurk and take a look at Indrek's stuff.

His latest offerings are very interesting.

I'm sure Indrek would appriciate an attaboy from you.

Simon
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 02:02 AM
I think I was the second member! I'm just so tied up right now on this, fusor.net, ISDC, etc, I have not had time to check in.

Semper,

I think basically the same thing every time I look at that figure.  Yes, all the reactors look like tokamaks.  But the real comparison is the radiator area.  The little models are too scrawny to make out, too.  They're from one of Bussard's papers ... not my art.

The cost estimates are absurdly low ... and yet if you look at his arguments in the source papers they make sense.   They're not numbers you could take to the Congressional Budget Office.  Bussard describes these papers as "just for fun", and they are all the Navy would let him publish during the embargo.  But they do illustrate what happens if performance gets the payload fraction up, travel times down, and do that for every phase of the operation.

He puts SSTO at less per kg than they used to charge to fly to Europe on the Concorde.  To Mars, a price we would kill for to LEO today.  Gee, I hope he is right.  But you are right, it sounds absurd.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/24/2007 04:53 AM
We hear from you so infrequently I forgot. My apologies.

In any case have you seen the latest?

Might be useful for your slide show,
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/24/2007 05:41 AM
Good luck at ISDC.  I've always wanted to go to conferences and stuff like that, meet famous people.  Never had enough time, or it cost $thousands to attend, or they were thousands of miles away on the other side of the Atlantic.  I'm interested, but not that interested.  I can always read about it.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 01:50 PM
MSimon,

I have not been lurking much, usually just when you post a link.  Frankly, I've forgotten the password and this laptop has never been used for it so it doesn't remember either.  I'm also on a cycling group on Yahoo, and the desktop at home is where I usually log it.

Semper,

Yeah, a thousand or so, anyway.  I did an ISDC years ago, but it was in DC and just a short drive away, so I could afford it.

I wouldn't ordinarily even consider it, but this is my chance to pay Dr. Bussard back for giving me such a great opportunity.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/24/2007 03:09 PM
Put up another Polywell post at Dean's World.

http://www.deanesmay.com/posts/1179866647.shtml

Not too much new here, but a lot of links.

I'll also try to put up something next week after Tom's presentation.  The PowerPoint slides look great (the details on the WB series are especially helpful), hopefully they generate some more interest in Polywell.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 05:13 PM
Who here can log on to fusor.net?

I'm stuck here inside the Baltimore Beltway running tests at MET Labs, and I don't have my username/password for fusor.net with me.  Outside, in a large dumpster used for metal recycling, is a huge vacuum bell-jar, stainless steel, rigged for double o-rings, a large window on top.  Must be 4 ft diameter and over 4 ft high.

The thing is probably big enough to operate a WB3-sized magrid at fusion conditions.

One of those guys might want to make MET an offer before it goes off to be melted down.  There should be an equipment exchange forum for posting it.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 05/24/2007 09:00 PM
Tom,

your last post here has been copied to a new thread at fusor.net
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 09:22 PM
Thanks!  With my schedule tonight it is not clear I would have been able to post at home.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 09:54 PM
So I'm browsing the Science section on Yahoo News, and come across a headline for the ISDC opening.  I just had to look.  And there I encounter two people who have e-mailed me in the last couple of weeks, both of whom I will probably meet.  It is not an every day experience for me to meet with a newsmaker, much less two.

http://news.yahoo.com/s/space/20070524/sc_space/nationalspacesocietyconferencekicksoffindallas;_ylt=AsRLNdkp6kmH2Z1EpciqL9bMWM0F

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/24/2007 10:51 PM
BarryKirk,

One of the posters at fusor.net complained about the size vacuum equipment it would take to run it.  I just got a closer look, and the bloody thing has a diffusion pump on it as tall as I am!

It is marked as environmental equipment, so it may actually be a small space chamber.  It was evidently designed to be used with the "jar" horizontal and a door attached ... maybe that's in the dumpster too, or a thick, flat plate could be used.

This thing is just begging to be the home of the first amateur-built magrid Polywell.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/24/2007 11:55 PM
Why is it in a dumpster?  Is there something wrong with it?  Does it have fatigue cracking or something?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/25/2007 12:49 AM
Tom,

Please send Instapundit a bit on your up coming ISDC fusion talk.

He is looking for fusion stuff. Fusion and space (another interest of his) should knock his socks off.

If you can't post to him put it up here and I will forward it.

Simon
Title: Re: Fusion with space related aspects thread
Post by: kevin-rf on 05/25/2007 01:01 AM
Depends on what it was used for. If it was for research, it might have been relaced by the profs. latest greatest grant that bought him a new chamber. Though my experience with grant writing profs. is they are pack rats (so I doubt it).

It might have been exposed to  something (not necessarly toxic) that makes it unsuitable for future use. A clue here may be the diffusion pump which indicates very high vacuum. If it used a !#%$$^& oil roughing pump that failed the walls might have gotten a nice oil coating and I can tell you first hand what a pain it is to clean that mess out. Remember a nice palm print inside the chamber will keep you from getting much below 10-8 torr.

Or it could be for an industrial process that is no longer needed and might just be fine. I recently found out we tossed a similar sized bell jar when we switched buildings (but kept the $%^? oil pumps!).

If it was used for an industrial process chances are it was a coating process and has an electron beam gun inside. Something that would be very useful.

What kinda building is it outside?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/25/2007 02:43 AM
METLabs is a compliance testing company, EMI, safety, MIL-STD, etc.  They have a number of environmental chambers of various types, including at least one altitude/temperature chamber.  This was probably a small space simulation chamber.
The flange on the viewport is a little rusty, and the door is not on it (a thick flat plate would suffice, since the seals are in the flange of the bell jar).

http://metlabs.com/

It has a huge diffusion pump mounted on one side.  Possibly it has a burned out heater or something, but most likely they just decided that it would be better to retire it and use a chamber with a turbomolecular pump.  As an environmental test chamber, it is unlikely to have any harmful contamination.  I asked, and the fellow I was with said "Hell, we throw out all kinds of neat stuff."

John Carmack is looking for a fusor chamber ... I should see him this weekend and will let him know about it.
Title: Re: Fusion with space related aspects thread
Post by: TallDave on 05/25/2007 06:42 PM
Actually, it was an email with Tom's presentation that sparked Glenn's question.  I would guess it was the space stuff that piqued his interest.

I'm not sure he's going to link anything here; all this is still pretty esoteric and baffling to most people, and he has a legion of critics who would love to pounce on anything that looked like an endorsement of a wacky idea.  Not sure he has the time or inclination to really delve into it to discover that's not the case here.

But it's great that Tom is giving the presentation.  Hopefully that keeps the ball rolling.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/25/2007 06:50 PM
I have read Glenns stuff avidly for what?  8 or 9 years. (I may be off on that - when did he start?  Before 2000 I'm sure.) I look at his site a few times a day - at least. Mosly because I'm well attuned to his politics.

For a lawyer he is very technologically savy. I have been surpised at times by how much.

I've been pitching  Bussard fusion articles at him since I started writing them. He likes my political stuff (I get a link every month or two). The science stuff not so much.

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/25/2007 07:12 PM
This is probably not new, but I found this animated gif of IO erupting.



Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/26/2007 01:13 AM
Instapundit is at ISDC!!!!!!

http://instapundit.com/archives2/005645.php

http://instapundit.com/archives2/005644.php

Updates:

http://www.instapundit.com/
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/27/2007 12:47 AM
Have not run into them yet, that I know of, but the fellow who invited Dr. Bussard set up a really nice display with some materials I sent him, and it is getting lots of attention.  I met John C. this morning, serveral other space venture capitalists, and I'm in a very optimistic mood.

We shall see.

I'll be looking for Instapundit.  Possibly we met already and I just didn't know who it is.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/27/2007 12:53 AM
I have a post up at my blog on the latest in fusion news.

One bit:

Monkhorst got a $40 million VC commitment with a $5 million down payment.

I also link to Tom's  Power Point presentation.

http://powerandcontrol.blogspot.com/2007/05/latest-fusion-news.html

Tom, Instapundit is one of the biggest bloggers around and a former wheel in the space community. He is also a lawyer. He should be showing up at your talk. He seems very interested.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/27/2007 02:28 AM
Here is a photo of Glenn/Instapundit.

He is the young guy in the photo.

http://instapundit.com/archives2/005655.php
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/27/2007 07:19 AM
We managed to meet briefly.  He mostly wanted links, and the Askmar site will probably give him what he needs.  He'll be leaving tomorrow morning before my talk.

He was talking to an MSNBC reporter, who seemed more interested.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/27/2007 12:07 PM
Tom,

When you get back I'd like to discuss reactor dynamics. I know a fair amount of control theory and I'd like to work out in a preliminary way some of the control dynamics.

i.e what are the min/max conditions for fusion, the rate reactants must enter, delays etc.

If controls can be done on millisecond time scales we are home free. If we have to get controls that react in microseconds it gets tough, in fact at those kinds of speeds it is not only the reaction responses that limit you but also the speed of light. Not to mention speed of measurements.

One of the things that makes control of fission possible is the delayed neutrons. Under ordinary control regimes they give power doubling times with small changes in reactivity on the order of 20 seconds.  Is there any similar dynamic in a Bussard machine? Or is it just inject the reactants and hope for the best? I was rewatching the Google video and Dr. B. was talking of responses to injected fuels on the order of microseconds. Now that I understand more it has bothered me.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/27/2007 06:02 PM
If the idea was proved today, how quickly could an IEC fusion power station be brought on line and how many would current component manufacturing capability allow to be under construction at any one time?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/27/2007 06:28 PM
I think the net power demo reactor was set at 5 years.  How long after that for a workable powerplant would depend on how intense the effort was to support the additional engineering, and if DD or p-B11 was chosen.

I would think it would be a bloody miracle if you could go from the net power demo to a workable powerplant in under two years.  For working steam plants retrofit to existing powerplants, I would think you could do it in under 5 years, assuming the economics are sufficiently compelling to warrant the intense work (and this should be the case if the demo can operate at 100 MW sustained).  

p-B11 might take a little longer.

Early plants would probably not be multi gigawatt per reactor, but there is no need to be greedy.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/27/2007 06:37 PM
http://powerandcontrol.blogspot.com/2007/03/mr-fusion.html

How much money do you have?

If you have unlimited funds to buy you  a place at the head of industial ques about 3 years to a reactor that could deliver power to the grid.

This assumes you handle it like the Manhattan Project where they built a number of reactors to get a handle on scaling problems as they designed their multi-megawatt Pu producing units.

The reason it can be so fast (it took about 10 years to go from the plans of the U Chicago reactor to the first submarine reactor) is that a lot of equipment was designed from scratch.

Most of the stuff we will need - vacuum pumps, HV supplies for test, instruments etc. is off the shelf.

Let me add that no factory is required for fuel enrichment. I have a book from 1953 on reactor design that is very interesting historically and helps a lot with general concepts and especially reactor shielding. Some of the early test reactors had cores that were cubes 20 inches on a side including Uranium reflectors. The actual power producing core was about 6 or 7 inches across (30Kw thermal output).

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/28/2007 04:29 AM
Check out the new posts at Askmar!  Mark Duncan has a couple of Dr. Bussard's space papers posted, and they look better than the originals!

http://www.askmar.com/Fusion.html
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/28/2007 11:37 AM
Quote
M Simon - 23/5/2007  7:19 AM

PMN1 asks:


Is enough known outside of Bussard's group for it to be possible for China to prove the concept?

I would think that the papers and talks given by Dr. Bussard would be sufficient to replicate the experiments.

With sufficient experimental data you can do reactor design.

It might take them 3 or 4 years to get the required results. Esp. if they had two or three teams in cooperation/competition.


So what we need is to persuade the Chinese to fund the research even though they wont get any additional benefit from it - tricky...

 :)
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 11:51 AM
PMN1,

The benefit they get is the ability to ramp up power production more quickly without the the need for a lot of long distance transmission. If plants are cheap enough you get the redundancy that long distance transmissions supply by adding plants locally.

China is ramping up ITER style fusion spending.

Transmission lines make sense when the cost of capital for plants is high.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/28/2007 03:12 PM
Quote
M Simon - 22/5/2007  1:28 PM

Obviously they have not thought this through.

The shielding required would put the car in the 100 ton range or higher.

What kind of shielding would be needed for their fusion method and how much would an IEC design need?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 04:17 PM
PMN1,

I'd have to go back and look at it.

But here is a bit off the top of my head - D-D or D-T fusion is going to make neutrons. Some of those neutrons will make capture gamas. Gama ray shielding can be done one of two ways. Distance or mass. Basically - with a few exceptions that are not relevant - gama shielding is a mass effect. It takes a certain amount of mass to do the job. What the mass is made of is not a significant factor except for cost and volume.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/28/2007 05:09 PM
http://video.google.com/videoplay?docid=7275796949506354740&q=fusion+Inertial&hl=en

These people claim to produce net power...... Yup, LOL
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/28/2007 06:01 PM
Tom,

Did anyone film your talk? I hope you chop it up into seven minute segments and put it on You Tube! Did you meet David Stuart? He is from Seattle and films things.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/28/2007 07:35 PM
You tube is the most popular, though the 10 minutes or 100mb limitation is a drag. Over here one can up load the entire talk at amuch higher quality:

http://blip.tv/

And one can down load ones own copy in wmv format, unlike You tube.

http://fogerrox.blip.tv/file/239051/
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 08:17 PM
If you haven't visited

http://tech.groups.yahoo.com/group/IEC_Fusion/

Lately come over and have a look.  harakas42/indrek has posted some of his simulations which now include a charged grid.


Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/28/2007 08:48 PM
I added music

http://www.youtube.com/watch?v=jmp1cg3-WDY
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/28/2007 09:16 PM
Geez, Doc is talking about a trip to the solar gravitational lens point, IIRC 550AU.

http://www.askmar.com/Fusion_files/The%20QED%20Engine.pdf
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 09:27 PM
Foger,

Thanks for the music!

I have posted it at my usual haunts.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/28/2007 10:25 PM
Toni,

They did do a video, with nice equipment, but it was late in the day and they did not have it copied by last night.  Nobody was around this morning.  They normally sell DVD copies for $20 each, 7 for $100.  This no doubt means they claim a copyright, but maybe some deal can be struck to post parts of it.

I get one copy free.  I was sort of figuring I'd buy a few to spread around.  Certainly one for RWB, one for you and Skip for the dodec drawing, Roger certainly rates one for the animation, probably MSimon for all his work, and for the guy who invited Dr. Bussard, then got us display space for free, and finally set up the display for me when it needed to go up the day before I could get there (and set up the best display at the show).

The dodec rendering and the animation were terrific additions.  I had all sorts of links posted for Askmar, here, fusor.net, the Yahoo group, etc.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/28/2007 10:40 PM
Hi Tom,

How was your presentation received? Any potential investors on the horizon?
What is your overall impression from ISDC?

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/28/2007 11:03 PM
All,

As you go over Dr. Bussard's papers at Askmar, remember that these are new OCR scans of the text.  There are occasional mis-read characters, so treat this as a beta release.  If you notice any, post me by the private mailbox here or my home e-mail, which would be my user name here with no spaces and happens to be at verizon dot net.  (Die, spambots, die!)  I'm marking up the Cis-Oort paper now.

The figures are so much better than the originals there is no comparison.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/28/2007 11:13 PM
Pbelter,

This is the first time I did not pack a room, but I've never had an auditorium this large, either.  Probably about three dozen people came to the presentation, and got a standing ovation, and got mobbed with questions afterwards.  I also talked to a lot of people at the display that Mitchell James (a local NSS mover/shaker) arranged and set up for me.

On the other hand, Robert Zubrin didn't pack a room, either.  This was not a science fiction worldcon with ten thousand fans in costume.  It also had 5 talks going on simultaneously at any given time, and I probably had one of the larger turnouts.

More importantly, I got some face to face time with several people who had come for the space finance symposium held Thursday, leaving me in a very optimistic mood.  Remember, I'm only a cheerleader, not a dealmaker, but I'd say the right type of people were interested, and very favorably impressed.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/28/2007 11:28 PM
Quote
Tom Ligon - 28/5/2007  7:13 PM

 This was not a science fiction worldcon with ten thousand fans in costume.

Whew, thank heaven's.

I went to a gaming Con once, representing the store I worked for, I was introduced to LARPers.. OMG...
Title: Re: Fusion with space related aspects thread
Post by: braddock on 05/28/2007 11:36 PM
Quote
Tom Ligon - 28/5/2007  6:25 PM
They did do a video, with nice equipment, but it was late in the day and they did not have it copied by last night.  Nobody was around this morning.  They normally sell DVD copies for $20 each, 7 for $100.

Why not just record your talk now while it is fresh in your head, and mail the recording to RogerFox or someone with the final powerpoints and have him cut a video.

It will be seen by FAR more than three dozen people that way...
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 11:37 PM
With $40 mil promised and $5 mil cut loose for Monkton the rush should be on.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/28/2007 11:44 PM
Tom,

If you like the video give me a url for the guys selling it and I will see if I can push a few copies out the door.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 02:02 AM
Control,

Control of the Bussard reactor is dependent on the reaction rate and the fuel supply in the chamber and how wide the operational parameters (gas dentsity, etc.) can vary and  maintain output. Plus How well you can control the inputs.

First how long from fuel injection to fuel burn.

Second - maximum density of operation.

Third burn rate.

My guess is that the easiest way to control the reactor is to control the accelerator voltage provided you can keep the ripple down.

BTW Tom - you will need to dump power fron the Magnetic Grid once the machine starts operating from the He++ that hits the grid.

It will not be very efficient and most of the energy will have to be drawn off as heat. But still you will have to load it. That might be a good place to get some net power from an experimental 100 MW reactor. Back of the envelope: 20 MW of alphas's hitting the grid. 2.83 Mev average voltage. Figure you have to dump 7% of that electrically. That is .4 Mw. At a pretty easy voltage relatively.

Of course if you want to be cheap you can use resistors.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 03:16 AM
When you guys talk about 100 MW reactor, are you stating the amount of net power (over and above that needed to run the reactor) or are you stating the total energy of the fusion reactons?

Someone ought to make a distinction here, because the results drawn from that can be quite different.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 04:08 AM
Sempi - I refer to Fusion power.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/29/2007 04:13 AM
I think it was the google talk, that Dr. Bussard was talking about a reactor that powers 100mw generation of electricity. IIRC a nuke generates about 1000 to 1200 mw. Is that ballpark M. Simon?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 10:35 AM
A typical large fission plant produces about 1,000 MWe and about 3,000 MWth. Which is how the nuke guys differentiate.

Roughly, you have to dump 2 J of thermal  energy for every J of electrical energy. Carnot.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 11:43 AM
Does any one have links to the Elmore Tuck Watson work?

I'm ready to write up a bit on well formation and I'd like to go to original sources.

I am having trouble finding the ETW patents on line as well.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/29/2007 03:01 PM
I found an interesting presentation from 2002 about status of IEC research in the US.
http://fti.neep.wisc.edu/iecworkshop/PDF/OVERVIEW/overview_Kulcinski_US.pdf
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 03:30 PM
Yes I found that too!

I put a link to that in the sidebar of Power and Control
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 03:41 PM
Lubos Motl, a physicist at Harvard, has put up Roger Fox's video.

http://motls.blogspot.com/2007/05/bussards-iec-fusion-for-dummies-video.html

Check out the rest of his site - he is big in string theory.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/29/2007 04:51 PM
MSimon -- It is rare to find 1959 papers on the internet.  I have a hardcopy of the ETW paper.  E-mail me your mailing address at my home e-mail.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 05:54 PM
You guys realize that a 100 MW reactor based on fusion energy alone might not be a net power reactor?

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 06:34 PM
I just put a bit up that should give us some ammunition.

Proof the Polywell forms.

http://powerandcontrol.blogspot.com/2007/05/polywell-making-well.html
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 06:38 PM
Semper,

I have done back of the envelope calculations. In my worst nightmare I can't imagine an output less than 1/3 the fusion energy. Very likely is 50% and 75% is not impossible.

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 07:25 PM
Modern heat engines, for example car engines, don't do better than 20% conversion of fuel energy to mechanical work.

From 100 MW of fusion energy:
-20 MW might be blocked by the magnets, requiring a pumped heat exchanger to keep cool.
-p1 MW might be lost to Paschen discharges.
-p2 MW might be lost as heat in the electrical power conversion grid and also require cooling.
-(20 + p1 + p2) MW electricity would be required to drive the heat exchanger pumps.
-p3 MW electricity would be required to drive the magnetic fields and electron guns.
-p4 MW electricty would be required to electrolyze water & compress hydrogen, and also purify boron-11 as fuel.
_____________________________________________
Net power = 100 - 20 - p1- p2 - (20 + p1+ p2) - p3 - p4
_____________________________________________

I think that's a pretty conservative formula, especially considering I only have a conceptual understanding of the inner workings of a fusion reactor.  Notice that alot of energy in the form of electricity is required to run the reactor and the cooling pumps.  This electricity would only be available if it were generated in the first place, i.e. from a net power producing process.  Otherwise it would have to come from another source, and this would not be a net power reactor (left side of formula would be a negative number).  I imagine the first 100 MW reactor would have an outside source of power for all systems, independent of the power produced by the reactor.  If it managed to produce net electricity it would have to "sell it back to the grid".

Eventually we'll have to decide if we're producing enough power from fusion to justify burning through so much boron-11 resources, or pumping out so much Helium emissions, and such.  Even if it is feasible and net power producing, does it sell enough electricity to amortize the costs of the equipment over the expected operational lifespan?  These are engineering questions that haven't been addressed.  I think regardless of whether the power scales with the 7th power of the radius, these economic aspects might be better addressed with incremental size reactors.  That way improvements in the economics of the system can be made.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 07:36 PM
If you can reject the heat with a  large delta T the cooling pumps get smaller.

Say from 150 C  to 250 C or so to 30 C cooling water.

The first plant does not need to work in a desert.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/29/2007 07:37 PM
Semper,

Power gain scales as (B^4)*R.  When power gain is over 1, you are into net power.  That's seperate from the power output scaling (B^4)(R^3).  

