- is fusion propulsion potentially easier to develop than economical fusion electric power generation?
I have a couple of questions about fusion propulsion:- which approach offers the highest T/W ratio?
- which approach the highest ISP?
- which approach is best understood at present?
If you have fusion for propulsion, it is trivial to extract power.
Are you referring to this Orion:http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29 Because this Orion uses fission, not fusion.
A concrete example of a fusion confinement scheme that would work better in space is levitated dipole fusion. It has a very simple and stable magnetic field configuration that seems to lead to stable confinement. But a fusion plant on earth would need a way to levitate the dipole, and would also need a fairly large vacuum chamber.
I'm sure the advanced nuclear physicists are going to rip apart what I'm saying but here goes..Yes, fusion great...Bussard is right a tocamac won't work, you need a spheromac or some form of electromagnetic confinement device to hold boiling hot gases in a magnetic field.I think you should have graphene (carbon) tubes with Liquid helium cooling the magnets and CO2 as a working gas for the reactor and a layer of aerogel in between the tubes so the liquid helium is contacting the rings and the CO2 is in proximity to the wiffleball.You need some hi-temp photovoltaics to absorb the EM rays and hi temp semiconductors in the corners to take the electron energy.You still need to work out how the hell to extract the waste helium from the wiffleball and exhaust it, I have no idea how you do that (assuming you are doing a DD fusion)Boron11 Helium 3.... Nitrogen I think will be the waste product.Boron11 will be harder to work with as it isn't a gas at room temperature, you have to turn it into a burning hot gas before you can even slot it into the reactor.Most of the ship's body would be heatsink just to radiate the heat away as there is no other way of losing heat in space and that fusion reactor is going to create PLENTY of heat.If you could get the reactor working, I propose a form of electromagnetic propulsion suggested by a physicist from Somerset in England whereby a neo-dymium bismuth alloy of tiny pellets are flown around a cyclotron to relatavistic speeds on board the ship and only released in the opposite direction of where you want to go.In an atmosphere the air within the cyclotron will slow down the pellets but in a vacuum you can really go fast.Momentum = Mass x Velocity. Make the mass small (efficient) make the velocity big (efficient).Keep flinging out BiNd pellets thousands of times per second and you can go anywhere you want.How do you do this? Ask the US Navy very nicely to declassify IEC fusion research and make it public.Fund it, Build it, fly it.Easy Said propulsion system will work both atmospherically and in a vaccuum because you are using inertia
On the choice of fuel, why p-B11? Isn't it even more difficult to ignite than D-He3 and delivers a smaller specific impulse? I know D-He3 isn't completely aneutronic but mostly so. So shouldn't D-He3 be the fuel of choice for spacecraft?
And on Orion, since Orion is basically the only conceivable high thrust fusion propulsion concept (delivering true "torch-ship" performance with possible multi-gee accelerations and a very high specific impulse), how can pure fusion pulse units be designed? There is ICF, where you blast fusion targets with electron beams or lasers to fuse them, but so far this has only worked using D-T or D-D fuel and the laser assembly is huge ... not a good candidate for a high thrust propulsion system. What about antimatter ignited fusion? Could pulse units be designed with an antimatter "sparkplug", or could pulse units be ignited by antiproton beams? How do you produce clean Orion pulse units (no fission?)?
There seems to be a lot of talk about Polywells here ... but as far as I understand it is far from sure whether these things would work ... it's not really a mainstream concept. If would be awesome if they would work, however.On this Winterberg design, how is the capacitor charged? What is the main power source? What would the T/W of such a craft be? I read elsewhere that he suggested to use D-T D-D combined pellets and large lasers to boost huge payloads into orbit.Could his method of D-D fusion be somehow converted into a terrestrial power plant?
EMC2 should be issuing their report on the work done with WB-8.1 in the next month or two to the Navy.