Barry Kirk wrote:Are you assuming that the ions and the electrons form a homogeneous mixture? Is there any way to set up standing waves in the reactor that would tend to layer and separate the electrons from the ions?
The standard calculation, of course, starts out with a number of assumptions, in particular that the plasma is homogeneous and the ion and electron velocity distributions are Maxwellian, and that the ion energy loss is at least as great as the classical collision loss to the electrons and the electron energy loss is at least as great as the classical bremsstrahlung loss. Within these assumptions, the fuel mix and the temperatures are allowed to vary to maximize the ratio of fusion power to bremsstrahlung power. This derivation is rigorous and not controversial.
If Rick disagrees with this result, then he must believe that one of these assumptions is not justified. I would like to hear which one. You are asking whether the assumption of quasi-neutrality might be relaxed by creating structures smaller than the Debye length. It's an ingenious idea, but I cannot see how it could be done, and if it were, I would expect plasma oscillations that would entail the electrons and ions passing through each other periodically, which presumably would result in the energy transfer you are trying to avoid. Relaxing any of the other assumptions will lead in a similar way to additional effects that could negate any benefit. That is why I would like to hear the details. Maybe Rick is forgetting to take some effect into account. It would be very exciting for me if he presented a detailed model and I could not poke any holes in it.