HIGH-ENERGY ELECTRON-BEAM DEPOSITION AND PLASMA VELOCITY DISTRIBUTION IN PARTIALLY IONIZED N-2

The electron distribution function is calculated for a plasma created when a high-current, high-energy (∼MeV) electron beam enters nitrogen gas. No spatial dependence is considered for the distribution function and the velocity is expanded in the two-term approximation. Time dependence is retained. Benchmark calculations are presented that compare code output with experimental results of electron deposition studies and swarm studies in nitrogen. Production efficiencies are given. The effect of inner-shell processes is discussed. An example illustrates the importance of the beam-induced electric field on the plasma generation and behavior. It shows that considerable ohmic energy deposition can be involved and that, consequently, production of certain species can be greatly enhanced.