I believe if you check Dr. Bussard's report and talk, he says he expects a hundred MW NET POWER, that is over unity.  The amount of net power produced is calculated by a program called PBAL, if my memory serves correctly.  I have not poked at it's insides, but PBAL basically does what you say ... calculates power out and subtracts power needed to drive the machine.  It also makes a big difference if copper or superconducting magnets are used.

All the calculations in the world, don't prove anything, of course.  You have to run it and actually measure what it takes to drive it versus what it produces.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 07:39 PM
Semper,

We have a 100,000 year supply of B11 if we powered all the electrical grids in the world with B Reactors.

Helium produced in a year by all that poweering? A few hundred tons at most.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 07:44 PM
Semper,

Plant costs. Most of a nuke plant's cost is in the thermal conversion eqpt. 80%.

Then you have fuel costs - enriched hydrogen? Not very much. Pure boron? Not very much.

So most of your cost is capital eqpt. The rest is operations and maintenance.

Once you go into series production costs come down drastically.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 07:46 PM
Tom,

Can you still get net Power with Cu? About what %?
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 07:47 PM
Ok.  That's a different relationship then.  But I can use a similar formula.

From "a" MW of total fusion energy:
-0.2*a MW might be blocked by the magnets, requiring a pumped heat exchanger to keep cool.
-p1 MW might be lost to Paschen discharges.
-p2 MW might be lost as heat in the electrical power conversion grid and also require cooling.
-(0.2*a + p1 + p2) MW electricity would be required to drive the heat exchanger pumps.
-p3 MW electricity would be required to drive the magnetic fields and electron guns.
-p4 MW electricity would be required to electrolyze water & compress hydrogen, and also purify boron-11 as fuel.
_____________________________________________
Power Output = a - 0.2*a - p1- p2 - (0.2*a + p1+ p2) - p3 - p4
_____________________________________________

If p1...p4 are known then required total fusion energy "a" can be calculated.  And from that the radius of the reactor needed for a desired amount of power output, e.g. 100 MW.  But I think it's a bit of a shot in the dark to say that "r" radius will give 100 MW power output.  In fact if unity cannot be achieved, say because losses are too high, then the left side of the equation will always be a negative number.

Some people might be irritated that p4 is included in the formula.  But as with other alternative energy sources, e.g. ethanol, there is quite a bit of dispute over whether a postive net balance of energy is achieved.  So I included that term in the formula.  Environmentalists would probably internalize many more costs as well.  This is why economics is ultimately the determining factor over whether this technology might be implemented.  Money is in many ways equivalent to energy.  If there isn't profit to be made, then it can be argued that there is a negative energy balance, perhaps because the entrepreneur failed to internalize all the costs associated with the technology.  He might make a profit in the short run, but those costs catch up with us.
Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 05/29/2007 07:59 PM
Quote
M Simon - 28/5/2007  11:17 AM

PMN1,

I'd have to go back and look at it.

But here is a bit off the top of my head - D-D or D-T fusion is going to make neutrons. Some of those neutrons will make capture gamas. Gama ray shielding can be done one of two ways. Distance or mass. Basically - with a few exceptions that are not relevant - gama shielding is a mass effect. It takes a certain amount of mass to do the job. What the mass is made of is not a significant factor except for cost and volume.

They appear to be using the same hydrogen-Boron fuel as IEC - at least for their 6kw power supply system.

http://peswiki.com/index.php/Directory:Electron_Power_Systems_Ltd
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/29/2007 08:00 PM
Tom,

Regarding a DVD of your talk. I'd rather see it on You-Tube! I don't know how you feel, but I'd say put it out there on the net and let the world see it!

My big point is that I think there is a materials processing revolution waiting out there after we figure out practical economic fusion.

I just read that the core of a white dwarf star is a huge diamond twenty miles in diameter!

http://www.space.com/scienceastronomy/top10_star_mysteries-10.html

Anthony Zuppero says the near earth crossing asteroids are probably one third dirt, one third water ice, and one third tar.

http://www.neofuel.com/2005.01.19_space05_09211248Zupp/index.html

That sounds like a pretty rough estimate. If the folks at JPL want to do some real work they should be gearing up to go catalog the material in the asteroid belt beyond mars.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 08:11 PM
Tom Says:

All the calculations in the world, don't prove anything, of course. You have to run it and actually measure what it takes to drive it versus what it produces.

Which is why I'd like to sneak up on the goal if possible.

Dr. B. says the reactor should be operational over a 5:1 fuel density range.

Now if I knew the rate of burn vs fuel inventory it ought to be possible to to work out the minimum control response time.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 08:23 PM
Internalizing as many costs as possible in the short run will make this technology appear more environmentally sound.  If you announce those efforts up front they'll lift you up on their shoulders and carry you out on the street with cheering and bullhorns.  The left-wing media will put you on the front page of every newspaper, and do it regularly.  Call it a publicity tactic.  Regular exposure is in fact how politicians get noticed.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 08:39 PM
For lack of a student-level paper on the subject, I never understood the formulas given.  For example:

"Power gain scales as (B^4)*R."

"the power output scaling (B^4)(R^3)."


What are the actual equations?  Are there proportionality constants or functions?  What units (meters, kilograms, gauss, etc.) are used?  Is power gain the same as a fractional power gain, for example would a power gain of 1.02 be interpreted as 2 percent net power?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 08:45 PM
Semper,

So far the result is mostly indifference.

Dr. B's Youtube presentation is currently getting 300 visitors a day.

Not bad, but we need to get 10,000 people a day to see this stuff.

Roger Fox's simplification (which is not entirely correct because it does not show beam formation) is definitly a very good move in the right direction.

It is close enough for the general public.

I know I'm asking a lot now that I got music - which I have already gotten a positive comment on - but I'd like a voice over reading the text.

Turn it into a commercial.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 08:48 PM
B is just the magnetic field. Amps * turns.

R is the radius of the reaction volume.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 08:51 PM
What are the units for radius?
What are the units for power?
Is there a proportionality constant?  If so what are its units?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/29/2007 08:52 PM
These are unitless multipliers to describe how the power gain and power output vary with size and B-field.  If you know the output at any given size and field, you can extrapolate the output at different size and field.

The EIXL and PBAL codes calculate actual power levels from a set of operating parameters, which include radius and B-field.  Those inputs and outputs have actual units.  The scaling formulae are just a part of those calculations.

As I understand it, WB6 operated fairly closely to the predictions of those codes, given the drive voltage, etc.  The best previous unit had missed the predictions, low by about a thousand times.  So the thinking is, WB6 proved the concept, at least at that scale, although only in short pulses, and it didn't last long enough to bring in any witnesses for confirmation.  Hence, the need to replicate the results and achieve longer run times with WB7.

And verifying the scaling holds will require building at some larger size.  But, in principle, scaling up WB6 by a given B field and radius would scale its output up accordingly.  Raising drive voltage would also raise output dramatically.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/29/2007 09:04 PM
Tony,

I want to see if ISDC or somebody else copyrighted the production of this particular presentation, and if I'm given any rights to use it.  If there is any trouble, I have no problem putting my PowerPoint presentation up with a voice-over, for example, and that would almost certainly make a better-looking production.  I'm not set up with a home studio, but if I can get a microphone cable back to the sound card, and keep down the interruptions for an evening or two, that can probably be dealt with.

I do have video production software on my computer at home.  It can work from video clips, but it does a much nicer job from stills, and I could certainly work from a mix of inputs.  I have not done any audio production work since college and WUVT, but I imagine it is like riding a bicycle ... you never forget.  Even easier now that I can drag and drop audio clips.

I might need some advice on formats.   Most of what I've made videos of so far have been DVD quality from relatively high-res still photos, so I've been working with high-end MPG formats.  Pinnacle's AVI files tend to crash the computer and are huge.  I can't produce WMV files with Pinnacle 10.  So the question is, what is a reasonable format, where to post the resulting very large file (50 minutes), and how to transmit it (FTP may be needed).

Maybe I could burn DVD quality and EMC2Fusion.org could sell copies on the website.

I have not tried it yet, but it looks to me like PowerPoint is rigged to carry a soundtrack, so it might very well do the whole job stand-alone and require a lot less bandwidth.  However, the audience would be limited to people who can view this format.

Or, if one of you has a good radio voice, and wants to produce it working from the ISDC talk, I'll happily send you the PowerPoint presentation.

I could really use an extra year this year!

Tom

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 09:31 PM
Codes... so this is not a simple scaling relationship.

WB5 didn't obey the scaling rule, falling short by 1000-fold.  WB6 did, but only in pulsed mode, and without any means of verification until WB7 is built.  Not sure I have alot of confidence in the scaling rule.  I think Bussard ought to prove that the scaling rule is correct, in addition to duplicating WB6 results and publishing a paper.  He could build a smaller reactor to prove the scaling rule, after deciding which design is best, the cube or the dodecahedron.  In fact, if the scaling rule is dependent on reactor design, it might be different for the dodec design than the cube design.  Might suggest smaller versions of each to prove their respective scaling rules.

I tried to find some info on the EIXL code, and I found a pdf paper at the following url describing a cylindrical IEC neutron source as a tool for non-destructive inspection of containers:

http://fti.neep.wisc.edu/iecworkshop/PDF/TECHNICAL_TALKS/wu.pdf

Pages 8,9,10 list fundamental formulas, but not the solver.  The solver would obviously be very complicated (maybe iterative forward difference formulas or whatever).  I'm leery of these methods because they are inexact.

Page 22 has a couple interesting charts, they look familiar but I'm not sure they really correspond to the wiffleball-type of reactor.

Page 23 has some parameters and includes fundamental units, but again I don't how to use them.  There's some other stuff in there.

This paper is probably not useful to anyone.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 05/29/2007 09:48 PM
Tom,

Selling somthing on the EMC^2 is a great idea! The only thing that would be missing would be the questions and answer session at the end of ISDC.  Were there any good questions??

There are two really smart guys originally from India that run CalEarth. They make the cheapest houses in the world out of dirt and a tube shaped fabric used mainly for flood control work. Their concepts are thought to be perfect for future lunar bases and mars bases.

http://news.yahoo.com/s/afp/20070525/ts_alt_afp/usenvironmentarchitecture_070525050758

When you talk to them about energy the last thing they want is centralized power and an another electric bill. They want something that can power an individual home. They like solar cells and windmills, or biomass etc.

http://news.yahoo.com/s/afp/20070525/ts_alt_afp/usenvironmentarchitecture_070525050758


That is why I think whoever comes up with the "fusion light bulb" is going to be the next bill gates. That is why I think going to higher power magnetic fields is key. Bussard was at .35 Tesla. I have an article on a japanese team that was at 51 Tesla for a few millionths of a second. Their magnet is the size of a penny. So something the size of a light bulb might be possible to build. Bussard says that you can't drive enough current through these small magnets. I don't understand that. I wish someone would explain it to me. I am not an electrical engineer.

I just found an interesting article on a new cryogenic heat transfer fluid. I don't know much about cryogenics either, but I thought you guys might find it interesting.

http://www.paratherm.com/Paratherm-CR/CR-Cryogenic-Liquid.asp?campaign=adwordsCR&gclid=COGmgZKotIwCFRoDhgod_ik3KA




Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/29/2007 09:57 PM
The fluid may have a lower vapor pressure than N2 making it easier to pump without cavitation.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/29/2007 10:08 PM
Semper,

Being leery of EIXL is healthy.  The whole success or failure of this depends on whether EIXL and PBAL are, in fact, correct.  They are not a full 3D model of the machine, and even then, I'd be leery.  I'm an empiricist.  I trust test results.

But I don't have access to the guts of either program, and would not be allowed to share them if I did.

This is probably a "show me the money" situation, but a chance to get up close and personal with the calculations is something a sensible investor ought to want to do.  Putting money behind better modeling, considering the improvement in computers, may be well worthwhile, too.  

Testing scaling with operating machines is the approach I trust, although at this point I might be inclined to try larger rather than smaller, if the money were available, just on the basis of being able to fabricate the magnets more robustly.  Smaller machines (tho' made with the improper geometry) have already been built and tested.  I believe they verified parts of the scaling, although they didn't make fusion so they could not verify the power output part directly.   I suspect a WB3 size (10 cm radius coils), with round cross section coils and proper spacing, might make a little fusion if it were decided to try smaller.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/29/2007 10:32 PM
So there must be tentative data for WB6 then.  Could you provide numerical data with proper units for WB6 that fills in all the variables in these formulas?

Fusion Power, a = (k1)*(B^4)*(R^3)
Drive Loss Power, p3 = (k3)*(R^2)
Power Gain = (k2)*(B^4)*(R)
Proportionalities k2 = k1 / k3
Power Gain = a / p3
Net Power = a - (0.2*a) - p1 - p2 - (0.2*a + p1+ p2) - p3 - p4 - p5

So the numbers I'm looking for are:

1.  Net Power = (watts).... probably a negative number for WB6!
2.  Power gain = (no units).... probably a very small number << 1
3.  B = magnetic field (Gauss)
4.  R = radius of the reaction volume (meters)
5.  a = total fusion power (watts)
6.  p1 = losses (watts) to Paschen discharges
7.  p2 = heat loss (watts) in the electrical power conversion grid ... make a guess!
8.  p3 = electric power (watts) required to drive the magnetic fields and electron guns
9.  p4 = electric power (watts) required to electrolyze water & compress hydrogen, and also purify boron-11 as fuel
10.  p5 = electric power (watts) required to run the vacuum pumps for the reactor chamber
11.  k1 = proportionality constant (as per Bussard 2006 IAC paper page 26)
12.  k2 = proportionality constant (as per Bussard 2006 IAC paper page 26)
13.  k3 = proportionality constant (as per Bussard 2006 IAC paper page 26)

Notice I distinguish explicitly between "Net Power" and "Power Gain".  The former has to account for alot more losses before it yields a positive value.  Sure wish I had some numbers to play with.  Voltages and neutron counts just don't provide alot of insight.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/30/2007 06:12 AM
Hi Tom,

As long as you have the presentation video generated you can upload it to Google Video. It would be in a good company.
Google says: "We're accepting digital video files of any length and size. ", "We accept AVI, MPEG, Quicktime, Real, and Windows Media"
Herre are  more details:
Currently, Google accepts videos in a wide range of popular formats. The fastest way to get your videos into Google Video is using our recommended specifications, such as MPEG4 format with MP3 audio or MPEG2 with MP3.


Technical Requirements:

- We accept many popular formats, such as AVI, ASF, QuickTime, Windows Media and MPEG formats. For example, .avi, .asf, .mov, .wmv, .mpg, .mpeg, .mp4, .ra, .ram, and .mod are all acceptable file extensions. Please note that we currently do not accept Flash files. Specific video codecs we accept include H.264, H.263, MPEG 1/2/4 and motion JPEG.
- The video must contain recognizable video content (video container files that do not contain video will not be accepted).
- The frame rate should be above 12 frames per second.
- The bitrate should be above 260 Kbps.


If you have a video in another format, we will do our best to interpret it.

Quality Recommendations:

If possible, we suggest uploading the original source file. However, we recommend the specifications below for maximum quality and reasonable file size:

- MPEG4 (mp3 or mp4 audio) at 2 mbps
- MPEG2 (mp3 or mp4 audio) at 5 mbps
- 30 frames per second
- 640x480 resolution
- 4:3 frame
- de-interlace


Title: Re: Fusion with space related aspects thread
Post by: pbelter on 05/30/2007 06:15 AM
They also have a desktop application recommended for uploading if the file is larger than 100 MB. Here is the link to the details

https://www.google.com/video/upload/UploadInfo?hl=en
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 05:37 PM
Wire resistance calculator:
http://www.smeter.net/electronics/wireskin.php

It is a DOS application so: - down load it and open it from your computer.

Dr. B in his lecture said he couldn't get enough current through his copper coils with water cooling. Had he gone to LN2 cooling coil resistance would have been reduced by a factor of 10. If output and gain scales as B^4 that indicates a gain and output improvement of 10,000. Even if an improvement of only 5X was possible due to external fixed factors you get an improvement of better than 600.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/30/2007 06:24 PM
Yes, LN2 cooling was starting to look pretty tempting in the later days.  WB6 was not set up for any kind of cooling.  Tony has been bugging us with an ultra-low (not quite superconducting) cold magnet technology using an aluminum alloy.  Dropping resistance is better than just cooling.  It reduces the heating!

I've got a friend who lives nearby.  He's not an amateur fusioneer, but he is one of Richard Hull's High Energy Amateur Science buddies, and is familiar with the technology.  He specializes in magnets, both copper and LN2 superconductor.  He says he holds a world record of some sort for field strength on copper magnets, and I've seen a special technique he uses for construction that involves copper ribbon and a ceramic matrix.  He believes a WB6-sized machine can be made with a field strength of 1-2 T, and run longer.

That alone ought to boost output by 10^4 or so.   That might get some attention.

Semper ... mind working.  I don't have all the numbers you are looking for, but the big dog is the electron power.  For WB6, at deep potential well conditions (presumably what it would draw at steady state), the emitter current was 14 amps and the accelerating voltage was 12.5 kV.  The emitters probably used about a kW or so for heat (there are new technologies such as diamond film that might almost eliminate this once the device is started).  

B field would have been a little less than 0.1T.  The magnet radius was presumably about 0.15 meters, 1/10 the size per axis of the proposed net power DD machine.  WB6 terminated the run by initiation of a Paschen arc, but a properly-running CW machine should not do this at all ... you try to keep the neutrals way below this level because a Paschen arc is so disruptive.  Lower background neutral levels will probably cause power loss by fast-neutral charge exchange, and this does need to be worked into a power balance.  I have no data on the problem, but it is not being ignored (cursed at, perhaps, but not ignored).

The power use of the magnets is not something I have on hand, but it would have been an abysmal addition to the power balance of WB6.  The hope is certainly much more efficient magnets, preferably superconductors, but even those have cooling energy demands, which must be included in any valid power balance calculation.

Work out the fusion power from the energy per fusion event, 3-something MeV, each eV 1.6e-19 joules.   There are 2 fusions per neutron from DD (half the reactions produce a proton).  The detector counted one neutron in about 13,000 produced, and the rate was about 3 counts in a quarter millisecond.  All told, the fusion power production of WB6 was around a quarter of a milliwatt.  Way the hell below positive net power.

Things to keep in mind when scaling up ... there's more than B^4R^3.  The potential well depth is typically about 80% of the drive potential (they ran a number of non-fusion runs on WB6 before attempting fusion, in part to verify this, also to quantify the other electron trapping properties).  I've mentioned that a fusor barely makes any fusion at 10 kV, and most machines are run at 40-60 kV or even higher.  Look at the cross section curves a few pages back and realize that WB6 would have perked up remarkably at higher drive voltage as well.  The voltage scaling depends on the fuel and where you are in the curve, so it is not a neat factor like R^7.

I don't have on hand all of Dr. Bussard's presumptions about the scale-up to net power from WB6, but I've run a straight R^7 on WB6, and it does not  reach 100 MW by simply scaling up 10X (1e7 scaling).  Some additonal factors are probably assumed.  A boost of about 5x due to going to a dodec may be included, and going to higher voltage is likely also assumed.  He may also have in mind a further reduction in loss area by eliminating those interconnects.  He may also have some data that indicate that WB6 was never run optimally ... very likely, considering how rough the ion production was.

I have a spreadsheet at home where I plugged in various numbers, but I didn't do a full net power calculation because I did not have enough data on hand.  Most of my calculations were with 2 meter radius, and plugging in various fanciful B field strengths I encontered.  Putting in the 13 T an ITER magnet was recently tested at produced a rather alarming power level.  I suspect that strong a field makes the device start having excessive effects on ion trajectory, but it was fun to run the numbers.

Title: Re: Fusion with space related aspects thread
Post by: jomo on 05/30/2007 07:21 PM
I am very happy to have discovered this thread. I was searching for information related to the google video that I literally "stumbled upon", and have since been hunting for news and background information about R.W. Bussard et. al. I also listened to the radio program last night featuring Tom Ligon and Bussard; this was also quite lovely.

I'm really happy to hear that an NPO has been started, Tom and others on this thread, have been so great, many thanks to you all for great dialog, and thanks for your patience Tom, in repeating many things over 50+ pages of discussion.

Anyhow this polywell fusion stuff is truly amazing! I am incredibly enthralled by it, and despite my lack of knowledge of details, and with the help of all the great animations and such (thanks for those), it really makes incredibly good sense !

I currently work in computer programming, although my background is in Ecology and Conservation biology, and more dimly behind that, chemical engineering.

Naturally, this new Electrodynamic fusion has peaked my interest for ecological reasons. Aside from it's absolute inherent coolness factor, and it's aesthetic beauty -- these magnetic orbs with little stars in them.

I was wondering a few things:

How long has the idea of pB11 fusion been around? How long have we known about this neutron-free reaction?

I wondered about the ethanol project. I've always heard that using land for fuel was always inherently counter productive, and I wondered, why bother at all to use one of these reactors to generate heat to help with the process of conversion of sugar to ethanol of crops... why use ethanol at all ?

I also wondered about the waste of these devices over the long term. I imagine that when coal and oil were first being used that people simply wouldn't have imagined that the continued use could affect the climate on global scale.

because at first glance it's amazing! (just 4He), too good to be true, and that got my "too good to be true" flag up.I wondered about what hundreds, perhaps (if it should prove to be so good) thousands of years of this technology rolling continuously, the energy demand ever increasing...

what sorts of wastes would we encounter?

If so much energy is injected into the system (earth) is there not an inherent increase in entropy? would the planet overheat simply by the heat generated by these things? Are the products trivial over the long term ? would there be a significant  increase in helium in the air after 1000 years of operation?  i Wondered if the overall energy budget of the earth would somehow be completely out of whack. Could we theoretically run out of B11?

The truth about people is that when we encounter some kind of technology that promises to be endless, humans really go to ballistic extremes. What would Las Vegas look like in an age of relentlessly cheap fusion power? would it float like cloud city ?

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 07:26 PM
Tom,

The minimum input energy required is the energy to accelerate p-B11 to fusion speeds.

It is 1.2 Mev to 560Kev effective collision velocity with a single accelerating voltage.

I'll see if I can attach the spread sheet.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 07:44 PM
jomo,

As we like to say in physics and engineering - have you run the numbers?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 07:47 PM
jomo says:

humans really go to ballistic extremes.

