Controlled fusion burning and current drive in a degenerate plasma

Summary form only given. In a Fermi-degenerate plasma, the rates of electron physical processes, such as collision, bremsstrahlung, inverse bremsstrahlung and Compton scattering, are much reduced due to the Fermi-Dirac statistics. Especially, ion-electron couplings (ion-electron collision and electron-ion collision) are vastly reduced. We use this fact about reduced ion-electron coupling in addressing two well-known plasma physics problems: advanced fuel burning and current drive. We show how, in a degenerate plasma, changes in the power balance for fusion make feasible regimes where aneutronic fuel can be ignited. For electron-based current drive mechanisms, the current drive efficiency is higher than n the classical prediction by more than a factor of 6 in a degenerate hydrogen plasma, mainly because the electron-electron collisions do not quickly slow down fast electrons. Moreover, electrons much faster than thermal speeds are more readily excited without exciting thermal electrons. In ion- based mechanisms of current drive, the efficiency is likewise enhanced due to the degeneracy effects, since the electron stopping power on slow ion beams is significantly reduced