FRC + Imploding Plasma Liner Fusion for the Fusion Rocket (NIAC2)

[Stormbringer]

sorry about that i temporarily conflated it with another reactor design. late at night no sleep don'tcha know.

well, perhaps the propellant charge could be hydrogen or something like that; that won't gum up the reactor with residue. otherwise yeah you would need a rail gun or similar effect.

I am so confused as to what you are trying to do...
First of all, the MSNW fusion driven rocket uses no lasers and then their fuel is hydrogen with a lithium liner.

[Elmar Moelzer]

sorry about that i temporarily conflated it with another reactor design. late at night no sleep don'tcha know.

No worries, mate! I make plenty of mistakes myself for the same reason, or because of a lack of time. just making sure we are all talking about the same thing here.

[Elmar Moelzer]

Here is a newish video of John Slough explaining their ongoing work on power generation and the fusion driven rocket. We get to see some of their latest prototype equipment, which is really cool:
http://www.engadget.com/2013/09/12/peripheral-vision-003/

[alexterrell]

Some interesting points:

"We know how to make the plasmoids"
"We know how to propel them at the right speed"
"We've imploded shells"
"Now we need to combine the two"

and, puzzlingly:

"We hope to do that later this summer".

The article date is Sep 12th, so I guess the video was made in the summer. So when are they going to combine them and get fusion?

And if they do, are NASA and outside investors going to wade in, to profit from what would be a Nobel prize winning achievement?

[Stormbringer]

sorry to piggyback on the thread but there are a boatload of fusion progress news article on space daily today. I figure that people interested in such news articles are reading this thread. so I hope y'all will forgive the fusion spamming. you can think of it as a "plasma" instability.

http://www.spacedaily.com/reports/New_antenna_spreads_good_vibrations_in_fusion_plasma_999.html

http://www.spacedaily.com/reports/Plasma_experiment_demonstrates_admirable_self_control_999.html

http://www.spacedaily.com/reports/Lifting_fusion_power_onto_an_optimized_pedestal_999.html

http://www.spacedaily.com/reports/Monitoring_material_changes_in_the_hostile_environment_of_a_fusion_reactor_999.html

http://www.spacedaily.com/reports/Bring_a_50000_degree_plasma_into_your_living_room_999.html

http://www.spacedaily.com/reports/Hot_lithium_vapors_shield_fusion_facility_walls_999.html

http://www.spacedaily.com/reports/Fusion_foe_lends_a_helping_hand_999.html

[Elmar Moelzer]

Most of these articles are for tokamaks. Tokamaks are big and face many challeges that will make it hard to make them cost competitive with coal. Plus, they are still "30 years away". This is why I hope that alternatives like the ones proposed by MSNW LLC (the people that are also working on the fusion driven rocket), Tri Alpha, EMC2 or Lawrenceville Plasma Physics will beat them.

[alexterrell]

I agree.

The Tokomak is currently the most reliable way to make fusion, but I think is a dead end for commerical or space exploration.

Good for jobs in the south of France though.

[Clyde]

Hi there,

I have heard about this type of rocket for a while.
Maybe it is stupid, but there is sthg I do not understand.

At the moment we have not managed to produce more energy by fusion than we need to initiate the fusion.

I assume that the proposed engines also require more energy than they produce. So it means that an additional source of energy is needed, this seems to be missing from the discussion.

How much energy you need to take with you to make the engine work is an important factor, hence it would be good to know how many Joules they get out for each Joule they put in? I think for the Jet fusion reactor in the UK the best was a ratio of 50% and Iter should go beyond 100%.

What am I missing?
Thanks

[93143]

At the moment we have not managed to produce more energy by fusion than we need to initiate the fusion.

Actually...

I assume that the proposed engines also require more energy than they produce.

Bad assumption.

There are lots of ways to make fusion.  Tokamaks are the favoured candidate right now for "big science", but there are any number of smaller-scale proposals that will be much easier to develop into power plants if they work as projected, which several of them look at least moderately likely to do.

This particular method is a bit cumbersome for a power plant (it's about halfway between a tokamak and a bomb), but as a spacecraft engine it should be okay.  Based on their calculations, they hope to achieve gains as high as 200.

The whole point of this drive is that the power requirements are vastly smaller than for (say) VASIMR, which has better Isp and can vary it to optimize its thrust profile.  This is possible because of the large fusion gain.  A couple of solar panel wings of modest size, or an MHD turbine in the exhaust, would power the drive just fine.

...

I don't see why controlled net gain from fusion should be Nobel-prize-worthy, especially if it doesn't make a good power plant.  It's not a physics breakthrough any more; its elusiveness is mostly a matter of funding.  (In fact, JT-60 in Japan reached what would have been a gain of 1.25 if it had been running a D-T plasma instead of D-D.)  It'd be like Elon Musk launching a Falcon 9 first stage with a nosecap and a small dummy payload, and then getting a Nobel prize in physics for proving that SSTO is theoretically possible.

[Clyde]

At the moment we have not managed to produce more energy by fusion than we need to initiate the fusion.

Actually...

[/quote]

Thanks for pointing out the obvious ;-) Does not move the question forward much I am afraid.

I assume that the proposed engines also require more energy than they produce.

Bad assumption.

There are lots of ways to make fusion.  Tokamaks are the favoured candidate right now for "big science", but there are any number of smaller-scale proposals that will be much easier to develop into power plants if they work as projected, which several of them look at least moderately likely to do.

This particular method is a bit cumbersome for a power plant (it's about halfway between a tokamak and a bomb), but as a spacecraft engine it should be okay.  Based on their calculations, they hope to achieve gains as high as 200.