Sounds like a good idea to me. Space travel.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/30/2007 07:49 PM
Jomo ... thanks for your patience!  You plowed thru all 50+ pages!??  Wow!

Alcohol ... the primary advantage is you can use existing gasoline infrastructure.  Hydrogen production is also viable with fusion to produce it, but has no existing infrastructure so would be harder to get started.  I don't know if we are yet as good at storing energy in vehicles with hydrogen.

I've got a biology degree myself (in addition to engineering technology), and I agree with you that using agriculture to produce fuels is a concern, as it can put pressure on the environment and competes with food uses of agricultural land.  But more efficient use is certainly better than what we are presently doing with corn to produce ethanol.  I think Dr. Bussard is hoping to get some beneficial socialogical effect beyond just the fuel production, specifically improving life in the third world.  And at least it is not a fossil source.

It should also be possble to make alcohol from carbon monoxide using Fischer-Tropsch synthesis, from any carbon source including agwastes.

If we continue to expand the population on this ball of rock like we have historically, we'll be in trouble fusion or not.  Population control is critical.  I suspect it will occur naturally as more countries become prosperous.  The US is supposed to be very near zero population growth if you discount immigration, and the trend is supposedly common among developed nations.  In poor countries, having lots of kids is traditional, largely because it is the traditional "social security system".  But population control should be encouraged.  And tickets to the asteroid belt.

Finally, fusion should greatly reduce, and hopefully eventually eliminate, large-scale use of fossil fuels for fixed electrical power production.  Liquid fuel would be used primarily for forms of transportation for which it is best suited, long-range road vehicles and aircraft.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 08:02 PM
Tom,

We have a very effective means of population control predicted by Bucky Fuller 50 years ago and working well today:

When per capita income gets above a certain level people don't reproduce. Europe is a prime example. America too, except we make up for it with imports.

So the deal is: more energy slaves - fewer people.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/30/2007 08:08 PM
Quote
jomo - 30/5/2007  3:21 PM

 why use ethanol at all ?

JOMO welcome.
For various reasons liquid fuels will probably be around for another 50-100 yrs, longer in the 3rd world. Electric cars/trucks likely cannot replace all vehicles in the near future, though for commuting electric cars are coming of age.

So if by 2060 we can generate a few 100 gw of electricity, or even a 5,6,+ Terra watts, thru fusion, we will have some breathing room, as far as 1000 years of He.

Quote
Tom Ligon - 30/5/2007  2:24 PM
  A boost of about 5x due to going to a dodec may be included,


I recall the same from the google talk or maybe it was the Valencia paper. IIRC Dr. B said the truncated cube/dodec would see a 3 to 5 times improvement.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/30/2007 08:11 PM
More losses,

The 2.46 Mev alphas have different energy by a few hundred KeV due to the net momentum from the collision says the Google video. There  is a lot there if you know what to listen for. My hearing has gotten better over the last 6 months.

You know I was wondering about that. Any energy spread in the alpha products gets turned into heat.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/31/2007 12:16 AM
MSimon,

Geeze, picky, picky, picky.  There are three ways to go.

1) Provide a target that just intercepts the alpha as it runs out of energy.  If you tune it exactly to the most likely energy and there is any spread at all, half the particles will probably wind up short.

2) Provide a target that intercepts the alpha when it still has a little margin of KE left, and turn the excess into some heat,

3)  Provide a target that requires more energy to reach than the particle has, and it can't get there.  Zero energy results.

#2 is more efficient than #3 or even #1.

Dr. Bussard envisions a number of intermediate grids for the lower energies, but is a little vague about it other than figuring it will keep some engineers off the streets for a while.

I envision putting some collector plates in the shadow of the magrid, where the most energetic particles won't go because they'll tend to fly straight.  A modest magnetic field might be used to gently coax the weaker alphas, once they've climbed most of the potential well and have lost most of their energy, to turn to the collector plates.  This is like the energy-filter magnetic stage of a mag-sector mass spectrometer.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/31/2007 12:55 AM
Tom:

I'm not going to accuse anyone of misrepresentation, I like Bussard's idea and appreciate the efforts of enthusiasts to get the word out.  BUT, I've re-read Bussard's papers and I've come to the conclusion that everyone here is mistaken about the 1.5-2 meter radius Polywell achieving "net power".  In fact, Bussard states that such a machine might produce 40 MW of power, but I could not find anywhere that he claimed net power for this size machine.  The 1.5 meter radius DD-fuelled machine is simply the SMALLEST POSSIBLE STEADY-STATE MACHINE based on his scaling rule and the available magnet technology.  Like WB1 - WB8 it would also be an experimental reactor intended to quantify all of the losses at steady-state conditions (some of which I've listed).  His current pulsed reactor can't quantify these losses.

A net power reactor would be still larger.  We cannot yet estimate how large a net power machine would be based on Bussard's Polywell design.  I would recommend that everyone support the DD-fueled steady-state machine since it would be smaller, cheaper, and still run at steady-state.  Obviously the p-B11 reaction is attractive and the "still larger" net power machine should use that fuel, but we shouldn't waste money until we know that steady-state losses can be controlled and if net power can be achieved.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/31/2007 02:26 AM
Tom,

I'm an aerospace (aircraft) engineer. It is my job to be picky. LOL.

In any case Semper was looking for losses. I was just recently looking at particle momentum after fusion and Dr. Bussard gave a back of the envelope estimation in his google talk.

In any case if you go up thread quite a ways you will find my first estimate was 50Kev spread - based on a WAG. 200 Kev is quite a bit more.

The first operational plant will be lucky to get 50% of the fusion energy converted to electricity.

It is ITER's job to keep engineers busy. Our job is power to the people.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/31/2007 02:30 AM
"I would recommend that everyone support the DD-fueled steady-state machine since it would be smaller, cheaper, and still run at steady-state. Obviously the p-B11 reaction is attractive and the "still larger" net power machine should use that fuel, but we shouldn't waste money until we know that steady-state losses can be controlled and if net power can be achieved. "

At high power if p-B11 can be made to fuse it should be prefered due to radiation considerations in an experimental regime where you will want to be changing things around.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/31/2007 02:35 AM
Is that capability really worth an extra $50 million for an even larger reactor?  Some might argue that it is.  Honestly, I've read that ITER is more expensive than a DEMO reactor because it has extra capabilities for running experiments.  Maybe you are right.  But that would be an extra $50 million bucks.  Myself, I don't believe that kind of coin can be raised by a non-profit organization.  Inevitably Bussard's work will have to transition back to a government-funded operation if any steady-state machines are to be built.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/31/2007 03:04 AM
Semper,

Do you want to spend you $50 mil on idle time or on a bigger machine? It is a judgement call.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/31/2007 03:52 AM
I guess if the money were available I would say go with the smallest possible steady-state machine that can prove every conceivable scaling rule, loss mechanism, technical hurdle, etc.  So yeah, the 2-meter radius machine would do everything, either p-B11 or DD reactions.  If that size reactor would be the comprehensive proof then do it.  If the money were available then do it.  It would be better if there weren't some outstanding problem left to solve after spending so much money on a large reactor.

I guess every other fusion experiment in the world is doing DD or DT experiments.  It's the reason why ITER will never be viable, since the 30,000 tonne reactor will be left radioactive after decommissioning.  All the fission reactors worldwide produce 10,000 tonnes of radioactive waste annually.  After 10 years ITER makes 30,000 tonnes.  It really isn't progress is it?  If a different type of fusion system can eliminate the radioactivity problem, ie. the p-B11 fusion approach, then that's the way we should go.  It would break new ground, and if science has to be done, then let's do something that hasn't been done before.

Title: Re: Fusion with space related aspects thread
Post by: jomo on 05/31/2007 04:21 AM
I see, I see, ethanol would be a transitional fuel.
thanks all. hope this happens.
Title: Re: Fusion with space related aspects thread
Post by: jomo on 05/31/2007 04:31 AM
I was just rewatching parts of the lecture at google. While the first time I was just trying to follow the idea, this time, I realized that Dr. Bussard is quite a funny man! He's slippng jokes in there throughout; some are pretty cutting.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/31/2007 08:21 AM
Hypothetical Solved Problem for Bussard Polywell Net Power p-B11 Reactor:
---------------------------------------------------------------------------------------
The tentative formulas for power gain were given as:

Power Gain = FusionPower / DrivePowerLoss
Power Gain = (k2)*(B^4)*(R)

So the radius of the reactor volume would be:

R = PowerGain / (k2 * B^4)

By inspection of the photos of WB6 I estimated that the magnets would block 20 percent of the Helium ions and so 20 percent of the Fusion Power would be dumped as heat into the magnets.  At least the same amount of energy in the form of electricity would be required to run the heat pumps to keep the magnets cool.

If the reactor is generating 100 MW of Fusion Power with a Power Gain = 4, and the Helium ions can be captured by electrical conversion grids with 95% efficiency, then:

- 20 MW of Fusion Power is lost as heat due to Helium ion collisions with the magrid.
- 4 MW of Fusion power is lost as heat in the Helium ion capture & conversion grids.
- 76 MW of Fusion Power is converted to electricity.
- 25 MW of electricity is needed for Drive Power.
- 24 MW of electricity is needed for the heat pumps to cool the magnets and grids.
- 27 MW of electricity is available to run vacuum pumps, separate the exhaust gases, purify fuel for use in the reactor, and sell to the general public.
- A cogeneration system might be fitted to the heat exchanger.  The 24 MW of heat removed from the reactor chamber might be converted by a heat engine with 20 percent carnot efficiency generating a further 4.8 MW of electricity.

Can anyone tell me what the reactor radius would be to achieve a Power Gain = 4 using p-B11 as fuel?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/31/2007 09:29 AM
You are on the right track. The power for the MaGrid gets reduced  upon power operation due to He++ Conversion. I estimate a 7% return of the impinging power. About 1.4 Mw.

How do you get 25 Mw of drive power? Electron guns? The minimum drive at 200KV grid voltage is 1.2 Mev/fusion with a resultant of 8.68 Mev fusion energy. Of course there will be losses.

I think cooling can be done for a lot less that 25 MW pumping power if you can run high enough delta T. Fission nukes run at about 10 MW of pumping power so I'd say you are in the right ballpark.

I kind of like LN2 cooled Cu coils in a total loss system for experimental purposes. You will need Cu coils if you are going to warm up on D-D. They are also an easier step into p-B11 than going all superconductor from the start.

As far as the exhaust gasses. Condense out B11, Burn the hydrogen, Capture the He that remains.

You are only talking a few pounds of H2 per day. Even if you are paying $100/lb for highly enriched H2 (no D no T) it is not a significant expense. Burn it and you get H2O.

He remains.
Title: Re: Fusion with space related aspects thread
Post by: jomo on 05/31/2007 04:16 PM
Why burn the hydrogen ? just filter it out and recycle it
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 05/31/2007 04:59 PM
jomo,

It is very hard to separate helium fom hydrogen by ordinary physical means. The easiest thing to do is to burn it and save the water if you want to recycle the hydrogen. The burn separates it from the He which does not burn.

All in all the economics of recycling unless it can run totally unattended is probably not very good. It makes no sense for the prototype where conserving capital vs operating cost is critical.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 05/31/2007 05:16 PM
Hmm ... it would not be worth the bother, but if you're using liquid helium for the superconductor, even the boil-off ought to be enough to condense out the hydrogen from the exhaust.  

I think it would be better to use "waste cold" from the liquid helium system to augment either the liquid helium refrigeration or the liquid nitrogen stage.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 05/31/2007 06:45 PM
I don't understand this statement:

"The power for the MaGrid gets reduced upon power operation due to He++ Conversion. I estimate a 7% return of the impinging power. About 1.4 Mw."

I set the Power Gain = 4 and Fusion Power = 100 MW arbitrarily.  A Power Gain = 4 means that the Fusion Power is 4-times larger than the Drive Power.  By the following statement do you mean that a Power Gain of 8.68 / 1.2 = 7.2 is more realistic?

"How do you get 25 Mw of drive power? Electron guns? The minimum drive at 200KV grid voltage is 1.2 Mev/fusion with a resultant of 8.68 Mev fusion energy. Of course there will be losses."

Air conditioners for example use about the same power as they remove.  So I set the pumping power equal to the expected heat load.

"I think cooling can be done for a lot less that 25 MW pumping power if you can run high enough delta T. Fission nukes run at about 10 MW of pumping power so I'd say you are in the right ballpark."

If we are to believe Bussard's scaling formula then higher Power Gain results in less Drive Power for a desired Fusion Power.  Notice also that the reactor radius(R) is directly proportional to the Power Gain.  While higher Power Gain is desireable, a larger radius is not.  The best way to get higher Power Gain is therefore to use a higher magnetic field strength, since it varies Power Gain with the 4th power of the B-field.  Superconducting coils give better results than copper coils.  So going "all superconductor" will reduce costs while maximizing Power Gain.

"I kind of like LN2 cooled Cu coils in a total loss system for experimental purposes. You will need Cu coils if you are going to warm up on D-D. They are also an easier step into p-B11 than going all superconductor from the start."

Can anyone tell me what the reactor size would be if Power Gain = 4 ?
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/31/2007 09:04 PM
Quote
jomo - 31/5/2007  12:21 AM

I see, I see, ethanol would be a transitional fuel.
thanks all. hope this happens.

Ethanol would be popular in those countries that can easily grow sugar cane, not so much the USA.

Liquid fuels in general. They have certain advantages, including all those gas stations. Also 3rd world countries that dont have electric grids, really dont have a choice but for  liquids. Where here in the US, Bussard Fusion reactors can be plugged into the existing grid very easily, without overloading it, because we will have a larger number of Bussard generating stations. Instead of these huge generating stations transmitting power hundreds of miles, just put a Bussard reactor every... I dunno.... 100 miles. Think....... a decentralized generating infrastructure compared to what we have now.

We're still gonna need some (10-15+) terra watts generated by something new, (Fusion, solar, wind) by 2030 --2040--2050, fusion is the only one of those 3 that can be a base load supplier.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 05/31/2007 09:13 PM
Quote
SemperUbiSububi - 30/5/2007  11:52 PM

I guess if the money were available I would say go with the smallest possible steady-state machine that can prove every conceivable scaling rule, loss mechanism, technical hurdle, etc.  So yeah, the 2-meter radius machine would do everything, either p-B11 or DD reactions.  If that size reactor would be the comprehensive proof then do it.  If the money were available then do it.  


M.Simon has nicely made the case for incremental increases in reactor size, I think he does have a good point, but we shall see what the investors want. Since WB6 was about a ft sq.  It may be that WB7&8 should be too. And then maybe a 3 ft WB9, based on the results of WB7&8, we can guess how a 3ft WB9 should perform.

There I go putting the horse before the cart....
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/01/2007 12:02 AM
If all the steady-state losses can be quantified with a pulsed reactor, then why not do it with a 30 cm WB6-sized reactor?  That'll only cost $5 million, and it just might be possible for a NPO like EMC2 to raise the money.  Trouble is, I don't think all these things can be quantified with a small machine.

Otherwise a steady-state reactor will have to be built.  Bussard has stated that a minimum 2 meter radius machine is needed for p-B11 reactions at steady-state, and we'll have to take that on faith.  And that'll cost $200 million apparently.  There's no way an NPO will be able to raise enough money.  And there certainly isn't enough known to estimate the size of a net power reactor.

We're being asked to take alot on faith.  I'm not religious, and neither are most people when it comes to money.  Bussard really needs to put more data out there so people can understand where he gets his reactor size estimates, cost estimates, and how he rationalizes his conclusions.  If he doesn't want to do that, then maybe he should pass the torch to someone who is younger and more able to pursue this goal over the long-term.  That would provide a sense of continuity to potential investors.  He could stay on as a research partner or consultant.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/01/2007 01:20 AM
Semper,

There are a bunch of different issues I covered and probably confused you.

1. alphas hitting the MaGrid will depost energy based on the % of fusion alphas hitting the grid and the grid voltage.

2. Ultimate power gain is  ( fusion out  - minimum drive power ) / drive power  - reality will be less. Note that the net power gain calculated in the formula is the absolute maximum.  No matter the size of the reactor that is the very best you can do.

3.  If you do water cooling for the majority of the heat load you should have a pumping load of around 1/3 of  the heat to be transfered.  Cooling if it has to be done to 77 deg K or 4 deg K  depending on the kind of super conductor could run at 10X to 100X of the heat load.

I have to run a few errands. I may have more to add later.

Re: #1 I figured an average energy of 8.68/3 Mev per alpha (that quatifies the total per fusion) then you get a gain of the grid voltage times the charge  times the # of alphas (in arbitrary units). Which would be 400 Kev per alpha (probably a little more since you are running the grid at 220 to 250 KV to make up for well voltage loss.  Which is almost 14% of the alpha energy hitting the grid. Not bad.  In my previous calculation (where I got 7%) I had forgotten to multiply by the charge.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/01/2007 01:26 AM
Semper, skepticism is healthy, and you ought to be as healthy as a horse! ;)

Something like that could be what happens.

At the very least, the investors get to see the evidence you're asking about.  At this point, the only reason to hold any information back is so the investors get some reward out of this.

There was considerable interest at ISDC, including by people who can make things happen.  Let's give this a while and see if anything comes of it.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/01/2007 02:40 AM
Quote
Tom Ligon - 31/5/2007  9:26 PM

There was considerable interest at ISDC, including by people who can make things happen.  Let's give this a while and see if anything comes of it.

That sounds really good.

>sigh<
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/01/2007 02:52 AM
Semper,

On the gain thing. Suppose I have a transistor with a gain of 100. By picking the right resistors I can make an "amplifier" with a gain of .1, Pick some different resistors I can get a gain of 1. I can change resistors and get a gain of 10. However no matter what my resistor equations say I will never get a gain of 10,000.

Tom,

With the Monkton folks getting $5 million with a comittment of $40 mil. I'd say the rush is on. The field is now respectable.

Richard Hull should be on the review board. If he says "it was done" it should add a lot of credibility.

Laser instrumentation should be added to the budget.  Much more credible than Langmuir probes. In fact with the fusion rush on an instrumentation company might be able to make a few $$.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/01/2007 03:04 AM
I think I understand what you are saying.  I estimated the heat load at 24 percent of Fusion Power.  What you are saying is that net power is utterly impossible with superconductoring magnets because the electrical power needed to run the cooling pumps will be 10x the heat load, or 240 percent of Fusion Power.

Is this the reason you prefer copper magnets?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/01/2007 03:24 AM
I think a plant could be designed so that the heat load on the superconductors is minimal. You water  cool first to take most of the load. The plumbing gets very involved. The design gets tricky.

The reason for LN2 cooled copper besides ease of design and plumbing is that if you decide that you need to do D-D you can. Superconductors do not like neutron fluxes.

In other words LN2 cooling provides flexibility. Plus you can buy it by the truck load and have a 10,000 gal Dewar on site.

A "continuous" run need only be for a few minutes. Enough to prove "steady state" on human time scales. An hour would be better, depending on the cost of LN2.

Which why the smallest demo possible for the first "power" reactor is a very good idea.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/01/2007 03:32 AM
Tom, what can I say, the skeptic is always right!

Obviously I'm not involved with the research so I guess a little patience is needed.  I'm one of those guys who always wanted to understand everything in science and physics but most of what I've read hasn't exactly facilitated the educational process.  Going into the stacks in a university library for example reveals that most professional papers are no better than what Dr. Bussard has already published.  They're always short on details, especially numbers.  I really wonder if any of it has ever been reproduced by 2nd party research.  Proof-read perhaps, but reproduced?  I doubt it.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/01/2007 06:30 AM
M Simon,

A long time ago I worked in a lab that had a water-cooled thermocouple refrigeration system for a spectrophotometer.  It took a tube from a faucet and ran water across the hot end of the thermocouple and another tube went back to the sink and the hot water ran down the drain.  I believe it could reach temperatures as low as -70 deg. Celcius for single photon counting.  Now this is a long time ago and I may be remembering wrong, but could something like this replace the need for liquid nitrogen cooling?  It would be solid state, no plumbing required.  The thermocouple belts would simply be wrapped around the magnet coil at intervals.  The water cooling would be still needed obviously.  I don't know if it could get temperatures low enough for superconducting magnets, but it might work well enough to enhance the B-field of copper magnets.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/01/2007 09:38 AM
Semper,

Those "thermocouple" (actually a semi-conductor) coolers are very inefficient. Where the amount of heat extracted is small they make sense because of the cost of a refrigeration system.

When you get up into Kws or 100s of Kws mechanical refrigeration is the way to go - for an operational plant. For experiments the way to go is to buy the stuff and have it delivered.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/01/2007 09:53 AM
Guys,

Take a look at Indrek's latest simulations at:

IEC Fusion Newsgroup

He has electrons circulating  and shows well formation as well as "accelerator" formation.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/01/2007 12:33 PM
Ok.  Well, I guess I'll sit back and see what happens then.

One more potential application of fusion spacecraft is long-range intercept of potential Earth impactors.  I posted about this in another thread, so I'll give the link.  Fusion powered spacecraft might allow intercept of objects while they are still decades from perigee/impact.  Imagine trying to deflect Comet McNaught with only 5 months warning!!

http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=7716&mid=134436#M134436

Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/01/2007 05:24 PM
Quote
SemperUbiSububi - 1/6/2007  8:33 AM

 intercept of potential Earth impactors.


Or sheparding of an asteroid to an orbiting smelter at L4.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/03/2007 04:04 PM
Here is a link to one of Indreks latest Polywell simulations. With a great sound track.

http://iecfusiontech.blogspot.com/2007/06/electron-circulation-in-cubic-polywell_02.html

It shows the formation of the well and the multiple accelerators.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/03/2007 07:14 PM
Here is the cross section chart with log lines added. They go 2,3,4,5,6,8.

Tom says I should give the source of the chart. I got it up thread from one of Tom's Posts.

Tom says he got it from here:

http://fds.oup.com/www.oup.co.uk/pdf/0-19-856264-0.pdf

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/03/2007 10:02 PM
That's not good.  If someone copied that chart they wouldn't be able to figure that out.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/03/2007 11:51 PM
MSimon,

Where I posted that chart originally I give a link to the source data I used.  That might be a better starting point.

