BOLTZMANN-EQUATION ANALYSIS OF SPATIOTEMPORAL ELECTRON SWARM DEVELOPMENT

A powerful and a stable numerical method is developed to solve the Bol tzmann equation of electrons moving under the action of an electric fi eld in weakly ionized gases involving space and time gradients. It is based on the classical two term development of the distribution functi on and on a strongly implicit procedure following position and energy axis and an explicit approach along the time axis. This numerical algo rithm is successfully applied to determine the spatiotemporal variatio n of the electron distribution function and the associated swarm param eters (mean energy, drift velocity, ionization and attachment coeffici ents, etc.) in the case of nonthermal electrical discharges in differe nt gases (He, Ar and O-2) under different applied electric fields and initial and boundary conditions. The transient phase, the following st eady state phase and also the electrode effects are clearly emphasized and analyzed for each gas discharge studied. (C) 1997 American Instit ute of Physics.