Nonlinear relaxation of a nonneutral electron plasma due to elastic collisions with background neutral gas

Abstract

The expansion and nonlinear relaxation of a strongly-magnetized nonneutral electron plasma due to elastic collisions with constant collision frequency ν en between the plasma electrons and a low-density background neutral gas are investigated theoretically. An important consequence of the analysis is that electron-neutral collisions ( ν en ≠ 0) cause the electron density profile to relax to a (slowly expanding) quasi-equilibrium state with identical profile shape η eq( ϱ) to that which would be produced by relaxation to thermal equilibrium by electron-electron collisions in the absence of background neutral gas ( ν en = 0).