My computer security settings are giving me problems with those links to the Indrek pages.  I routinely keep Active X turned off.  I was wondering why I frequently didn't see anything interesting in the links you were giving me ... now I know.

I did manage to see the electron circulation animation.  It looks like a promising start.  It also gives you an idea of why doing 1e12 particles per cubic centimeter might be a rather serious load on a supercomputer.
Title: Re: Fusion with space related aspects thread
Post by: palebluedot on 06/04/2007 03:45 AM
Indreks 3D version of that simulation was pretty sweet too.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 04:17 AM
Semper,

Easy to figure out with some detective skills.

Paste it into paint do a read out of the line positions and it becomes obvious.

I'll try to see if I can get paint to work and do a better version.
Title: Re: Fusion with space related aspects thread
Post by: jomo on 06/04/2007 01:34 PM
Hi SemperUbi,

thanks for your figures:
- 20 MW of Fusion Power is lost as heat due to Helium ion collisions with the magrid.
- 4 MW of Fusion power is lost as heat in the Helium ion capture & conversion grids.
- 76 MW of Fusion Power is converted to electricity.
- 25 MW of electricity is needed for Drive Power.
- 24 MW of electricity is needed for the heat pumps to cool the magnets and grids.
- 27 MW of electricity is available to run vacuum pumps, separate the exhaust gases, purify fuel for use in the reactor, and sell to the general public

so does this mean that the net power output would be available from the last 27 MW? so out of that how much is available ?
and out of curiosoity what would be the fuel consumption in say production of 100MWh, which I assume is the reactor running for an hour.(if not, pardon my physics ignorance)
Title: Re: Fusion with space related aspects thread
Post by: jomo on 06/04/2007 01:41 PM
about recycling hydrogen:
is not hydrogen an expensive fuel? barring say using catalysts over fossil fuels to remove hydrogen, don't we get it from splitting water or reacting some expensive metals with acids ?

can't we react it with something that produces a less stable compound than water ? something less stable that would allow us to separate the gases, and then quickly free the hydrogen
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/04/2007 02:33 PM
Hydrogen is sufficiently cheap that they can afford to load about 106,000 kg into the external tank of the STS.

The amount used in a fusion reactor will probably be down in the range of some grams per hour.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 03:23 PM
Tom,

One small point. The Hydrogen wanted for an aneutronic fusion reactor would be highly purified. No Deuterium, no Tritium.

Still in the quantities required the cost would be miniscule compared to other operating expenses.

The same goes for Boron which would need to be highly purified. It should be noted that "depleted" Boron (almost all B11 very little B10) is common in semiconductor manufacture. Typically five nines or six nines purity is readily available. Lesser purities are of course cheaper.

Jomo,

I have some quibble with Semper's numbers. I have reviewed the pumping power question based on fission reactors. The pumping power required is on the order of 5% to 10% of plant electrical output. Which would put it at about 2% to 3% of plant thermal output.

Since the problems are similar for a Bussard reactor (although the proportions are different) I'd expect that for a 20 MW thermal load pumping power would run about 600 Kw to  1 Mw for a plant of around 100 Mw net output. Semper is high by a factor of 20 or more.

Second the ions impinging on the magnetic grid would deposit about 14% of their energy as electrical energy. So if 20 Mw of He ions are hitting the grid  the thermal load is only on the order of 18 MW.

I think he has the drive power high too. I haven't run the numbers (one reason is I don't know how much power is required for the electron sources) but I do believe it is high. Minimum (ideal) drive power is on the order of 15% of fusion power at the highest B11 cross section. At lower cross sections the (ideal) power is less. A real plant would not be run in that regime because control is unstable. In addition you must avoid the resonance capture region in the control regime as that would be another source of control instability. The useable cross section runs from about .02 barns to about 1 barn.

Depending on the reaction rates and other similar questions the control regime will look something like this: fuel injection for coarse/slow control and control of magnetic grid voltage for fine/fast control. Basically you have a dual loop problem. If the loops are properly interconnected (feed forward) it shouldn't be too tough.


Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/04/2007 06:33 PM
jomo,

I'm not an electrical engineer or a power engineer.  I'm an aerospace engineer.  As such my understanding of Bussard's, and any nuclear system, is limited to very basic fundamentals that I learned from university textbooks.  The point I was trying to illustrate was how little information we are given by Bussard in terms of a true thermodynamic analysis.  I've seen better analyses written up on solar trough concentators and they are simple compared to a fusion reactor, downright intuitive.  Seriously, what I posted on this message board is more information than Bussard has provided.  Right now, I can choose to take everything I'm reading from Dr. Bussard, Tom Ligon, M Simon, and others, on faith, or I can choose to sit and wait for the official equations and numbers.  I'd prefer the latter, but I don't believe it will be forthcoming due to the patent issue.  I'm at an impasse just because I really don't have a deep education on the subject and I'm not sure how far I want to go studying it.  It's interesting obviously..... but that's a side-effect of Bussard's inclination toward spacecraft propulsion.  I'm not nearly as interested in Focus Fusion, for example, and logically I should be.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 06:54 PM
Semper,

Assuming the physics is correct and the reactor will react, engineering estimates can be made re: the probable economic value of a reactor.

My caveats aside, your look at what might be possible is instructive.

BTW I have no Bussard connection or hot line. I rely on what Tom tells me and what I can find on the www. Every time I listen to the Google talk I learn something new.

I too am an aerospace engineer. I have the good fortune to have Naval Nuclear training which is my only leg up in this deal. Well, control engineering helps. Being semi-retired helps too. Lots of time to study.
Title: Re: Fusion with space related aspects thread
Post by: jomo on 06/04/2007 06:56 PM
Semper:  I am not even an aerospace engineer, but a humble web 2.0 programmer with an unused background in biology. I was just wanting to get an idea of what the 'net power' was, that's all. And I appreciate the fact that you took the time to calculate.

Tom: I suppose a few grams of hydrogen is not so bad. certainly not worth losing sleep about; obviously the space shuttle is a glutton for hydrogen, but you don't see millions of them going up...And launching one isn't cheap.  but if this technology works, there will be millions of these reactors.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 07:09 PM
Actually there will be more like 10s of thousands at the 100 Mw size. Total world electrical power use is on the order of 1E12 watts.

Assume 10 grams an hour/reactor.  That would be 100,000 grams an hour. Which is 100 kg per hour. About two tons a day. For the whole world. Say 10 tons when every one is powered up. The Boron requirements are about 10 times that - 100 tons a day. Not a big deal. Actuall Boron use will be less because it is easy to recycle. The hydrogen can be treated as if it was worthless. At least at the beginning.

Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 06/04/2007 07:13 PM
Quote
M Simon - 4/6/2007  10:23 AM

Tom,

One small point. The Hydrogen wanted for an aneutronic fusion reactor would be highly purified. No Deuterium, no Tritium.


That seems kind of silly--just how many neutrons are you going to get from D-D and D-T with normal hydrogen? Abundance of D is .015%, T even lower, though they have a much larger fusion cross section than p-B11, the neutron flux will be not insignificant I guess. It needs to be calculated out.

Quote

Jomo,

I have some quibble with Semper's numbers. I have reviewed the pumping power question
.
.
Second the ions impinging on the magnetic grid would deposit about 14% of their energy as electrical energy. So if 20 Mw of He ions are hitting the grid  the thermal load is only on the order of 18 MW.

I'd also question that 20% of the fp (fusion product) ions would hit the magrid, which is what he assumes. 1. you get some magrid deflection 2. at 2-3m radius the grid takes up a smaller surface area than for WB-6. So I think 20% is pretty unfair.

Quote

I think he has the drive power high too. I haven't run the numbers (one reason is I don't know how much power is required for the electron sources) but I do believe it is high. Minimum (ideal) drive power is on the order of 15% of fusion power at the highest B11 cross section. At lower cross sections the (ideal) power is less. A real plant would not be run in that regime because control is unstable. In addition you must avoid the resonance capture region in the control regime as that would be another source of control instability. The useable cross section runs from about .02 barns to about 1 barn.


Here I think you're drawing too much from fission plants. Control instability is not the problem you think it is, because this is not a chain reaction, the fusion rate at t=0+ is not dependant on the fusion rate at t=0. I think Bussard has said there is no real control problem once you get
steady state --the control problem comes with short-duration runs.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 07:30 PM
M Simon - 4/6/2007 10:23 AM

>One small point. The Hydrogen wanted for an aneutronic fusion reactor would be highly
>purified. No Deuterium, no Tritium.

That seems kind of silly--just how many neutrons are you going to get from D-D and D-T with normal hydrogen? Abundance of D is .015%, T even lower, though they have a much larger fusion cross section than p-B11, the neutron flux will be not insignificant I guess. It needs to be calculated out.


It is cheaper to take the neutrons out. Because of radiation shielding and because of neutron activation of reactor materials.

Here I think you're drawing too much from fission plants. Control instability is not the problem you think it is, because this is not a chain reaction, the fusion rate at t=0+ is not dependant on the fusion rate at t=0. I think Bussard has said there is no real control problem once you get steady state --the control problem comes with short-duration runs.

My basis for stating what I did was on a pure control theory basis. Any resonance in a control regime must be avoided because the control laws reverse. Reducing the controlled input can increase output. Very bad. A resonance in the capture cross section acts just like a resonance in the control system,

It is not too hard to get around. You have a minimum and a maximum drive voltage. You ramp up to past the minimum. You limit the drive to the maximum. What you do when the controller wants to operate outside the limits will be based on the effect on the plant.

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/04/2007 07:30 PM
Hydrogen would be for an aneutronic reactiion of protons and Boron-11, yielding three Helium ions and no neutrons.  That's why it's called "aneutronic".

How do you know the magrid would take up a smaller surface area for a 2-meter radius reactor than for WB6 ?  Remember WB6 ran in pulsed mode and didn't require liquid nitrogen and water cooling jackets around each magnet.  How much extra surface area would all that plumbing fill up?

It remains to be seen that 20% heat dump into the magnets is unfair.  My estimate was preliminary.  I'm waiting for Dr. Bussard to do a better analysis than I did.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 07:35 PM
Look at the graph again:

You are lowering the effective particle Kevs from 550 (maximum reactivity). You go down with voltage and reactivity decreases. You get to the resonance region and for a while lowering the drive voltage increases reactivity.  That is called a negative resistance. If there is enough negative resistance you no longer have a power reactor. You have a power oscillator.
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 06/04/2007 07:41 PM
Tom,

The link with your ISDC presentation no longer works. It was very good and it would be a shame if it lost its visibility. Can you consider posting it on askmar's site or elsewhere?
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 09:54 PM
everyone,

Doc has always answered my questions if I asked him often enough!

Question:

Dr. Robert W. "Doc" Bussard,
 
I saw your Google talk just yesterday. I was wondering if anyone had given you your 2 million yet.
 
Also how big a unit would need to be made to demonstrate a fusion rocket? I remember Von Braun predicting the fusion rocket would be developed before the fusion power plant.
 
Answer:

No - first the fusion power device, then the rocket engine.  We outlinbed a 10 year, 7 B $ program to do rocket engines, for MSFC, about 7 years ago, but no takers.  We had not yet solved all the physics problems.
 
As for the truncated etc, any polyhedron with an even number of faces around each vertex will do - it is a design matter of sizing the electrostatic droop holes and emitter standoffs - all in good time, given money.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:00 PM
Question:

I remember reading somewhere that Teller thought neutron catalyzed surface reactions were responsible for what came to be known as "cold fusion."
 
My question is: could a cheap neutron source help drive down the size requirement for Bussard's polywell device? (Below 2.5 meters)

Answer:

No.  The IEF is NOT a neutron chain reaction and does not depend on neutrons in any way.  It only relates to electromagnetic charge/mass ratio factors.  That is why pB11 can work - and it has NO neutrons.
 
As for Teller and cold fusion - I know nothing about Teller's views, but seriously doubt that neutrons had anything to do with it.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:03 PM
Clark,

As the designer of the Bigelow "log cabin" I can tell you that you are right on. And NASA should be spending 200 million on Bussard's Fusion device at Benson Space to develop a 3 weeks to mars fusion thermal rocket!
 
- Tony

Doc's Response:

YES!  Beyond the $ 200 M is the full engine development.  We (Dave Froning and I) laid this out in a proposal to MSFC about 12 years ago, in which we showed that the development of a real spaceflight engine at several thousand sec Isp, 100,000 lb thrust, would cost ca. $ 7B and take ca. 12-15 Years (NASA time).  This was before we had figured out the physics.  It is still a big job, but we ought to start before everyone gets Too Old!
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:07 PM
Doc,
 
What do I say to my mentor at Boeing, Billy Roeseler, that does not believe that you have all the science for practical, clean, net-power fusion? He is one of the smartest guys at Boeing for sure. He has over fourty years in as an Aerospace Stress Engineer. I can't believe that he doesn't believe it, if he has sat thru the entire 90 minute Google video, and read your papers and Tom's. I tried to explain to him that a quarter millisecond is steady state because it represents 100,000 ion circulations. But 4 neutron counts in that time period is equivalent to 16 million fusion events per second isn't it? Isn't that a world record for a 15 kv well? I tried to explain to him that it is a spherical collider, not a heat machine. I think it would really help if Nicholas Krall and anyone else could come out and publically support it too! He seems to want a group of eminent scientists to come out and support you. Once you guys rebuild the WB-6 machine and repeat the results for a longer period of time, I can't imagine anyone questioning it. Is that going to happen?
 
Tony

Doc's answer:

If we can get the restart funding (2-5 M over 1.5-2 years) we will build two small WB-6-like machines; WB-7,8 but improved over WB-6, and run each about 50 times.  Then we will have so much data that everyone will have to sit down and shut up.  We need this for the major review panel that we have planned to converne to review the whole thing, and recommend for or against.  This panel will be of peolpe at a level of the corporate management of the Boelings of the world, so will be bulletproof against silly objections.  But we need to get the restart funds and do the next small machine work - essentially repeating what we did in Nov 2005, but better, with more data.
 
The DD fusion output in the Nov 2005 tests was ca 1E9 fus/sec.  Each count represents about 1.4E4 neutrons.  4 counts is ca. 6E4 neutrons.  over 0.2 msec.  Divide one by the other and you get 3E8 neutrons/sec.  But only half of the DD reactions make neutrons, thus the DD reaction rate was ca. 6E8 fus/sec.  And the gas was not entirely D, some trace fractions of H were also there, raising the output, had it been pure D, to over 1E9 fus/sec.
 
Electron transit time across the machine is ca. 3E-9 sec, thus 2E-4 sec (0.2 msec) is about 1E5 transits.  A LONG time for the electron clocks.
 
I don't know Mr. Roessler, and have never talked with him.  So have no idea where he is getting his conclusions.  Dana Andrews is a beeter source, and probably brighter, as well.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:13 PM
Well the problem is that Bussard reactor is spiting out fusion products in all directions, or at least in the six directions permitted by the holes in the toroid magnets of the polygon electrostatic confinement device, so to use a direct converter you would need at least six decelerators sticking out of it like a giant jackstone, or a very large magnetic funnel to aim the particles into a smaller number of decelerators

this sounds complicated.

Doc's response:

I don't know who you are quoting, but it reads like he is repeating something from some work of Miley at U.Ill or Kulcinski et al at U.Wisc.  We have nothing to do with this magnetic tube stuff.  It is entierly too difficult.
 
We did a fairly detailed conceptual engineering design study of the Direct Conversion System (DCS) some many eyars ago, and presented it is a paper at the yearly STAIF conference in ABQ - I think it was in the mid-1990's but at the moment do not have it in front of me.
 
No, we do not use magnetic tubes to "focus" the fusion products i(FP) n the DCS.  The DCS is merely a set of concentric spherical grids surrounding the central magnetic field structure and system core, outsie this, and inside the containing spherical chamber.  Each grid is biased to successive higher voltages, and each taps off some of the energy of the particle flying throug the grid space.  Grid space is about 1-1.5 m in radial dimension, which is why the pB11 machines are so big with direct conversion.
 
The FPs are alpha particles, with charge of 2, at ca. 2.6 MeV so the whole grid system runs at ca. 1.3-1.5 MeV.  The FPs all come off spherically isotropic, so a fraction of them run into the main magnet containers (you can't twist fast ions with these fields), and heat the coil containers, which then must be cooled, as they are anyway for beremsstrahlung etc.  The design goal is to make the all-sky fraction subtended by the coils as small as possible, say 0.1-0.15.  Thus 10-15% of the FPs are lost to DCS.  The  rest can be slowed down by the external grids, etc, as always described.  
 
Simple in design and concept, but work to avoid arcs.
 
See the sTAIF paper, please.
 
Cheers, rWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:17 PM
Doc,
 
Can you use this technology on your Device?
 
http://www.spring8.or.jp/en/current_result/press_release/2006/060221-2#fig1
 
Fig 1. A miniature pulsed magnet attached to the sample-rod of a helium cryostat.
The magnet is cooled down to helium temperature together with a sample. This magnet is a solenoid type coil wound by AgCu wire; the outer part is reinforced by grass fibers. A Japanese 10 yen coin is on the right hand side of the magnet as a scale.

Doc's answer:

No.
 
RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:22 PM
Question from Billy Roeseler:


Dr Bussard, thanks for the reply.  We may be able to work together.
 
We also had some electrical engineers in our fraternity at MIT when I was there between 1961 and 1966.  I was in a 5 year masters program, decided to get out into industry in 1966 instead of going on for PhD.  Most of the PhD that I have known are full of themselves and not very well tuned in to reality.  But they tend to be slick and smooth, better able to convince buerocrats of their worth both in government and in industry.  Bill Gates stuck to technology rather than academics and changed the world.  Burt Rutan is the most accomplished engineer in my field, BS, AA, Cal Poly.  These two are not stuffy.  Paul MacCready is an example of a PhD who did not let his degree get in his way.  Perhaps you, Dana, Jay, Hans, Greg, Tad McGeer, and Andy vonFlotow are other examples.  My son, Cory, has only a BS ME from UC Santa Barbara, but he is more likely to set the world on fire than I am.
 
But if it is an accomplished EE we are looking for, I will send your ideas to Jerry Burnett, Rich Carpenter, Fred Luconi, and Tom Gerrity.  It doesn't do much good to sell me on the validity of your ideas, as I have no money.  But if you could get one of these EE interested, they may be able to help make the fusion engine work, commercialize it, and change the world.
 
This 100 kip engine with Isp>2000 that you want to build at a cost of $7B;  tell us about it.  How much does it weigh?  What are the main components?  How will you make chemical combustion go away?  What does your gigawatt terrestrial power plant look like?  What will be the cost of energy in 2020, 2040?  
 
GE is currently doing about $16B per year in combustion turbine power plants, over $1B per year in wind energy.  Why aren't they interested in your ideas?
 
Dave Penny is not only a bright engineer, but he is spiritually grounded and has literally moved mountains.  Seems to me it's just a matter of getting a critical mass of smart people together to make something happen.  Lou Tice and Lifespring teach us to visualize success, then let our subconscious work 24/7 to make it happen.  Success is fun.  True, we are getting older, but we still seem to be able to create miracles when properly motivated and inspired.  I feel another inspiration coming on!!

answer from Doc:

Dear Mr. Roeseler:
 
The first person I ever took the IEF idea to, for his critical comments and review, was my dear friend (new deceased) John Wyatt, at Pacific-Sierra Research Corp, in Santa Monica. He loved it.   John was the brightest intuitive physicist that I ever knew.  He left UCB after his MS work, because he couldn't stand the bore (to him) of the whole thesis process.  No matter.  The PhD means only what you put into it, and/or get out of the experience.  
 
Az for the mass etc of our space engine concepts - the best I can do is to refer you to the several papers we have published in the 1990-2004 period on this topic.  The last one was, I think, at the STAIF conference in ABQ, in Jan 2003, but there are others prior to that.  In general, we found that the engine concepts that use the IEF driver come in at about 1000x higher thrust/mass ratio than other systems for the same Isp, or give 1000x higher Isp for the same thrust/mass ratio.
 
The specific mass of the engine I mentioned is buried somewhere in our old proposal to MSFC, mid-90's or so.  Dave Froning (now lives in Flagstaxff) may recall this.
 
As for "GE" et al.  Of course they will continue to sell windmills, it is a good business, never mind the uneconomy of the cost of energy from such devices.  And CCGT power systems are great, the only problem is that they burn gas at high cost.  So what, everyone is making money on this stuff.  Why should GE gamble anything on futuristic stuff when the bottom line each year is still OK?
 
If we get it built, and it works, then they will buy it -- which is why we need the $ 200 M demo program -- which is why we need the first step $ 3-5 M restart R&D, to give us the base to kick off the demo program.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 10:24 PM
I can see how the electrodes should be arranged - lower voltage electrodes on the outside. The particle density going to those electrodes  is sufficient to create a virtual screen grid which tends to force (through the electrical field created) the higher energy particles to the higher voltage grid.

Take a look at my beam power tube link up thread.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:26 PM
If this reactor is ever going to fly, it still needs to be as light as possible. The vacuum chamber should be made of nonburnite/carbon-fiber composite. I don't think nonburnite outgasses much, if it did, it wouldn't make a good liquid oxygen tank in space.
 
The magnet configuration should approximate a sphere as closely as possible. When the magnets form a sphere the vacuum chamber can be a sphere. There has to be a better shape than this. I would think you would want as many small magnets as possible so you have lots of structural connection points between them.
 
http://en.wikipedia.org/wiki/Truncated_dodecahedron

Doc's response:

Just a short note to clarify some of your comments in re our interests in fusion and its development.  When we closed our Navy-supported EMC2 labs in Dec 2005, the Navy-owned equipment was to be sent for storage to USN/ChinaLake.  However, Ms. Dolly Gray, our President, suggested that it might be useful to some other local company with DoD contracts, if it couild be transferred to such a company.  Jim Benson's SpaceDev was local and had AF contracts for which the space chambers could be used, so - to avoid simply storing the eqpt - we arranged with Jim to transfer it to his company instead.  And he found that our three lab people were good acquisitions for his company's work as well.  
 
