TallDave wrote:Were Haines and Sadowski dealing with plasma in LTE?
I'm not sure. They don't go into a lot of detail, and it is not obvious that any of the 7 references they cite will be more enlightening. They give the "self-consistent ... pressure balance" as
I believe that p is a generalized pressure tensor and does not require the assumption of a Maxwellian distribution. In some previous posts I have tried to come to grips with these issues, e.g. by calculating the electric potential that a non-neutral cusp fan would produce, but I would prefer to see this done by an expert. If you can shed some light on the physics, please do. Better yet, dig up a good review on electrostatic plugging.
For me, the bottom line of this review is Fig. 37, "Reactor scaling for a spindle cusp, with n*tau = 10^15, T = 12 keV, R = a_w = L = sqrt(pi) a for sheath thicknesses 2*(a_e*a_i)^1/2 and 2 a_i in the ring cusp." The smallest radius that meets all the constraints is
2500 m! If I assume the minor physics miracle of a sheath thickness of 2 a_e and the technologically very challenging value of 30 T for the magnetic field, while ignoring the unmanageably huge radiation flux to the wall, I still land at a radius of
50 m.
The biggest loophole I can see, slim though it is, is that electrostatic plugging is somehow possible after all.