The whole point of this drive is that the power requirements are vastly smaller than for (say) VASIMR, which has better Isp and can vary it to optimize its thrust profile.  This is possible because of the large fusion gain.  A couple of solar panel wings of modest size, or an MHD turbine in the exhaust, would power the drive just fine.

So thanks for clarifying this point, you are answering that these proposals are supposed to generate more energy than they require. If that's feasible that's very interesting. Obviously it takes more than 5 minutes to judge whether they are solid on the point of view of the physics, so i won't say anything on that. At the moment even accelerator based fission reactors have not yet been demonstrated with more output than input but they are in the work in several countries. So why not fusion after all. The beam energy needs to be a bit higher, but beam energy is usually a small fraction of the energy input. (coming usually from energy losses in magnets, cooling etc if dealing with beam) . On the other hand the energy output should be larger than for fission, so does not sound impossible


 

[alexterrell]

...

I don't see why controlled net gain from fusion should be Nobel-prize-worthy, especially if it doesn't make a good power plant.  It's not a physics breakthrough any more; its elusiveness is mostly a matter of funding.  (In fact, JT-60 in Japan reached what would have been a gain of 1.25 if it had been running a D-T plasma instead of D-D.)  It'd be like Elon Musk launching a Falcon 9 first stage with a nosecap and a small dummy payload, and then getting a Nobel prize in physics for proving that SSTO is theoretically possible.

Perhaps it's not such a scientific break through.

But controlled fusion on a small scale should be a trillion dollar breakthrough, as it should be commercially viable and easily expandable, unlike the ITER design.

If Imploding Plasma Liner can work well for rocket propulsion, it could also solve the energy problem on Earth.

[93143]

The beam energy needs to be a bit higher

What beam?  They're mashing a plasmoid with a magnetized metal liner.

[Elmar Moelzer]

Perhaps it's not such a scientific break through.

But controlled fusion on a small scale should be a trillion dollar breakthrough, as it should be commercially viable and easily expandable, unlike the ITER design.

If Imploding Plasma Liner can work well for rocket propulsion, it could also solve the energy problem on Earth.

If you watch the video and visit their website, you will see that they have a better system for power generation. It also uses FRC plasmoids, but instead of imploding a metal liner on them, they have two plasmoids collide. It is is a lot less "messy" and can be repeated faster and more efficiently. The gain would be a bit lower, but it is still financially more reasonable and that is what when it comes to generation of power on earth. MSWN is one of my personal frontrunners for viable nuclear fusion.

[alexterrell]

I'm not sure whether the plasmoid collision is better or not.

The propulsion method holds out the hope of electrodynamic conversion to electricity, bypassing carnot limits.

The important thing is they have two methods up their sleeve, and I'd expect investors to be knocking their door down - at least to ask whether they can do due diligence.

If they do a demo showing decent fusion gain, it should be a big news item.

ITER will of course continue on regardless.

[Elmar Moelzer]

I'm not sure whether the plasmoid collision is better or not.

Well, they think it is because it is simpler more robust and can be easily repeated many times a second. You cant do that as easily with the propulsion system.

The propulsion method holds out the hope of electrodynamic conversion to electricity, bypassing carnot limits.

They might do that for missions to the outer planets, but for mars missions solar panels are lighter and simpler.

The important thing is they have two methods up their sleeve, and I'd expect investors to be knocking their door down - at least to ask whether they can do due diligence.

I don't know how well they are funded by private investors right now. I know that they are still looking for financing for their Helion terrestrial fusion reactor prototype. I think everyone there hopes that once they demonstrate break even with their fusion driven rocket, their other projects will find more interest as well. Another positive aspect is that all their fusion related projects share common elements (as John Slough pointed out in the video as well). So research grants for one project benefit the other.

If they do a demo showing decent fusion gain, it should be a big news item.

ITER will of course continue on regardless.

Agree on all accounts.

[Elmar Moelzer]

For those interested, John Slough will be presenting the latest results of MSNWs fusion driven rocket research at the NIAC 2014, tomorrow at 4 pm PST.
http://www.livestream.com/niac2014

[Elmar Moelzer]

There is a recording of this years NIAC presentation by MSNW here:
The presentation starts at 28 minutes in:
http://www.livestream.com/niac2014/video?clipId=pla_968e4646-c1e2-484d-8b54-bf379acb3466&utm_source=lslibrary&utm_medium=ui-thumb

Note that Anthony Pancotti did the presentation instead of John Slough.

[adrianwyard]

It's a good introduction to their plans: enabling a DRA5 type Mars mission with fast transit times on one SLS launch (~130mT). I didn't notice any substantially new information until the Q&A.

Here are a couple of things I noted. Other may have more:

+ Pulse time is every 13 seconds. Crew can probably be shielded from this by active shock absorber (with an additional energy requirement that's not factored in now?).
+ Plan is still to form the liners on demand from spools.
+ Thus far they've been focused on refining and verifying the mechanics of liner compression and magnetic characteristics.
+ They're now turning to the fusion side, notably the neutronics.
+ They do not expect to achieve breakeven, but do expect neutrons (i.e. fusion.)
+ There's a chance they will need more complex liners (than just Li) to capture the high-energy neutrons, i.e. an additional layer of Beryllium.

[Elmar Moelzer]

+ They do not expect to achieve breakeven, but do expect neutrons (i.e. fusion.)

Small correction there: They do eventually want to have a gain of 200, so 200 times more than break even, but with the NIAC2 funded experiments they wont be able to do that and they are just aiming at producing enough neutrons to proof their concept.

The addition of beryllium to the liner is a bit of a bummer. It makes things a lot more complicated. I hope that they will be bale to solve this in a (maybe different) way that wont increase system complexity and mass by too much.

[adrianwyard]

Yes, to clarify: they do not expect breakeven in the next round of NIAC testing.