Thus, we managed to salvage almost a million dollars worth of government equipment for SpaceDev, in the hope that it could be used there.  SpaceDev has not, to this date, found an internal use for it, and it is thus not reassembled and available for use.  We had all hoped that DoD funds might be found to restart our own shut down work, which we had planned to conduct jointly with SpaceDev, but this proved not the case.  If we succeed in finding funds to support our restart we will likely put a new lab in Albuquerque, NM, near to the LANL, SNLA and AFRL, and build test setups tailored to the needs of the two new machines WB-7,8, that we hope to build and test in the first phase of the development effort..  
 
We have formed a new non-profit organization to accept tax-deductiblde donations for this work; it is EMC2 Fusion Development Corporation, under the 501C3 umbrella of the New Mexico Community Foundation (NMCF), at 343 E. Alameda, Santa Fe, NM 87501.  Contributions can be sent to NMCF at that address, marked for EMC2Fusion, and this will help us get going again towards the end solution of the oil problem.  In a week or so we will have a web site with more details.  I will send you the web address when it is available.  .  
 
Cheers, RWBussard
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/04/2007 10:27 PM
PBelter,

I'll see to it that Askmar has a copy of the presentation.  I'm hoping I can also find the time to do it with a voice-over.

Tom
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:29 PM
I thought Doc wanted the magnets for WB-8 to be in the form of a truncated dodecahedron.
 
http://mathworld.wolfram.com/TruncatedDodecahedron.html

doc's answer:

WB-7 = truncube; WB-8 = truncdodecahedron.
 
RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:32 PM
James Hopkins suggested that this hyperconducting wire has shown little resistance at liquid nitrogen temps. Does anyone know of a source for this wire or how it is made?
 
 
http://www.freepatentsonline.com/4927985.html

doc's answer:

I don't know of this "hyperconducting Al wire"..  Copper at LN2 is good, though, it has about 1/7 the resistivity of room temperature copper.  We always thought we could upgrade some of our water-cooled copper coil systems if we had the chance, by using an LN2 blowdown system to run for many seconds.  Never had the time or money, however.
 
Our non-profit is almost functional; the web site for NMCF lacks a direct place to note the destination of the contributions that are sought, but it does ask for a confirming e-mail msg in which one can specify the desired destination.  Once again, I attach a copy of the 1-page flyer about the non-profit Fusion Development Corporation.
 
Cheers, RWB/Doc
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:35 PM
If WB-6 was only .1 T, then even only 2 Tesla uncooled coils would mean that you could see something even from something from a trunc cube twelve inches on a side.
 
James Hopkins told me about somekind of "semi" super conducting magnet that works at liquid nitrogen temps and reduced but not zero resistance. Hopefully he will tell us more about it.

doc's response:

Solid state magnets don't work - you need air core magnets to get the field configuration needed.  An early paper from Poland tried to use solid state mags, but these will not work.  It was 1964 from a person at the Warsaw Reseasrch Institute.
 
WB-6 was about 1000 Gauss, 0.1 T.  Of course, higher fields would be better, but this takes more ohmic heating and thus lives shorter time.  We NEED the bigger machines.
 
As for setting up an investment thing - that is an SEC problem - our non-profit EMC2Fusion Development Corporation is a good thing as it allows people to support the work and get a tax deduction.  
 
Cheers, RWB/Doc
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:38 PM
What tesla level could be attained with a copper coil of circular cross-section, air core magnet, cooled by liquid nitorgen? And is a circular coil cross-section optimal? I thought you said something once about the cross-section conforming to the shape of the field.
 
http://hypertextbook.com/facts/2000/AnnaWoo.shtml

doc's answer:

It is limited by the maximum current density than can be pushed through copper with adequate cooling.  For water cooling of normal copper this is about 4-5000 amps/cm2 of cross-section.  If LN2 cooling is used, the current density can be raised by about 5-6x - but only for a short time (seconds).  
 
Round coils are nearly optimum.  they are good enough.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:41 PM
I am calling for an immediate 150 million dollar, five year program to finish the Bussard Fusion Device.

doc's response:

The best thing anyone can do is to start a chain letter seeking tax-deductible donations to our non-profit EMC2Fusion Development Corp (www.EMC2Fusion.org) to restart out R&D work and take it to conclusion.  
 
If 100 people would write to 5 successors, and they to 5 more, etc for 5 steps in the cahin, and if everyone would send in # 29, we would have over $ 6 M to get going again.  And THAT is enought o do a lot of advanced work, when done on the low-cost scale we have always followed.
 
Cheers, RWB/Doc

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:45 PM
From: Joel Rogers

 Dear Dr. Bussard,
>
> On fusor.net, Tom Ligon recently suggested that a precision leak might improve
> on the puff system. The startup would then be simple. Just open the leak a
> millisecond or so after the beginning of the pulse, and close it again after a
> preset delay.
>
> But there might be a problem with such a simple solution.


We must fill the machine is less than a msec.  Ionization goes swiftly because it is two-color - which Tom will recall - once the fast injected e's start the process, the low energy e's thus produced cascade being driven by the fast injected e's, and the whole thing cascades in very short time.  But we have to have enough neutrals in the machine to reach beta=one within a fraction of a ms.  This argues against a precision leak; which is way we used a fast-opening valve.  However, we did not have a fast closing valve with short enough timing to shut it off, and had too much gas in the supply reservoir.  Thus the glow discharge started outside within a short time after well formation, and the external unshielded leads arced to the tank walls.
 
Better insulation and better valving will do the trick, plus better design of the supply system.
 
Cheers, rWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:49 PM
For those of you that missed it last night, the link to the Ligon/Bussard invterview is at the bottom.

http://www.thespaceshow.com/detail.asp?q=709

doc's response:

It weas really Tom Ligon's show, and David Livingston asked me to call in.   I did not mean to take so much of Tom's time, though.  He is an eloquent spokesman with a stellar history in this work. And has just sold the story he has written to describe all this.   We can all read this in the December issue of Analog.
 
Your in-call questions were a whopper --- answering them will take about an hour of serious discussion.  Yes, it CAN do all those things, and that is why we have kept chasing it.
 
Meanwhile, once again I note that we DO have a non-profit charitable R&D organization set up to carry on the work, if we can get enough tax-deductible support from the people.  This would really be a People's Program for Clean power if sufficient money can be raised to get it going again.  Nobody gets rich, but the end of fossil fuels and energy politics can be achieved.  
 
Go to web site www.EMC2Fusion.org , and it will direct you to other useful things, including a donation button!
 
Cheers, RWB/Doc
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:52 PM
> > In regards to the gas system, wouldn't the ion-density begin decreasing as
> soon as the second valve closes?
> >
> > My concern is this: Unless constant neutron rate is measured, it does not
> follow that the small-scale results will scale to larger machines.
> >
> > How about using a submillisecond puff to get started, followed by a 100ms
> inflow from a precision leak?
> >
> >
> > Yours truly, Joel Rogers

Yes, but we have to watch the timing very carefully to avoid reaching glow discharge conditions outside too soon, which shuts the caps down.
 
The ions don't leak out very fast, once the well is formed.  We do need some gas input, but not much, once the thing is set uip.  In the short pulse mode, the whole thing is timing.  What we really need is to run it steady state , then we can control the relative flows properly. But this needs the bigger machiners and lots more power, and lots more money.
 
Cheers, RWB/Doc
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 06/04/2007 10:53 PM
Tony,

How old are these messages from Dr. Bussard that you're posting?  Some of them sound like they're from the early days of the EMC2 FDC set-up.

Incidentally, I think Dr. Bussard's plea for personal contributions is well-founded.  I know that a few people here have cited financial hardship at the moment, but most likely most readers could spare $50 or even $20... you spend that much taking the family out for pizza.

One thing that would help is for someone to make a page tracking the total donations to EMC2.  I've spoken to the folks at NMCF; they are happy (and required by law) to report how much has been donated to this project to anybody who asks.  We just need a good web developer with a bit of time on their hands, to periodically call them, get the total, and update a graph somewhere showing progress towards the goal.

I know I for one would love to see my $50 donation become a tiny drop in a very large bucket of inflowing donations.  :)

Cheers,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:54 PM
> "Short-pulse", as you call it in your email, seems too modest a term. A 100ms
> pulse is not "short" from the ion's point of view.
>
> Features of the "puff and leak" solution are: it is inexpensive, would be
> steady-state, and should work equally well in Phase-1 and Phase-2.
>
> Does the "not very fast" value of ion loss rate come from measurement or from
> theory?
>
> I'm just curious what is the main ion loss mechanism. Recombination? Charge
> exchange?
>
> Regards, Joel

doc's answer:

We have to avoiid charge exchange, and can do so only by nearly full ionization inside.  Main loss rate will come from upscattrer collisions that drive the ions up over the well edge.  This is not a big energy loss  Recombination is nil.
 
RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 10:57 PM
Paul,
 
I trust you have read the Valencia paper and seen the video. What is your degree in? What do you think is the critical arguement that invalidates Bussard's claims?

Yes, I have read it.  My BS is in physics and I studied Plasma Physics as a grad student at the Princeton Plasma Physics Lab in 1975-1976.  Haven't used much of either in the last 30 years because I made my living in an unrelated field in engineering.

I assume you have read the talk page on wikipedia.  For redundancies sake, it is at:
http://en.wikipedia.org/wiki/Talk:Polywell
Two things bother me a lot about Bussard's Polywell.  First is the lack of numbers.  Nothing on either energy, ion or electron confinement time or density.  No comparison with the Lawson criteria.  No information on the distribution of the plasm a, not even a photo of the glowing plasma that would give a density distribution.  From 1e9 fusions, we get 1.5 watts.  If he had D-T, then it would be about 10 times as much.  No idea what the drive current is, so can't calculate how far this is from breakeven.  This 1e9 neutron figure is from one shot and is the only number he gives to indicate any figure of merit for the device.  From this he boldly claims scaling factors which make p-B11 fusion feasible.

As for the plasma distributions, the discussions seem to indicate that the ions are attracted to the exact center of the device.  There is a volume of about half the size of the "box" of coils where the magnetic field is about zero.  Within this area, I believe that the election and ion density would be approximately uniform.  There is nothing in the exact center to attract the ions.  In addition, the fact that the electrons recirculate indicates that some of the electrons, an d thus some of the ions, are trapped on the field lines going around the coils.  Since a plasma shields electric fields, see Debye Length, all of the electric field that confines the ions is outside the "box" of coils.  So the ions are free to collide with the coils.

Fusion is easy.  Breakeven is very difficult.

doc's response:

Whoever this guy is, he hqsn't read the papers we have made available, not at all.
 
The "Lawson criterios" has utterly NO relevance in our machine - it is a construc t useful for Maxwellian LTE neutral plasma in equilibrium, like the mainline tokamaks.  We are non-LTE, non-equilibrium non-Maxwellian, and non-neutral.  Ours is a dynamic power amplifier, not an "ignition" machine.  That is what Langmuir and Farnsworth first figured out.  All we did was remove the bad grids.
 
The ions all go to the center because that is where the electron driven virtual cathode is found - negative potential attracts positive ions - high school physics.  Sorry he doesn't understand this.  Brian Edwards at U Ill in 1979 ran systems which showe 0.02 convergence ratiosn.  We did not have results from ONE test but from the final four before it imploded.  All showed the same neutron output.  At 10 keV the rate was over 100,000 times higher than anything Hirsch and Farnsworth got at the same energy.  
 
What numbers does he want.  It was running at beta = one - anyone can calculate what the density is for the surface field of ca. 1 kG.
  It was about 2.5 E 12 /cm3 at 10 keV.  We measured well depth, and had earlier measured conditoons for beta =- one.  We did not put the whole thing into the talks, papers and wb site.  We have a26 page paper on WB-6, which I am not going to put on the i-net.  It has too much proprietary stuff.
 
Of course, plasma shields e fields, but we have a non-neutral and non-equilibrium mixture, NOT a "plasma" in the PPPL sense.  If this person is interested, he should spend more time on the basic physics, otherwise he is just parrotting the mainline Maxewellian LTE objections that DO NOT APPLY.
 
Cheers, RWB
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 11:01 PM
Toni,

In terms of control, valves operate on milisecond time scales. They really are not fast enough to control the reactor. What is needed is control of the accelerator voltage as primary control and gas flow as a secondary control. Even the control of accelerator voltage will not be easy. You are talking about being able to do 20 or 30 KV swings in a few tens of microseconds at around 50 amps of current. You can do that with vacuum tubes as variable resistors, but that costs a lot of power. The alternative is a High Frequency Power Source that you can DC modulate. With diode rectification. It will take some effort. However, I believe at this time that it is a requirement.

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 11:02 PM
There are many ways to help the world AND achieve american energy independence. I hope you take the 90 minutes to watch the Bussard Google talk video and read his Valencia paper. Clean Fusion power can realistically replace all fossil fuel power plants in fifty years. But D-T Fusion can also transmute all existing fission radioactive waste in fifty years, instead of 250 thousand. Thermal Fusion can produce alchohol fuel from third world sugarcane crops for 35 cents a gallon to replace gas. The two sugarcane crops per year would end thirld world debt. OPEC won't care because Thermal Fusion can also desalt seawater so they can grow their own food. Eventually 100% electric cars will end all air pollution from cars. Couple that with no more burning of Fossil fuels and you have effectively ended all air pollution worldwide. I would also develop all the solar and wind power that is economical, because there is no single magic bullet. But Bussard needs 5 million now, alternative fusion research has been starved for the last twenty years. Whoever gets control of this technology can expect a return of 200 Billion per annum based on the 5 Trillion dollar world energy market.
 
Slavery was ended in britain with economic trickery. Imagine what you could do by breaking oil slavery economically!

doc's answer:

You pass it on, please.  It is a good summary.
 
RWB
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 11:05 PM
We could get the sugar for the gasohol with two crops a year from equatorial third world countries.

doc's response:

It is NOT "gasohol".  Gasohol is 10% alcohol added to gasoline.  It saves on gasoline consumption but does nothing to reduce smog, as the combustion temperatures are still so high that the bad NOx's are made to sting your eyes.
 
What the iEF cheap steam can do is make pure anhydrous ethanol.  This can be burned in any ICE designed to do so, and over 3 million cars in Brazil presently run on anhydrous ethanol.  No smop, because the combusiton temperature is lower than for gasoline, so no NOx's are formed.  It is less powerful than gasoline (70% the eneryg content per unit volume vs gasoline, and lower combustion temperature) but it works just fine.  Ford and VW have built these cars for Brazil and can make more as needed.  Anhydrous ethnaol fits the infrastructure of the gas distribution system without much modifucation; pumps, tanks, etc are mostlhy OK.  And it can be masw doe 35 cents per gallon.
 
Thus third world conutries become exporters of high value "oil" in the form of anhydrous ethanol.  
 
Gasoline can disappear.
 
And retrofit of existing oil, coal and nuclear plants can get them all on to IEF fuison power with minimal cost and shortest time to retrofit.  You don't need to build whole new plants, just replace the steam supply systems.
 
Cheers, RWB/Doc
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 11:10 PM
Toni,

Could you ask Dr. Bussard if he plans to use laser diagnostics as described in the Yoshigawa paper?
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/04/2007 11:26 PM
M Simon,

I looked up world coal use for a comparison, for 2004 I got 6.1 billion short tons. So now you can figure out how much uranium, thorium, and radon has been added to the atmosphere.

http://www.eia.doe.gov/aer/txt/ptb1115.html
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/04/2007 11:31 PM
Tony,

Re: the laser thing. I asked the Dr myself
Title: Re: Fusion with space related aspects thread
Post by: jomo on 06/05/2007 05:47 AM
I am very web saavy. I would be interested  to volunteer some time; I work with folk who specialize in "social media", basically blogging and that whole world of specialized rss, blog-search engines, etc.

I know that they would extol the power of a personal blog for spreading a message, it would be a great way to leisurely write some of those 12 years of research, while news readers around the globe pick up on new entries.

I could set up something simple that's easy to use and update frequently at no charge. whip up a graph tracking the NPO contributions.

If this sounds interesting to anyone who has anything to say in the matter: don't hesitate to contact me at will at stresslimitdesign period com.

Title: Re: Fusion with space related aspects thread
Post by: PMN1 on 06/05/2007 10:25 AM
The UK has largely gutted its coal mining industry but how many are dependent on coal mining (directly and indirectly) in other countries?

Same goes for Uranium mining and oil and gas for electricty generation?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/05/2007 07:48 PM
Due to an article I put up on Freeman Dyson

http://www.classicalvalues.com/archives/2007/06/freeman_dyson_g.html

the hit counter at  Mr. Fusion:

http://powerandcontrol.blogspot.com/2007/03/mr-fusion.html

Is spinning rapidly.

I saw a US Navy url in the referers log. I'm hoping that is a hopeful sign.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/06/2007 12:31 AM
I just put up a page on candidate solids that meet the Bussard criteria: an even number of edges at every vertex.

These are models you can rotate so you can get a feel for them. They are viewable as isometric wire frames as well as with solid faces.

http://iecfusiontech.blogspot.com/2007/06/geometric-solids.html
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/06/2007 01:28 AM
Has anyone done a 3-D computer model of WB6 ?  Should be easy.  I found a website a while back that did nothing but CGI of toruses.  I'd be great to get a 3D isometric showing the relative sizes and positions of all the components.  Might be better than photos, which are kinda dark, and from only one direction.

http://www.mailleartisans.org/articles/pics/6223hp402.jpg

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/06/2007 01:30 AM
Semper, this small version is what I used for my ISDC business card logo.

It doesn't stand against Tony Rusi and Skip Baker's chromed dodec.

MSimon, the "cubeoctohedron" is a truncated cube and truncated octohedron.  Play with it to realize that it is both 6-sided and 8-sided.  I ran into this recently when somebody sent me a design for an 8-magnet device and wondered why it would not work.  Short answer, it would.  Then I found a paper by Dr. Bussard that equated the 6- and 8-sided truncated figures for this purpose.  You go with 6 because it is two less magnets to build.

I imagine some of those higher-order figures may have the same property.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/06/2007 02:00 AM
Is that model properly proportioned?

Where would the electron guns and puff-gas injectors be positioned?  What do they look like?

What does the support structure look like?

How big is the vacuum chamber compared to the ring magnets?

If this thing is running, say in "star mode" how far out beyond the rings would the electron arcs project?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/06/2007 02:18 AM
Tom,

I kind of like the The Rhombicubeoctahedron  - all the faces are either squares of one size or triagles of one size.  Which ought to cut down the jigging required for prototypes.  The only difficulty I see is that opposing triangles are oriented with a 60 deg shift with respect to each other so the geometry will produce beams that are not congruent. This may not matter if all the faces are circular.

I was deep into geodesic math at one time so I'm really at home with this stuff.

Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/06/2007 10:15 AM
Another question...

Let's say this machine starts up.  Puff, and fuel ions are injected.  At first fusion reactions are vigorous, but as the density of fuel ions decreases, the lifetime of the unreacted ions starts to increase.  If this thing is running at steady-state, is it possible that some ions might never react?  If more fuel gas is continually injected to replace that which has reacted, but always with some ions left over from the previous run, is it possible that leftover ions would slow down and become thermalized?  Could unreacted ions build up with time and even neutralize the electron cloud and shut down the machine?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/06/2007 04:16 PM
Rand Simberg is discussing the Bussard Reactor:

http://www.transterrestrial.com/archives/009143.html
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/06/2007 06:33 PM
Some people have referred to an expert who wrote a damning paper about IEC fusion and how it would never yield fruit.  Well, here it is:
-----------------------------------------------------------

Todd H. Rider, "A general critique of inertial-electrostatic confinement fusion systems", M.S. thesis at MIT, 1994.

Download Full Text (2.2 MB)  http://dspace.mit.edu/handle/1721.1/29869

Todd H. Rider, "Fundamental limitations on plasma fusion systems not in thermodynamic equilibrium", Ph. D. thesis at MIT, 1995.

Download Full Text (18.2 MB)  http://dspace.mit.edu/handle/1721.1/11412

------------------------------------------------------------

I'm not a nuclear physicist, but after reading about Bussard's work my first counter-argument of Rider's theses is that some of what he states as "fundamental limitations" actually seem to be design-based.  Specifically, his paper's were written in 1994 and 1995 and are based on reactor designs up to that era.  For example, by changing the reactor design, Bussard claims to have bypassed the cusp-loss problem cited by Rider.  Therefore improvements in technology may partially or wholly invalidate Rider's thesis.

I do have concern however about his criticism that a p-B11 reactor such as Bussard's proposed Polywell requires two fuel species accelerated by a single potential well.  Due to the different masses and charges of protons versus Boron ions, these fuel species will have inherently different velocities, and this may constitute 'thermalization' from time = 0.  Also, as the clock ticks away in steady-state (which requires a much larger reactor than has been built), some ions would not be reacted, and might have time to interact kinetically so as to create a spread of velocities, i.e. thermal equilibrium.  This might further prevent a large fraction of the reaction mass from achieving the velocity necessary to achieve fusion, lead to stagnation, charge equilibrium, and reactor shutdown.  The power needed to overcome this "spreading of velocities" would be another steady-state loss mechanism.  It is hard to imagine that this problem, as well as all the other steady-state loss mechanisms, such as the energy balance, cooling requirements, scaling rules, vacuum losses, etc., can be proven using a small pulsed reactor.  This is why a small steady-state machine, say a 2-meter radius p-B11 machine, should be built.

Bussard may have a rebuttal to these criticisms.  It would be good if he addressed Rider's criticisms directly in whatever papers he chooses to publish in the future.

Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 06/06/2007 07:44 PM
Quote
SemperUbiSububi - 6/6/2007  1:33 PM

Some people have referred to an expert who wrote a damning paper about IEC fusion and how it would never yield fruit.  Well, here it is:
-----------------------------------------------------------

Todd H. Rider, "A general critique of inertial-electrostatic confinement fusion systems", M.S. thesis at MIT, 1994.

Download Full Text (2.2 MB)  http://dspace.mit.edu/handle/1721.1/29869

Todd H. Rider, "Fundamental limitations on plasma fusion systems not in thermodynamic equilibrium", Ph. D. thesis at MIT, 1995.

Download Full Text (18.2 MB)  http://dspace.mit.edu/handle/1721.1/11412

------------------------------------------------------------

I'm not a nuclear physicist, but after reading about Bussard's work my first counter-argument of Rider's theses is that much of what he states as "fundamental limitations" are actually design-based.  Specifically, his paper's were written in 1994 and 1995 and are based on reactor designs up to that era.  For example, by changing the reactor design, Bussard has bypassed the cusp-loss problem cited by Rider.  Therefore improvements in technology may partially or wholly invalidate Rider's thesis.

