Nonlinear expansion and heating of a nonneutral electron plasma due to elastic collisions with background neutral gas

This paper investigates theoretically the heating and nonlinear expansion of a nonneutral electron plasma due to elastic collisions with constant collision frequency nu(en) between the plasma electrons and a background neutral gas. The model treats the electrons as a strongly magnetized fluid (omega(pe)(2)/omega(ce)(2) much less than 1) immersed in a uniform magnetic field <B-0(e)over cap (z)). The model also assumes an axisymmetric plasma column (partial derivative/partial derivative theta=0) with negligible axial variation partial derivative/partial derivative z=0), and that the process of heat conduction is sufficiently fast that the electrons have relaxed through electron-electron collisions to a quasi-equilibrium state with scalar pressure P(r,t) = n(r,t)T, and isothermal temperature T. Assuming that the electrons undergo elastic collisions with infinitely massive background gas atoms, global energy conservation is used to calculate the electron heating rate, dT(t)/dt, as the plasma column expands on a time scale tau(diff)similar to(omega(pe)(2) nu(en)/omega(ce)(2))(-1), and the electrostatic potential energy decreases. Coupled dynamical equations that describe the nonlinear evolution of the mean-square column radius r(0)(2)(t) and electron temperature T(t) are derived and solved numerically. (C) 1996 American Institute of Physics.