I do have concern however about his criticism that a p-B11 reactor such as Bussard's proposed Polywell requires two fuel species accelerated by a single potential well.  Due to the different masses and charges of protons versus Boron ions, these fuel species will have inherently different velocities, and this may constitute 'thermalization' from time = 0.

who cares if they have inherently different velocities? You want the p to hit the B11 ("you want the pee to hit the bee") ;)  with a combined velocity at or around the peak of the fusion cross section, or thereabouts. This is good, because rather than having to speed up heavy B11, most of the speed comes from the light proton.


Quote
Also, as the clock ticks away in steady-state (which requires a much larger reactor than has been built), some ions would not be reacted, and might have time to interact kinetically so as to create a spread of velocities, i.e. thermal equilibrium.  This might further prevent a large fraction of the reaction mass from achieving the velocity necessary to achieve fusion, lead to stagnation, charge equilibrium, and reactor shutdown.


This is true of electrons but not ions(fuel). You want the electrons to stay fast, because that keeps their capture cross sections low, and inhibits braking radiation and thermalization.

Ions, on the other hand, can start at zero velocity at the edge of the well and reach fusion speeds by the middle. So whether they are freshly injected or on their 20000th transit, their liklihood of fusion is the same.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/06/2007 09:43 PM
Quote
SemperUbiSububi - 6/6/2007  2:33 PM

Some people have referred to an expert who wrote a damning paper about IEC fusion and how it would never yield fruit.  Well, here it is:
-----------------------------------------------------------

Todd H. Rider, "A general critique of inertial-electrostatic confinement fusion systems", M.S. thesis at MIT, 1994.

Riders paper speaks to IEC fusion as it existed at the date of his papers publication, 1994. Since 1994 Dr Bussard has done quite a bit of new research. I completely fail to understand how Riders paper has any bearing on any work done by DR Bussard since 1995. HAs Mr Rider updated his work since 2005?

Quote
SemperUbiSububi - 5/6/2007  9:28 PM

Has anyone done a 3-D computer model of WB6 ?  Should be easy.


I have a 3d rendering program called Anim8tor. Since I just got Anim8tor I am not comversant with it. I would like to use Anim8tor to illustrate formation of the potential well in a WB6 type device. Since Tony's dodec was done on a CAD program, he might be able to animate it.

Quote
PMN1 - 5/6/2007  6:25 AM

The UK has largely gutted its coal mining industry but how many are dependent on coal mining (directly and indirectly) in other countries?

Same goes for Uranium mining and oil and gas for electricty generation?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/07/2007 02:32 AM
Semper,

The model of the truncube I posted up there is correctly proportioned for a business card. ;)

In the photo below, I'm holding a magrid just a little smaller than WB6.  Its proportions are determined by the size of foam wreath cores available at my local arts and crafts store.

Skinnier magnets are better, if you can manage it.

The most recent machines have all had emitters located on the corner cusps.  The electrostatic field shape on the corners is somewhat better for extracting electrons from the emitters.  Most emitters are cylindrical (dispenser cathodes, etc), but I've used arrays of car headlight filaments to do the job.

If you can see the puff gas system, it is not well made.  It should be an inconspicuous tube squirting gas (as a molecular beam) across one or more inside faces of the magrid.  It would feed from a high voltage insulator on the outside of the chamber ... if I were setting it up, the high voltage lead powering the magrid anode surface would be a tube that also carries the deuterium in.

WB6 was supported by four long tapered insulators that mount to the bottom magnet.  Two of these carry the magnet power conductors.  Small cylindrical projections hold the magnets apart (by several gyroradii at their closest points)  and provide the interconnection paths.  I would be interested in trying a structure with no interconnecting cylindrical bits, and instead support each magnet from the outside using the big insulators.   That's on the bet that the little cylindrical pieces still represent an electron loss path.

The picture on the right of Dr. Bussard's website top row of photos is WB6 in the chamber.  I'll tell you for a fact that the inside diameter of that chamber is 6 ft (I spec'd it).  So scale from that and you'll get pretty much what Dr. Bussard thinks is proper proportions.  The proportions of WB6 did allow the electrons to recirculate freely.  On some earlier machines (WB2 and 3) the Faraday cages were too close to allow this, although the electrons should slow as they approach the cage and turn back toward the magrid.  (The electrons are born at the potential of the Faraday cage and don't want to return to it.)  http://www.emc2fusion.org/

If the ions would live sufficiently long and make enough passes without fusing, they would no doubt thermalize, or at least lose energy.  This will also happen if the density is allowed to get too high.  The key is achieving a density profile where high-energy collisions occur in the center at fusion energies, very low energy (and thermalized) collisions occur in the high-density ion turn-around zone near the magrid, and very few other collisions occur.  A narrow range of optimal ion lifetime versus fusion density exists for any given size of machine and set of operating parameters (too high, thermalize, too low, too few fusions).  Larger sizes are required for that optimal density to produce net power.

The thermalized turn-around zone is a key to killing two of Rider's objections.  Rider believes A) the plasma will maxwellianize, and B) because it is maxwellian, some of the ions will upscatter in energy by collisions and so be able to exit the potential well complety.   The outer collision zone does have maxwellian properties, but at very low energy levels, so it essentially removes the scatter in the energy of the fuel ions on every pass, essentially resetting the population to all near zero kinetic energy.  Thus, thermalization keeps the machine from thermalizing.

Rider thinks the machine will have excessive bremsstrahlung losses.  Bussard and Krall counter that the central region Rider thinks will cause bremsstrahlung due to mutual repulsion is actually a convergence zone for both electrons and ions.  The electrons are making a virtual cathode that attracts ions, the ions make a virtual anode that attracts electrons, and the whole zone is never all that far from a neutral plasma.  Control of virtual anode height controls the bremsstrahlung problem.

All of this says you need very good control of the ion population.  WB6 and that puff gas system did not offer such control ... I suspect the system put in roughly the amount of gas needed, initially, but the amount continued to rise.  Fusion occurred in the short period during which the right density profile existed.  A successful machine will need to hold that condition.

It may be that it will occasionally be necessary to stop the reaction and clear the machine of junk gas, which may include fusion products in a power reactor.

Rider's final objection was dead-on right ... for HEPS, PXL-1, and WB-5.  Cusp losses of electrons in a box machine are too high.  They are irrelevant in a magrid machine.  Electrons lost out the cusps come right back in.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/07/2007 03:54 AM
Quote
If the ions would live sufficiently long and make enough passes without fusing, they would no doubt thermalize, or at least lose energy.  This will also happen if the density is allowed to get too high.  The key is achieving a density profile where high-energy collisions occur in the center at fusion energies, very low energy (and thermalized) collisions occur in the high-density ion turn-around zone near the magrid, and very few other collisions occur.  A narrow range of optimal ion lifetime versus fusion density exists for any given size of machine and set of operating parameters (too high, thermalize, too low, too few fusions).  Larger sizes are required for that optimal density to produce net power.

The thermalized turn-around zone is a key to killing two of Rider's objections.  Rider believes A) the plasma will maxwellianize, and B) because it is maxwellian, some of the ions will upscatter in energy by collisions and so be able to exit the potential well complety.   The outer collision zone does have maxwellian properties, but at very low energy levels, so it essentially removes the scatter in the energy of the fuel ions on every pass, essentially resetting the population to all near zero kinetic energy.  Thus, thermalization keeps the machine from thermalizing.


I understand that the ions zip back and forth between the outer magrid and the central electron cloud.  But what do you mean by "high-density" ion turn-around zone near the magrid?  Isn't the high-density ion zone in the central area?  Are there two high-density ion zones?  Or are you saying that there are more ions in the thermalized turnaround zone than in the central fusion zone?  Sorry if I need to visualize every little detail.

Also, if ions can collide in the low-energy thermal zone, and also in the high-energy fusion zone, why can't they collide somewhere in-between?  Bussard himself said that these ions are always interacting and that's why the system was so difficult to simulate computationally.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/07/2007 06:20 AM
Semper:

Quote
The key is achieving a density profile where high-energy collisions occur in the center at fusion energies, very low energy (and thermalized) collisions occur in the high-density ion turn-around zone near the magrid, and very few other collisions occur.

Thus the carburetor reference.
Title: Re: Fusion with space related aspects thread
Post by: SemperUbiSububi on 06/07/2007 09:56 AM
Ok, I'm looking at Bussard's 2006 IAC paper, Figure 15, page 14.  This chart is very hard to read, but the right hand side of the chart has a scale that appears to be labelled "Log of Particle Density", and the scale on the bottom appears to be "Radius".  It appears to be a plot of four different things, and to be honest I can't read which is which?!  For three of the plots there is a drop in density between 0.03 < R < 1.  Is this the "ion density profile" you are referring to?  If so, was this achieved by accident, or what?  How is this done?  It'd be great if that chart could be cleaned up a bit.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/07/2007 10:23 AM
Everyone,

I just saw this TV ad with Martin Scorsese and Ellen Degeneris. It was for American Express. They are donating 5 million dollars to some worthy cause. We should do this for Bussard.

http://www.membersproject.com/intro.htm

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/07/2007 11:57 AM
I personally talked to President Bush about government funding. In my dreams last night. He left before I could explain everything. Dang.
Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/07/2007 02:41 PM
I think it would be a great idea if AskMar make a pretty make up job in the Bussard´s IAC Valencia paper as he has done in other papers. Just for the graphs. It is a question of image; to create good impression. And it will be worthwhile for searching external great investors. Sorry for the comment but if a paper try to be a breakthrough it must have highly elegant in graphs. It is just a suggestion



Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/07/2007 06:02 PM
Semper and jlumartinez,

Dr. Bussard definitely needed office help on that report.  There are a whole family of graphics dominated by yellow streaks in that thing that must have come from an improperly set-up digitizer.

In this case, the original word document is almost certainly in good shape.  All that should be necessary is to re-scan the bad graphics.  I think it would be well worthwhile.

I can't make that particular plot out myself, but it is something called a "nose plot", based on the nose-shaped feature on the right side.  I've probably got some other examples at my disposal, and will see if there is something I can scan and post.  Then we can dissect it.

Nose plots are a primary output of the EIXL code, and are used to predict where that sweet spot is in the parameter space.
Title: Re: Fusion with space related aspects thread
Post by: pbreed on 06/07/2007 08:15 PM
I'm having trouble resolving the Bussard concept with the Rider paper.

A Simple thought experiment....
In the center where things fuse...

If two Ions collide we have fusion.
If the two ions have a close miss they will transfer energy between themselves.
One ion will gain some energy and one will loose some energy.

What keeps the ion with the gained energy from leaving the system and being an energy loss?
(Wouldn't this interaction tend to thermalize the ions?)


Given the cross section of area where the ions interact the fusion cross section is much smaller than the energy trading interaction zone.

So many more ions will have energy trading interactions than will actually fuse.


So why don't the ions as a whole thermalize?

I would really like this concept to work, but it seems almost too good to be true.



Title: Re: Fusion with space related aspects thread
Post by: jstrout on 06/07/2007 08:47 PM
Quote
Tony Rusi - 7/6/2007  4:23 AM
I just saw this TV ad with Martin Scorsese and Ellen Degeneris. It was for American Express. They are donating 5 million dollars to some worthy cause. We should do this for Bussard.

http://www.membersproject.com/intro.htm
I agree.  I've signed up for the Members project, and would be happy to propose this.  We need a compelling 1-paragraph description of the project.  Also, along with the project is a short bio of the person proposing it — if anyone has more impressive credentials than me (I have only an M.S., and it's in neuroscience), maybe they should do it.  Let's get our act together here first, agree on what we're going to do, and then do it there.

Also, note that there are currently over 500 projects in the "Environment & Wildlife" category (which I think is the best suited for this project).  Even if you sort by rating, there are page after page of perfect 4-star ones.  I'm not sure how to get our project noticed among the general membership.  But it would certainly help if we all pulled together to support it.

Best,
- Joe

Title: Re: Fusion with space related aspects thread
Post by: jstrout on 06/07/2007 08:52 PM
Actually, maybe somebody has already posted this?  (Though if so, they haven't done a stellar job...)

   http://www.membersproject.com/Environment_Wildlife/1869

Who is this "mogreen" guy and what is he selling?

There's also this one:

   http://www.membersproject.com/Other/3960?search=true

...though it's not clear exactly what this guy has in mind, either.  One advantage we'll have over most projects I've browsed so far, is that we have a very specific project in mind with very tangible benefits.  A lot of the "projects" here are very nebulous, with no clear idea what to do with the money.

Best,
— Joe
Title: Re: Fusion with space related aspects thread
Post by: jomo on 06/07/2007 09:00 PM
look at this : http://www.worldpress.org/Americas/2812.cfm

this is why regardless of the price of production of ethanol production with a fusion reactor, politically and economically, transforming food into fuel is not a good idea.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/07/2007 09:24 PM
pbreed, welcome, I think Tom covered that here:

http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5367&start=886

Quote
Tom Ligon - 6/6/2007  10:32 PM

Semper,

The model of the truncube I posted up there is correctly proportioned for a business card. ;)

In the photo below, I'm holding a magrid just a little smaller than WB6.  Its proportions are determined by the size of foam wreath cores available at my local arts and crafts store.

Skinnier magnets are better, if you can manage it.

The most recent machines have all had emitters located on the corner cusps.  The electrostatic field shape on the corners is somewhat better for extracting electrons from the emitters.  Most emitters are cylindrical (dispenser cathodes, etc), but I've used arrays of car headlight filaments to do the job.

If you can see the puff gas system, it is not well made.  It should be an inconspicuous tube squirting gas (as a molecular beam) across one or more inside faces of the magrid.  It would feed from a high voltage insulator on the outside of the chamber ... if I were setting it up, the high voltage lead powering the magrid anode surface would be a tube that also carries the deuterium in.

WB6 was supported by four long tapered insulators that mount to the bottom magnet.  Two of these carry the magnet power conductors.  Small cylindrical projections hold the magnets apart (by several gyroradii at their closest points)  and provide the interconnection paths.  I would be interested in trying a structure with no interconnecting cylindrical bits, and instead support each magnet from the outside using the big insulators.   That's on the bet that the little cylindrical pieces still represent an electron loss path.

The picture on the right of Dr. Bussard's website top row of photos is WB6 in the chamber.  I'll tell you for a fact that the inside diameter of that chamber is 6 ft (I spec'd it).  So scale from that and you'll get pretty much what Dr. Bussard thinks is proper proportions.  The proportions of WB6 did allow the electrons to recirculate freely.  On some earlier machines (WB2 and 3) the Faraday cages were too close to allow this, although the electrons should slow as they approach the cage and turn back toward the magrid.  (The electrons are born at the potential of the Faraday cage and don't want to return to it.)  http://www.emc2fusion.org/

If the ions would live sufficiently long and make enough passes without fusing, they would no doubt thermalize, or at least lose energy.  This will also happen if the density is allowed to get too high.  The key is achieving a density profile where high-energy collisions occur in the center at fusion energies, very low energy (and thermalized) collisions occur in the high-density ion turn-around zone near the magrid, and very few other collisions occur.  A narrow range of optimal ion lifetime versus fusion density exists for any given size of machine and set of operating parameters (too high, thermalize, too low, too few fusions).  Larger sizes are required for that optimal density to produce net power.

The thermalized turn-around zone is a key to killing two of Rider's objections.  Rider believes A) the plasma will maxwellianize, and B) because it is maxwellian, some of the ions will upscatter in energy by collisions and so be able to exit the potential well complety.   The outer collision zone does have maxwellian properties, but at very low energy levels, so it essentially removes the scatter in the energy of the fuel ions on every pass, essentially resetting the population to all near zero kinetic energy.  Thus, thermalization keeps the machine from thermalizing.

Rider thinks the machine will have excessive bremsstrahlung losses.  Bussard and Krall counter that the central region Rider thinks will cause bremsstrahlung due to mutual repulsion is actually a convergence zone for both electrons and ions.  The electrons are making a virtual cathode that attracts ions, the ions make a virtual anode that attracts electrons, and the whole zone is never all that far from a neutral plasma.  Control of virtual anode height controls the bremsstrahlung problem.

All of this says you need very good control of the ion population.  WB6 and that puff gas system did not offer such control ... I suspect the system put in roughly the amount of gas needed, initially, but the amount continued to rise.  Fusion occurred in the short period during which the right density profile existed.  A successful machine will need to hold that condition.

It may be that it will occasionally be necessary to stop the reaction and clear the machine of junk gas, which may include fusion products in a power reactor.

Rider's final objection was dead-on right ... for HEPS, PXL-1, and WB-5.  Cusp losses of electrons in a box machine are too high.  They are irrelevant in a magrid machine.  Electrons lost out the cusps come right back in.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/07/2007 09:30 PM
Pbreed,

I believe Dr. Bussard addressed this on The Space Show on 8 May.  Run at proper density conditions, the ions have two primary zones in which collsions take place, the high fusion energy zone within the convergence radius, and the low KE zone at the outer edge.  Very little in the way of collisions takes place in between, in the volume where velocities are high but the ions are spread out radially.

The ion velocities in the central region are very high.  They don't have much time in which collisions can take place, compared to the time spent outside that region.  Yes, no-fusion collisions are more likely, but not enough will occur to cause much thermalization on any single pass.  Ions entering this zone all have about the same energy ... the non-fusion collisions are primarily elastic, and so the amount of momentum transfer in any given collision is not great.

The ions reach the outer zone near the magrid where KE is low.  They're slow, and back up.  Here they do thermalize, all to low KE.  This tends to equalize their KE.  The spend far more time here than in the central convergence zone.   Thus, on every pass, the machine will tend to "anneal out" the kinetic energy distribution acquired by core collisions.

Any ion which does happen to upscatter sufficiently on a single pass that it escapes the potential well will, in fact, be lost.  This can be minimized by making a deeper potential well (running at a higher voltage) and generating the ions at some depth into the well.  You can stop the milk from sloshing out of the bowl by using a deeper bowl.

I want to see the tests replicated and run longer, but WB6 developed an absolutely phenomenal rate of fusion for such a small IEC machine run at such a low voltage.  It is absolutely in a class by itself.  I don't think it could have achieved this rate if the theory behind it were not basically right.  Evidently, at least on the timescales on which it ran, it didn't thermalize.  I think it deserves the opportunity to demonstrate if it can be made to run longer, hopefully indefinitely, without thermalizing.

Frankly, I never trust complex system calculations without experimental verification.  Time to get in the lab and test it!
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/07/2007 09:35 PM
I am going to be in Chicago for the next three days for #2 son's graduation from college and will be unable to pitch in until I get back.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/07/2007 09:37 PM
Wiki on elastic collisions.

http://en.wikipedia.org/wiki/Momentum

From that some one ought to be able to do the math.
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 06/07/2007 10:17 PM
OK, how about this for a Members Project pitch:

For over a decade, Dr. Robert Bussard and his research team have been working on a shoestring budget on a truly remarkable technology: an unusual approach to fusion that can produce abundant clean energy.  This is not cold fusion; it's a variation of standard "inertial electrostatic fusion" (IEF) which is in common use today as a neutron source.  But IEF fusion can never produce more energy than it consumes; Bussard's "polywell" approach solves that problem, neatly side-stepping the technical difficulties which prevent IEF from being a power source.  Dr. Bussard is a well-known physicist, and one of the fathers of American fusion research.  He's worked out the theory behind polywell fusion, and supported it with early small-scale prototypes.  Based on this theory, he believes that we could have fusion power plants producing cheap power, with no radioactive waste products or carbon emissions, within a decade.  But to continue this important work, he needs more funding; broad budget cutbacks forced him to close his lab just as they were collecting their most impressive results.  He needs between $2M and $5M to rebuild the last prototype, with improvements, and collect enough data to demonstrate convincingly that his theory is correct.  If he's right, this technology will end our dependence on fossil fuels, provide a significant boost to the world economy, and end wars over oil.  The biggest global problems we're facing right now are energy production, climate change, and fighting over dwindling fossil fuels — this project has the potential to solve them all.  Doesn't it deserve a chance to be proven?
Title: Re: Fusion with space related aspects thread
Post by: pbreed on 06/07/2007 10:31 PM
Tom,
 Thanks for the detailed reply. I agree that one experiment is worth 10000 view graphs. I hope that all of this works out it would be a huge win for the planet.

I agree with everything you say about the slow ions thermalizing,
 but I have two nits to pick....

>The ion velocities in the central region are very high. They don't have much
>time in which collisions can take place, compared to the time spent outside that
>region. Yes, no-fusion  collisions are more likely, but not enough will occur to
>cause much thermalization on any single pass.

I think this ratio of near misses to actual fusion in the central high speed zone
is the key parameter that says this works or it does not. My inept read of the Rider paper said that this ratio was the key to his thermalization argument.

>I want to see the tests replicated and run longer, but WB6 developed an
>absolutely phenomenal rate of fusion for such a small IEC machine run at
>such a low voltage.

Wasn't this rate of fusion determined by catching just 3 neutrons?
A number of alternative explanations for just three neutrons could be crafted.
Extraordinary claims require extraordinary proof....

Please don't take my comments to be negative, but I believe that the steel of truth
needs to be sharpened against the stone of skepticism.


Paul







Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/07/2007 10:55 PM
Joe,
I agree with your summary text. I´d just add a couple of things.First a web link , it give more strength to the proposal and let the reviewers  go deeper inside if they need more info. (for example Wikipedia http://en.wikipedia.org/wiki/Polywell ). Second I´d remark the experimental record of WB6, 1E9 neutrons/sec at such a low voltage (10 KV). A world record consequence of new concepts in the reactor . And also the prize of Outstanding Technology of the Year 2006 , awarded by the International Academy of Science ( http://www.science.edu/TechoftheYear/TechoftheYear.htm )

Go ahead Joe!!
Title: Re: Fusion with space related aspects thread
Post by: jstrout on 06/07/2007 11:02 PM
A link is a good idea, but it might be better to put it in the comments than in the pitch.  (Each entry is followed by a comments section, like a blog.)  Also, we might want to produce a better introductory/support page than the Wikipedia entry.

The record-smashing performance of WB6 probably is worth a mention.  I'm concerned that the blurb is too long already, but we can try to work it in.

I'm not sure the prize is worth mentioning, though — anybody who looks into it is going to discovery that it's not from the real International Academy of Science, but the fake one, and in my view that sort of taints the whole thing with the air of fakery.  Best to not mention it, I think.

— Joe
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/07/2007 11:10 PM
Quote
pbreed - 7/6/2007  6:31 PM
I think this ratio of near misses to actual fusion in the central high speed zone
is the key parameter that says this works or it does not. My inept read of the Rider paper said that this ratio was the key to his thermalization argument.

Paul,

in 1995 the center of potential well formation was probably a small narrow spike on a chart. Now its a broad plateau

Photo Sharing and Video Hosting at Photobucket

To me that means more fusion at the center of the device, because those ratios are changed to be more favorable for fusion.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/07/2007 11:27 PM
Paul,

Indeed.  Nobody is more aware of the need for better data than Dr. Bussard.

Imagine, he ran four tests, technically after the lab was supposed to close down, and each one produced only a few counts.  With the data reduction not done for another month, it would not seem like much to get excited about.  Not until he figured out what fusion rate must be behind these counts did he realize what they'd done.

It is not spelled out in the Valencia report, but the four test were acutally done at increasingly severe drive conditions (the fifth evidently crossed the line and burned out a coil).  The neutron production rate increases with the four runs, at least as well as can be determined by the weak statistics.  This, too, suggests the effect is real.

I'm not sure if he used the counters I set up, as I set them up, but the ones I set up were shielded so they would not count stray arcs.  VERY effectively.  I'd consequently gotten the background rate down to a few counts per minute.  If he used the same setup, a few counts in under a millisecond, on several tests in a row, is definitely way above background.  

But that does not alter the fact that the counting statistics suck.  The precision of the fusion rate does not even rate a full digit!  But it does rate a little better than order of magnitude.

I want to see the WB7/8 tests done ... I want better data, and I want backup proof that fusion is occuring.

The amateurs on fusor.net have been using neutron bubble dosimeters to count neutrons.  While these do not give the critical timing information the electronic counters produce, they're incontrovertable proof that fast neutrons were produced in the test.  Neutron activation of indium can also be used ... it produces a characteristic and rapid decay curve that would persist after the test.

I want to see it run long enough that the ion lifetime is effectively indefinite.  Some milliseconds would probably do, some seconds would be more satisfying.  The longer it can run steadily, the more we'll know who is right, Bussard and Krall, or Rider.

If I had $200M, I'd bet it on Bussard and Krall.  But that's based on my personal level of trust of the people involved, and I expect healthy skepticism from the rest of you.

By the way, if you have access to Rider's 1994 Master's Thesis, be sure you read the last line of the Acknowledgments.  Intriguing wording there regarding ONR.  Politics between someone in ONR and NAVSEA was why Dr. Bussard was told to stay quiet for 11 years.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/07/2007 11:35 PM
Roger,

That central spike is the "virtual anode" produced by ion convergence.  That one is rather schematic.  

Give credit where credit is due ... I believe that picture was produced by Mark Duncan at Askmar.com.  Mark has been working like a dog producing improved color graphics of Dr. Bussard's figures.  What he has done with the space transportation papers is stunning.  I think he now has three of the four posted.  Those papers are why this is so exciting to the NASASpaceFlight website.

For any newbies ... check out

http://www.askmar.com/Fusion.html



Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/08/2007 12:20 AM
On www.emc2fusion.org I have seen that a new patent had been filed in September 2006 by RW Bussard et al. ( "On optimal engineering designs and constraints for net fusion power production" )  Does anyone know what this is related? Has been already granted? What are the constrains? Are the engineering topics solved? It would be great but I think there are a lot of details to optimize.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/08/2007 12:40 AM
I have not seen that yet, and my usual search engines are not turning it up.  He told me he had several patents for the device in the works, but it will probably take a couple of years to process them.

Do you have a reference or website?
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 06/08/2007 04:30 PM
I have seen a lot of talk about one of the problems with WB-6 being the control of introducing
ions of, in that case deuterium into the system.

I'm not sure what the form of the deuterium injection consisted of.  It sounds like a pipe containing the deuterium with a valve and nozzle at the end of it that sprayed the deuterium into the chamber.  Control was by opening and closing the valve.  This valve and nozzle would have been mounted to one of the magnet coils?

Question would it be possible to have the deuterium injected from a distance.  Essentially an ion accelerator with most of it's mass outside the vacuum chamber.  Deuterium would be ionized and acclerated in a controlled fashion.  Perhaps pulses of deuterium would be introduced into the chamber.

Does this idea have any merit?
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/08/2007 06:03 PM
The puff gas valve and reservoir would have been outside the system.  I suspect they had to float at high voltage.  Some sort of tube would then introduce the gas into the system.  There are all sorts of issues regarding conductance, transit delays, valve opening time (and this particular valve, once opened, could not be closed!), reservoir volume, etc, all of which affect how responsive this system could be.  Millisecond response times would be a challenge to achieve, and this may be too slow to control the machine as well as desired.

On a larger scale, I think it will be possible to build ion sources in the magrid interior faces which use something like control grids to regulate ion introduction.  Such a scheme can probably regulate ions with something well less than microsecond response times.

I compare the WB6 fuel delivery system to running an early internal combustion lab test engine using an eyedropper to introduce fuel to the air intake.  It is sufficient to demonstrate that the engine can fire, but a successful engine requires a carburetor or fuel injection.  The problems should be solveable.  

I doubt it will be possible to inject ions from the outside.  First, the magrid is an anode, not a cathode, so it will repel the ions.  To get the ions past it, they need excess kinetic energy.  That would mean they would retain sufficient kinetic energy to escape after their first pass.  The goal is to generate ions at low kinetic energy inside the volume enclosed by the magrid, so that they gain only the energy presented by the potential well, and don't have excess energy that allows them to escape.  This is why I kept bugging FogerRox to not illustrate the ions coming in from outside the magrid on his splendid animation.

Ionizing the gas near the magrid should not be a big problem.  Any low-energy electrons released by ionization will tend to stay in the vicinity ... they have no KE to allow them to move away from the magrid, but should be very effectively trapped on their B-field lines.  Thus, the ionization zone should have plenty of electrons available for ionization.  A small dose of microwaves at the appropriate frequency to promote ECR should turn the area into a highly effective ionization zone, should any additional energy be needed.   The conditions just inside the magrid are very good for inducing ionization.

I actually found it remarkable that WB6 ran as well as it did with such a simple system.  I have assumed all along that the fairly tight parameter space in which the models say this reactor scheme will operate was going to be a tough nut to crack from a control standpoint.  In fact, the reactor seems to naturally get into that parameter space fairly easily.  

I'm going to try to find some time this weekend to write up a short article on this whole internal combustion engine analogy.  I've seen the parallels for a very long time now.  I think it very nicely describes the present state of the technology, and also some of the mistaken impressions people initially have about this method of producing fusion.  My assessment is that WB6 compares to an imaginary early lab-bench engine that has been "successfully" run four times, each time firing several times.  On the fifth run, it cracked a piston.  A witness says that it looks like a very noisy and silly way of wasting perfectly good alcohol.  The inventor knows he's got the future of transportation before him, if he can just make a carburetor, add cooling and lubrication, and cast better pistons.
Title: Re: Fusion with space related aspects thread
Post by: BarryKirk on 06/08/2007 09:18 PM
What about a system that

1) ionized the deuterium
2) acclerated a controlled amount of D in a pulse with a precisely controlled quantity and velocity.
3) deionized the D

The neutral D would head into the MaGrid area at a predetermined velocity.  When it reaches the inside of the MaGrid, it would be reionized by the high energy electrons in that area.

That's a crude description of what I have in mind, but I have no idea if this is an idea of merit.

What I'm trying to acheive is to maximize the space available for the equipment that introduces the ions into the system and yet minimize the footprint of that equipment near the MaGrid.
Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/08/2007 09:39 PM
I don´t know anything else about the new patent. The only reference I have found is in the file:  http://www.emc2fusion.org/QuikHstryOfPolyPgm0407.pdf
The old patents are: (you can search them through Google Patent and download as PDF file )
# U.S. Patent #4,826,646: "Method and apparatus for controlling charged particles" (granted May 2, 1989).
# U.S. Patent #5,160,695: "Method and apparatus for creating and controlling a nuclear fusion reaction" (granted Nov. 3, 1992)
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/08/2007 09:52 PM
I think it is easier just to pipe neutral D2 into the magrid via a tube that also carries the high voltage to the magrid surface.

Once there, it becomes a question of the best way to ionize it.  For the small machines, directing neutral gas in at low pressure will typically cause a "molecular beam" to form.  Density is so low that molecule/molecule collisions are rare, so neutral gas tends to move in a straight line.  If that line is across a magrid face, that's best.  Magnetic field strength is high there, and if you take measures to be sure there are some relatively low energy (maybe 100 eV or so) electrons present, they'll ionize the neutrals, right where you want them.  Electrons in that environment (high B field) should be buzzing in tight circles around the flux "lines" and not going anywhere.  You can have quite a population of them available to ionize neutrals.

My fantasy system, for larger machines, would be to set a waveguide inside the magrid face.  Inject neutral gas at low pressure in one end, and pump out the other end.  The molecular beam travels down the waveguide and very few neutrals escape.  

If you know the magnetic field strength in the waveguide, you can inject microwaves at the corresponding ECR frequency (example, 2.45 GHz at 875 gauss).  That will turn the inside of the waveguide into pure hell for neutrals ... ionization should be nearly total.  Then use slightly negative extractor grids to pull the ions out holes in the waveguide.  Such an ion source should produce a minimum of neutrals and very highly controllable ion injection (by manipulating the extractor grids), right at the magrid face.

The problem with that scheme for WB6 is the magnetic field strength was low (around 900-1000 gauss) so the required waveguide is about the cross section of 2x4 dimension lumber ... bigger than the magnet.  At higher fields, the waveguide would be smaller.  This system favors big magnets with high field strength.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/08/2007 10:44 PM
Tom,

I think the piston engine analogy is excellent.

 Having done some work with small piston engines, I got it right away. BTW, years ago, I had a lawn mower that wouldn't start. Step one, do I have spark? Do I have gas? One can dribble gas into the carb throat, then pull the pull starter. That dribble of gas should be enough to run the engine for a few seconds.

To me that does sound familiar....
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/09/2007 01:05 AM
FogerRox,

A balky old 3-HP Tecumseh taught me that trick.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/09/2007 09:33 AM
The idea of funding via the Members Project has definite potential.  Assuming that a decent writeup can be decided upon, the key is to generate the votes.  I can't think of anything that can generate more traffic than Slashdot ( http://www.slashdot.org ) and Digg ( http://www.digg.com ).  If you can get the fusion funding possibility mentioned on both of these sites, you can generate potentially millions of votes.  I can't think of any other proposal that would get more attention from the tech community than this.  

From his past comments, it seems that Dr. Bussard really would like to go the charitable donation route.   Wouldn't it be great if the money could all be generated by a groundswell of support for the fusion idea via the Members Project?  This could be the quickest and easiest way to get him the money he needs.

Also, I was not a "member" until I recently read about their "Blus Cash" card.  It actually pays you unlimited 5% back on "everyday purchases" like gas and groceries, once you reach a $6500 transaction total in a given year.  It pays 1.5% on other purchases.  So, if you aren't a member yet, you might consider signing up.  It took me about 10 minutes, and it was approved online in only about 30 seconds.  And no, I don't work for American Express.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/09/2007 03:11 PM
I like the idea, too.  Alas, I'm not yet an American Express cardholder.  This is enough to make me consider it.  But getting a card takes some time and if somebody who is a cardholder can make this happen now, that would be better.  Tony Rusi is looking for somebody.

All of us poor folks seem to use Visa.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/09/2007 07:32 PM
Tom,

My friend Pat has an American Express card.

Also I think I have a light weight vacuum chamber figured out. Just turn the Bigelow module inside out! Make a carbon-fiber/nonburnite I-beam skeleton frame, cover it with a pressure restraint layer of vectran, and THEN put the thin atmospheric barrier on the outside!
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/09/2007 10:59 PM
If everyone can agree on the text to be posted, I am more than willing to join the Member's Project and post the idea.

I can also submit an article about it to Slashdot.  I've had a few items posted there, so I have a decent idea of how to write things up so that they are interesting to the moderators.

As for Digg, I don't have much experience about getting a post promoted to the front page there.


Chris
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/10/2007 01:56 AM
Tony,

Just remember that Dog and Pony 1, the fusor that started the amateur fusion movement, was made out of a $99 plastic dessicator.  It lasted about 3 weeks before it imploded, and would never have made fusion.  I still have a piece of it out in the garage.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/10/2007 02:23 AM
Well, I like the wording jstrout posted on page 61 (#144216).
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/10/2007 04:21 AM
I did a little more research and came up with the following from http://www.csrwire.com/News/8536.html

-------------
For every Cardmember that registers, regardless of whether they come up with a project idea or just add their input on project ideas already submitted, American Express will contribute $1 toward the winning idea. The more Cardmembers registered, the more dollars available. American Express will commit at least $1 million and up to $5 million for the winning idea.

Once the project idea submission and rating phase closes, starting June 18th American Express will work with a special Advisory Panel to review the top-rated projects and narrow the submissions to the top 50 ideas.

"In addition to our community of Cardmembers, we have enlisted a group of well-known and respected leaders across a number of fields to help us identify the ideas that are the most innovative, achievable and have a broad, positive impact on the world around us," added Linville.

Advisory Panelists include:

    * Geoff Canada – President and CEO of the Harlem Children’s Zone

    * Ellen DeGeneres – Comedian and Talk Show Host

    * Dr. Jane Goodall – Founder of the Jane Goodall Institute and UN Messenger of Peace

    * Rosabeth Moss Kanter – Harvard Business School Professor

    * Dr. Michael Lomax – President and CEO, United Negro College Fund

    * Wynton Marsalis – Artistic Director, Jazz at Lincoln Center

    * Gabrielle Reece – Professional Volleyball Player and Sports/Fitness Expert

The top 50 ideas will be announced on July 3rd and Cardmembers can then log-on and cast their vote for their favorite idea. Based on popular vote, the top 50 ideas will be narrowed to the top 25 ideas and then the top five, with the final winning idea announced on August 7th.
------------

It seems that the first hurdle to overcome is to convince a mostly non-technical panel that giving $5M to Dr. Bussard to study fusion is a good idea.  Given the audience, this has to be much more of a "sell the sizzle, not the steak" kind of proposal.  Some of these folks might not even know what fusion is.  The proposal needs to appeal to gut instincts of the panelists.  I think we should also push the fact that Dr. Bussard wants to develop the technolgy so that it is free to all developers, even though he could probably make a ton of money on it.

In addition to the text of the proposal, I think that links would be especially useful.  These need to be non-technical links.  Does anyone know how to take the part of the Google talk that discusses the impact of abundant cheap energy on the world and put it into a separate video that could be posted to YouTube?  I'm sure there are many other ways to sway a non-technical crowd, if we all think about it for a while.  We've only got a week to come up with something.

I'm already signed up at the Members Project, so I can post the proposal when it is complete.

No matter what, even if the project makes it only into the top 50/25/5, it will generate a lot more publicity that might open up more funding possibilities.

If and when the project makes it past the panelists, then is the time that the online drive to get out the vote should commence.  Even before that, peole can vote for individual proposals.  Presumably the panelists will look at the number an value of the ratings for the inividual projects.

Chris
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/10/2007 04:48 AM
I'd be happy to collaborate with any and all to come up with the final proposal.  You can contact me by reconstructing my email address from the initials from my user name followed by "ohnson" followed by "11"  at the comcast period net domain.

Chris

Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/10/2007 07:38 AM
Chris,

Thanks for picking up the ball and running with this American Express card thing!

How much does it cost to get an American Express card anyway?

I actually wish someone would post the last half hour of Bussard's Google talk on you-tube or something with a note for non technical people to watch this 30 minutes this first! I was very skeptical after the first hour. It is too complicated a subject to explain 11 years of cutting edge research in a hour. But then he comes out and explains how to literally save the world in 30 minutes! I was blown away. It's not about money for Doc, it's about saving the world. (And getting to Mars in a few weeks.)

Non-tech people will get the saving the world part.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/10/2007 01:35 PM
I have been doing some thinking about WB7 and 8.

At least one of those machines preferably WB7 should be capable of continuous operation - an hour at least.

I understand the control issues to some extent. I know they are harder in a small machine. All the better to prove we can solve them at that level.

I think from an unsophisticated investor point of view continuous operation is very important to give the confidence to go forward. In addition laser diagnostics are another essential element. Microwaves are good. However you can "see" lasers.

Just my 2 cents.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/10/2007 01:36 PM
Tony

The "Blue" line of Amex cards are free and easy to apply for.  I only recently got one, and it took all of about 20 minutes from starting to look for the online signup page to getting approved.

If you Google "american express blue cash", the top link is to the page which explains the various Amex Blue cards.  The Blue Cash is the one that I got, since it gives you a discount on purchases.

Amex is of course running the program in order to get more people to sign up for their cards and to  get more brand awareness, but as long as it benefits something worthwhile, that really doesn't bother me.  In fact, I think it enhances their reputation.

As for the proposal, I was considering of something along the lines of "On November 9, 2006 in an auditorium at Google Headquarters.  Dr. Robert W. Bussard, a noted American Physicist, gave a talk that has the potential to change the world as we know it.  He described a non-polluting, low cost, nearly limtless source of energy ..."

Basically something that tries to really grab your attention at the beginning.  It has to make you want to read more.  Someone is going to be plodding through tens of thousands of proposals, and it has to stand out from the pack.  No one else is going to start out with a talk at the Googleplex (with a link to the video), it really should make it stand out.

Any thoughts on this as an initial strategy?

Chris
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/10/2007 09:46 PM
Chris,

I am sure anything you do will be fine, time is of the essence, just as long as it includes something about the virtual end of air pollution in the next century. In the immortal words of "the wolf" (Harvey Keitel) in the movie "Pulp Fiction", just give it a good "once over". And get it out there. I personally am skeptical about global warming. I think it is more correctly called global climate change. But I know kids are dying everywhere because of global air pollution in general. No one is going to argue with that.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/11/2007 03:12 AM
I did a little Googling and figured out how to edit Dr. Bussard's Google talk down to a managable 3:14 that shows little about the technology, but much about the effect that it can have on our world.

This is something that I think can grab the attention of the Amex reviewers.  Take a look and tell me what you think.

http://video.google.com/videoplay?docid=8301617273665558256

Chris
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 03:28 AM
Tony,

Indeed.  Global warming is a hot-button with people on one side sure the sky is falling and on the other side either sure it is a hoax or thinking it may change their weather for the better, and unwilling to give up their SUV to benefit polar bears.

p-B11 fusion would certainly be an elegant fix for the problem, but people highly concerned about global warming will latch onto that quickly, and those unconcerned about global warming can find plenty of other good reasons to like it.

Once we have it, presuming it does work, we'll have the tool to address global warming that nobody has been offering.  I do believe we've been changing our climate (for about 10,000 years, in fact).  I also believe we won't conserve our way out of it.  We need a better energy solution.

Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/11/2007 04:07 AM
I believe we are headed for a cold spell. Electricity cheaper than natural gas works for me.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/11/2007 05:39 AM
Tony and all,

How does this sound:

On November 9, 2006 in a Google "Tech Talk",  noted American Physicist Dr. Robert W. Bussard  described a truly remarkable technology with the potential to provide a non-polluting, low cost, nearly limitless supply of energy.    His proposed fusion process “converts hydrogen and boron directly into electricity, producing helium as the only waste product.”  This is not "cold fusion", it is a new practical method of hot fusion, similar to the process that powers the sun.    A 3 minute collection of excerpts from the 90 minute Google presentation explaining the impact of low cost energy can be viewed at http://video.google.com/videoplay?docid=8301617273665558256 .

Dr. Bussard's process has the following benefits:

- Very Low Cost Electricity Generation
- A Cheap Abundant Source of Fuel
- No Air Pollution
- No Acid Rain
- No Greenhouse Gas Emissions
- No Toxic Waste Products

Due to budget cuts associated with the costs of the war in Iraq, the DoD contract supporting the development of the technology was cancelled.    Dr. Bussard only recently was allowed to publish the results of his 12 years of research.    The final tests before the project was shut down produced a world record of 1 billion reactions per second.  

Ever since the Google talk appeared online, the net has been buzzing with discussion of his technology and how to get the remainder of his research funded. He estimates that between 2 and 5 million dollars and one to two years are required to perform extensive testing to verify that the technology behaves as expected.    The results will then be presented to a panel of experts to prove that it is a viable solution to the world's energy problems.

Dr. Bussard is exploring various funding possibilities, but seems to like the idea of funding further testing through a non-profit organization.    He has founded EMC2 Fusion Development Corporation (see http://www.emc2fusion.org/ ) for this purpose.

This Member's Project proposal was prepared by a group of supporters who believe that practical fusion technology has the potential to change the world as we know it.    It can benefit ALL of the inhabitants of out planet.  We are just trying to do our part to make the world a better place.    This proposal deserves support because solving the world's energy problems solves many other problems as well.

The complete, highly-technical Google talk is available at http://video.google.com/videoplay?docid=1996321846673788606 .
A discussion of the talk can be found at http://www.askmar.com/ConferenceNotes/Should%20Google%20Go%20Nuclear.pdf .
A description of Bussard's "Polywell Fusion" concept is at http://en.wikipedia.org/wiki/Polywell .
A comprehensive set of links to information about Dr. Bussard's work is available at http://www.strout.net/info/science/polywell/index.html .
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/11/2007 05:42 AM
Chris, nice.

http://video.google.com/videoplay?docid=8301617273665558256
Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/11/2007 02:05 PM
Really nice Cris!! Perfect. I´d only add a short sentence about the world record achieved of 1E9 neutrons/sec (at 10 KV) to give a short technical data about the Polywell performance. Just to avoid reviewers to be confused of this highly technical fusion research from those of cold fusion. They shouldn´t have any chance of confusing Polywell ...  What about a link to Wikipedia-Polywell?
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/11/2007 02:37 PM
Jose,

I updated the origial post with your suggestions.  See what you think

Chris
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 02:40 PM
Me like!

Thanks!
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/11/2007 03:38 PM
crj,

Excellent!

I have posted it in the usual places.

I have some ideas of my own on how it should be cut. What tools did you use?

Simon

Title: Re: Fusion with space related aspects thread
Post by: crj on 06/11/2007 04:07 PM
I made the editing decisions based on minimizing the technical, so I'm sure there are many more possibilities.

I used VirtualDub ( http://virtualdub.sourceforge.net/ ) which is free.  The files that you donwload from Google Video (at least this one) are in AVI format, but with DivX compression, so I downloaded the DivX player ( http://www.divx.com/divx/windows/download/ ) to make sure that I had the DivX codec.  Once I did that, I could play the download file locally.

The editing is just a matter of opening up the video file in VirtualDub.  It allows you to cut and paste sections on a frame boundaries and then write out the result.  It's a little cumbersome getting the exact right cut points, but that could be just because I don't know the easy way to jog backwards and forwards in the file.  Make sure that you set the compression (under to Tools menu) before writing out the file, or you get about a 100X bigger file.
Title: Re: Fusion with space related aspects thread
Post by: FogerRox on 06/11/2007 06:15 PM
I am in way over my head, I found some naysayers

http://www.physicsforums.com/showthread.php?p=1354139#post1354139
Title: Re: Fusion with space related aspects thread
Post by: pbelter on 06/11/2007 07:59 PM
Good work Chris!

I was just thinking if you could consider incorporating some of Tom's slides regarding the cost of the off world colonies. Bussard alsomentioned in his presentation that it would take 76 days to fly to Saturn, this could go as backgorund.

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 08:23 PM
Roger,

A bit over my head, too, for now.  I've never really understood the bremsstrahlung objection.  Evidently, the presumption by some physicists is that "hot" electrons will produce it.  I'm not clear why that has to be.  The radiation presumably is caused by Coulomb braking action.  My understanding is that virtual anode height control is the key to controlling it.

These guys seem to think the electrons should be eliminated, resulting an a profoundly non-neutral plasma ... very positively charged, and so there would be no reason for ions to come in in the first place, so ....

One of my old standby rules is that if there is something I ought to be able to understand and I can't understand it, I should seriously consider the possibility that the thing I'm supposed to understand is wrong.  I'm not to the point of being able to see they are wrong yet because I can't even figure out where they think the effect is coming from.  I suspect they're using a rule of thumb based on some very different enviroment, possibly pure electrons.

In fact, in electronics, for may years we have used cathode rays, especially in cathode ray tubes, electron microscopes, electron beam welders and etchers, etc.  These beams do produce x-rays when they hit high Z targets, but I'm not aware the beam itself is all that high a radiation source, in spite of electron kinetic energies in the 100's of keV.  I would expect radiation only if electrons were forced to slow rapidly by like charges.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/11/2007 08:51 PM
Quote
pbelter - 11/6/2007  3:59 PM

I was just thinking if you could consider incorporating some of Tom's slides regarding the cost of the off world colonies. Bussard alsomentioned in his presentation that it would take 76 days to fly to Saturn, this could go as backgorund.


Given the non-technical "save the earth" tone of the piece, this would probably best go in the link section at the end.

Do you have any links that I could put at the end to references to space applications of the technology?

Title: Re: Fusion with space related aspects thread
Post by: Stargazin2nite on 06/11/2007 09:04 PM
Sorry for entering this thread so late, but could anyone please point to any peer-reviewed research that demonstrates any experimental results that would suggest/support further research on this subject?  Especially research that requires $150-200M funding.  As most reputable scientists know, the hallmark of scientific validity is reproducibility of results by the greater scientific community.    

This sounds way too much like Carl Collins and the recent DARPA funded isomer-triggering fiasco that wasted millions of tax payer dollars before finally getting killed.  Better be careful with your claims or you'll find yourself a subject of one of Sharon Weinberger's next books....
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 09:44 PM
Stargazin ...

Are you offering to set up a lab to test the existing experimental results?

Reproducible results implies the willingness of other labs to build similar equipment and conduct the same or similar tests.  This happens a heck of a lot less often than you seem to believe, especially when multi-million dollar equipment is involved.  It is great when it happens.  When nobody bothers, that doesn't mean the original work was not valid, it just means it has not been validated.

For major physics efforts, there is a rather serious shortage of particle accelerators the size of a french province and tokamaks the mass of an aircraft carrier.  Replication by the greater scientific community is, in such cases, moot.  Other methods must suffice.  

I would welcome such an effort, and I know one interested party who has been looking into doing just that for the small-scale work.

http://www.fusor.net/board/view.php?site=fusor&bn=fusor_introductions&key=1180646140

In the meantime, unless some funding is obtained for a restart of the lab (the proposed $5M or less WB7/8 effort), it won't even be possible to invite peers by for a demonstration.

My claims at this point are that we should get Dr. Bussard some funding and start this line of research back up, so we get better data, implement at least peer review of the tests and results, and verify that the thing really works.

Althought the reports to the sponsor were not published due to an embargo imposed by the sponsor, EMC2 did have a review board of independent researchers in the field, who reviewed the results.  Any results produced by EMC2 Fusion Development Corp should be more public and more accessable to standard review.
Title: Re: Fusion with space related aspects thread
Post by: Stargazin2nite on 06/11/2007 09:58 PM
Tom,

Since you failed to answer my original question, where exactly are the results of Bussard's work published?  Surely claims as revolutionary as his (yours?) merit publication in PRL?  How can anyone even conceive of replicating results if they don't know the details of your experiment?

-Matt
Title: Re: Fusion with space related aspects thread
Post by: Stargazin2nite on 06/11/2007 10:12 PM
Here's the all too common recipe for pseudoscience, sound familiar?

1.  Inventor has great invention
2.  Greedy establishment scientists hate great invention (and/or inventor) and want to quash it
3.  Fearless inventor battles odds and gets money from true believers (often in the Navy for some weird reason)
4.  Years go by, millions are spent.
5.  Inventor, having not saved the world, loses funding, which he attributes to enemies subverting him.
6.  World misses out on incredible contributions of misunderstood genius.
7.  World is screwed.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 10:12 PM
Sorry, I was up there editing and you were asking for more at the same time.

Since the embargo, Dr. Bussard has just published the Valencia report you can find at Askmar.

http://www.askmar.com/ConferenceNotes/2006-9%20IAC%20Paper.pdf

There is sufficient data in the report above to enable someone else to build and operate a machine similar to WB6, and most likely produce significant fusion with it.

The Valencia report does not qualify as a proper formal "paper" suitable for peer review.  In part, that is because it lacks the detailed supporting calculations.  In academic circles in bygone days, you would expect the entire theory to be published as well as experimental results.  In this case, the research environment was not academic, but rather for a sponsor who expected returns.  In fact, more and more academic research is being conducted in a semi-private manner where the real gravy is reserved for the corporate sponsors.

We don't like it ... but the sponsors won't fork over the money if they don't end up with ownership of the product.  I suspect Dr. Bussard must have this in mind.  Any sponsor willing to privately fund this research would want ownership of the product, impossible if it has been freely published.

If that is the case, the review needs to be done by the sponsor, who would be fools to offer money without seeing and reviewing the theory in detail.

If someone like the National Science Foundation were to step forward and fund this work, then we should very clearly expect a classical public peer review.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/11/2007 10:14 PM
You offering evidence, or inuendo?

Here I am trying to be nice and you're popping off conspiracy theories and trash.

Let's restart the research, get some decent data, and see if it is right.

Title: Re: Fusion with space related aspects thread
Post by: Stargazin2nite on 06/11/2007 10:23 PM
Isn't that what the Navy spent it's money for?  What did they get for it?  Why did they stop funding the research?

I'm sorry to have offended you -- you can count me as one of those physicists who have published in peer-reviewed journals and respect the scientific process.  Bussard is asking for money (which he already received from the Navy) and seems not to have produced enough results to justify getting more.  Perhaps is ARPA-E gets created this might be a suitable high-risk, high-payoff venture?
Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/11/2007 10:25 PM
I understand that people may have doubts . It´s normal. I have doubts, you have doubts... The whole history seem to be extracted from a movie ( during last months they solved the problems.... but they have no more economical support). but what I can´t understand is why people are so negative . EMC2 have been working for more than 14 years in this reactor under the DoD protection. 14 years is a long time!!!. I think you can not cheat the DoD for 14 years, something important must be behind . They have been improving their results with every new design (WB1, WB2 ....until WB6). Finally due to budget cuts for Iraq War they were not renewed as DoD researchers. We must be respectful in judging in 10 minutes what they have been doing during this long period of publishing embargo.

I think EMC2 deserves to carry on with the research. It´s true that they haven´t been per reviewed yet (It´s an important  thing to do ) but they have got outstanding results of DD fusion at only 10 KV in concordance with the calculations. They are taking a lot of risk since they just are asking for an initial budget of 2-5 M$ for 1-2 years. And later being reviewed by a group of fusion experts. If everything goes well in this first stage, EMC2 will continue with a bigger reactor. If they weren´t so confident (and enthusiastic) they wouldn´t have taken this risk. 2-5 M$ is a cheap amount of money if they achieve break-even conditions. The ratio "(expectations/budget)" is clearly high enough to justify the project.  Let´s give a chance. Let´s be optimistic. Only enthusiastic and optimistic people can change the world.

"Years wrinkle the skin, but to give up enthusiasm wrinkles the soul" (Samuel Ullman in 'Youth')

Title: Re: Fusion with space related aspects thread
Post by: Stargazin2nite on 06/11/2007 11:22 PM
Quote
Tom Ligon - 11/6/2007  5:14 PM

You offering evidence, or inuendo?

Here I am trying to be nice and you're popping off conspiracy theories and trash.

Let's restart the research, get some decent data, and see if it is right.


Tom, the suspicion of DOE conspiracy theories, quotes that "only about 5 people in the world understand this", etc. come from Bussard himself!  Read the text of his Google speech (post #88257 on this thread by josh_simonson on 11/30/2006, 2:49pm).

Extraordinary claims require extraordinary proof, and this research provides zero.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/12/2007 12:31 AM
As has already been pointed out, skepticism is OK.  Healthy, in fact.  Too many fusion claims have been made in the past.

As for the timing ... actually, the WB6 runs were made a few days after the lab was supposed to have been shut down.  Knowing the short time left, and having realized the flaw in the earlier designs, they were scrambling like mad those last few months to get the thing built and the preliminary tests run (WB6 was run to test electron confinment quite a bit before the fusion attempts).  In fact, they evidently cut some corners in the process, because the device was not robust, and did not last long at fusion conditions.  So it was not all coincidence.

And the evidence WB6 produced, only a few neutron counts, is obviously ... should I say disappointing, or thin?  Yeah, thin.  Not even a whole digit of statistical significance.  But I consider it sufficiently good to warrant continuation of the approach.

As far as conspiracy theories in the DOE go, the major one Dr. Bussard has been known to state is that he, Robert Hirsch, and Alvin Trivelpiece are the people who designed the present fusion program, and Dr. Bussard claims they knew it was a fraud when they did it.  I'm not helping his credibility, am I?   He really is not paranoid about the DOE, he simply thinks they're so invested in an idea he helped set up hoping it would raise sufficient money to find something that would actually work, that they can't acknowledge any other way.  What Bussard et. al. had in mind was trying to improve Hirsh's fusor.

Regarding the number of people who fully understand the device, that's probably just about right.  A few more partly understand it.  But that's not to say the device is so mysterious it defies understanding.  Dr. Bussard's characterization of the level of understanding necessary is several semesters of graduate level physics.  How many semesters would you say it would take to teach someone with a general physics background, how, in detail, a tokamak works?

IEF is a radical departure from conventional "thermo" nuclear approaches.  While it is clearly hot fusion, it is non-Maxwellian.  If you try to apply tokamak thinking to it (at least the shortcut assumptions ... neither machine can violate the underlying physics), you will probably fail to understand how it works.  It is necessary to un-learn thermal approaches, and learn how vacuum tubes work. This thing marries magnetic confinement of electrons with spherical solutions to Poisson's equations working simultaneously for dynamic populations of electrons and ions, diamagnetic behavior of the electrons, formation of a virtual anode within a virtual cathode, and all sorts of other effects not seen in other fusion approaches.  The closest thing to IEF is the Hirsch Farnsworth fusor, which lacks the magnetic fields and substitutes an electrostatic grid for the dynamic electron behavior.

Nobody I know has grasped how this works on one reading of the Valencia report.  A good plasma physicist with an open mind might start to in three readings.  I've hit it about seven times and I still find things I've missed.

Please, remain skeptical, but I encourage curious skepticism.  I would encourage you to become familiar with the Hirsch Farnsworth fusor, which is relatively straightforward and simple to understand.  It has been around for decades and makes a nice high school science project.  They're hopeless for net power.  The fusor is a spherical electrostatic ion accelerator, which is the effect Dr. Bussard is trying to achieve, only with sufficient efficiency to actually work.  It should be easy to understand that the fusor is, in fact, a real hot fusion machine.  The question is, if the grids are replaced by a deep electron potential well, an ideal density range (much lower than in a typical fusor) can be found, and some means of avoiding thermalization can be found, is it conceivable that such a machine might make considerably more fusion?  Even net power at some scale of size?

If you convince yourself that it is at least sufficiently possible to boost your curiosity, go back to the Valencia report and see if you can understand what WB6 was doing.










Title: Re: Fusion with space related aspects thread
Post by: TallDave on 06/12/2007 02:31 AM
Star,

As Tom says, skepticism is welcome, even essential.  You might be interested to know Polywell isn't the only IEC fusion project; something vaguely along the same lines from a Paul Allen backed startup was patented and the company's been funded for $40M.

http://news.com.com/8301-10784_3-9721240-7.html

It's a beam-beam design, but the patent makes some familiar noises:

"Preferably, plasma ions are magnetically confined in the FRC while plasma electrons are electrostatically confined in a deep energy well, created by tuning an externally applied magnetic field."

http://www.google.com/patents?id=eG0TAAAAEBAJ&dq=fusion+rostoker

There are skeptics, of course.

http://www.sciencemag.org/cgi/content/full/281/5375/307a

Maybe IEC won't pan out.  As with most major advances in technology, lot of money is going to be thrown down a lot of wrong paths before we get a working fusion reactor.  But unless one believes the neutron detection lab results are faked, wrong, or misinterpreted Polywell seems like the most promising avenue at the moment, based on the available data.

At the very least, we need to try to replicate the WB-6 results. The stakes are very high here.

Title: Re: Fusion with space related aspects thread
Post by: TallDave on 06/12/2007 02:46 AM
BTW Tom, re the SciMag discussion link, I would be interested to hear what you think of that discussion, esp. Rostoker's response and how the magnetic field enters the equations.

http://www.sciencemag.org/cgi/content/full/281/5375/307a

If you have an opinion.  I'm not sure how much this intersects with the issues you were dealing with, if at all.
Title: Re: Fusion with space related aspects thread
Post by: crj on 06/12/2007 03:29 AM
I did a litte more fine print reading at the  Amex Member's Project site and found the following requirements for the proposal:

# It cannot include any mention of any specific individual, company, organization, brands or products (although the optional Ready For Action Suggestions can include information on any company or organization which might help fulfill the Project Idea);
# It cannot contain any trademarks, tradenames, third party copyrighted material, or any material owned by any third party;
# It cannot contain any personal identification of any kind, including names, street or e-mail addresses, or phone numbers.
# It cannot contain any url addresses or website links;

This is requires some serious reworking of the propsal.  I'm not sure if it is possible to get a compelling proposal without any supporting information.

I guess I should have RTFM .

Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/12/2007 03:58 AM
I really don't know a lot about this approach.  Like Focus Fusion, who also want to burn p-B11, I greatly admire their choice in fuel.

The colliding beam approach sounds a little like another old fusion scheme called the Migma, which I also don't know much about.  I remember being intrigued by it as it was the first scheme I saw that used an accelerator approach, something I had instinctively thought ought to be tried the moment I heard that temperatures in thermonuclear devices are measured in electron volts.  Forgive me if I'm envisioning the migma and thus missing some critical operational point.

I see an advantage in a spherical approach in that non-fusion collisions will definitely outnumber fusion collisions.  No question.  With a spherical approach, it does not matter what angle the recoil occurs to ... everything is uphill against the potential well.  The question for the WB machines is, how equal is the energy transfer, will it result in thermalization, and can the thermalization be corrected.

It would seem to me, unless there is some means to recapture the scattered fuel ions and their kinetic energy, that discrete beams are at a distinct disadvangage.

But I have no doubt that colliding beams of high energy fuel ions will produce some fusion, including being able to burn fuels out of range of pure heat methods.

I do note one rather telling thing about the sciencemag.org piece -- ah, by Nevins (noted Polywell critic).  You will note that the writer talks in terms of "heat" and "heating".  This is an example of what I mean by tokamak thinking, and a shortcut that can lead to misunderstanding if you are not careful.  I have seen people make assumptions based on "conservation of energy" in which they fail to appreciate the reference frames needed in this transformation when dealing with two moving ions, and manage to totally mis-calculate the collision velocity, and also foul up their cross section calculation.  He does mention having to watch the frame of reference in converting from temperature (i.e. kinetic energy) to velocity.  The formula for fusion rate is the product of the two fuel species densities times reaction cross section times the relative velocity of the particles. n1 n2 sigma v.  Temperature occurs nowhere in this calculation.  Velocity causes fusion.  Even in a tokamak.   In accelerator-based "non-thermal" approaches, it is best to be wary of the concept of heat, and think more directly in terms of particle motion ... velocity and momentum.

So scrolling down ... yeesh, math overload.  But I pick out something I recongize.  Vlasov.  Interesting.  Rostoker is using the name of someone whose name also appears in Dr. Bussard's description of the EIXL code:  a 1.5D radially-dependent Poisson solver, static solutions for potential and density, satisfies collisionless Vlasov equation, utilizes Runge-Kutte and Newton-Kantorovitch methods, momentum conservation, Heavyside energy distribution ... virtual anode height control.  You guys all understand that, right?  Me either.  Frankly, I suspect Dr. Bussard had to have Dr. Krall explain at least half of it.  Other than Heavyside energy distribution, I don't see much pertaining to "heat".  I see Poisson and conservation of momentum ... those clearly belong in IEF methods.  The virtual anode height control is supposed to mediate bremsstrahlung losses.  

If Nevins is missing this Vlasov fellow on one method, he's missing him on both.  I never like to ignore Russian math whizzes ... they're smart.

Stargazin ... it appears we need a physicist.  Can you decode any of this?
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/12/2007 04:08 AM
crj,

The value of the proposal is in getting the info out.

Winning the contest is not a viable goal at this time, given the rules.
Title: Re: Fusion with space related aspects thread
Post by: M Simon on 06/12/2007 04:22 AM
Runge Kutte is not hard:

http://en.wikipedia.org/wiki/Runge-Kutta_methods

I'm still looking for a good reference on Newton-Kantorovitch.
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/12/2007 09:30 AM
Talldave, crj, and Tom:

Talldave:

I found another link that claims one of the researchers worked with Maglich.

http://www.thealarmclock.com/mt/archives/2007/05/nuclear_fusions.html

Crj: Just follow the rules to the letter to get it out there. Days count. Even seconds count. The contest has been going on since May 15th but I didn't even know about it till a few days ago. We have already missed almost a month. Eyeballs with a buck is what we need millions of now!

Tom:

Can you really call this a thermal machine? How hot is the spot in the center? How hot do the magnets casings get? How hot does the vacuum wall get? (under steady state operations)? Ok, it has only been run for milliseconds, Ok, what is your best guess?
Title: Re: Fusion with space related aspects thread
Post by: Tony Rusi on 06/12/2007 11:37 AM
Does plasma in a polywell exhibit fractal behavior?

http://space.newscientist.com/article/dn11935-solar-wind-becomes-fractal-when-stormy.html

Title: Re: Fusion with space related aspects thread
Post by: cuddihy on 06/12/2007 12:28 PM
Quote
M Simon - 11/6/2007  11:22 PM

Runge Kutte is not hard:

http://en.wikipedia.org/wiki/Runge-Kutta_methods

I'm still looking for a good reference on Newton-Kantorovitch.

Newton-Kantorovich is yet another method of approximating a solution to some differential equations that are otherwise unsolveable. I doubt it's worth your time to find out how to do it unless you want to use it.
Title: Re: Fusion with space related aspects thread
Post by: Tom Ligon on 06/12/2007 01:35 PM
Tony,

For every volt of accelerating potential, multiply by 11604 Kelvins.  At 10 keV, individual ions have a "temperature" of 116 million degrees, and that's near the bottom end of the fusion world.

Fusion products will typically be several MeV.

Before panicking, consider that the electrons in a cathode ray tube of an old color TV may be at twice that temperature.  In all these cases, the density of the "hot" species is fairly low.

Amateurs are building Hirsch-Farnsworth fusors which they typically operate at 40-60 keV.  The internal grids will typically run orange- to yellow-hot due to impacts from ions at full kinetic energy, and have a short life.  The walls of the chambers typically get too hot to touch comfortably, but they don't melt down.  The grids are one of the worst energy-robbers in a fusor.  Wall heating is probably largely due to fast-neutral charge exchange ... ions losing their energy to neutrals which hit the walls and are lost.  Electrons produced from the convergence zone produce an e-beam which can cause local heating of the walls.

I don't know if any sort of fractal geometry applies.  That approach would seem more appropriate for turbulent (viscous) motion than for molecular motion with long mean free paths.


Title: Re: Fusion with space related aspects thread
Post by: jlumartinez on 06/12/2007 02:20 PM
TallDave,
Note that the two Bussard´s US Patents  ( Nº  4826646 and  5160695  from 1989-1992) are explicity cited in Monkhrost and Rostoker patent ( Nº 6852942 and others, years 2005-2007)  from the Tri Alpha Energy Corp.  Maybe they are using some ideas related to pioneer Bussard´s work to get a good confinement.

Bussard   --> http://www.google.com/patents?vid=USPAT4826646
                    http://www.google.com/patents?vid=USPAT5160695

Rostoker --> http://www.google.com/patents?vid=USPAT6852942    and others...
Title: Re: Fusion with space related aspects thread
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