SIMULATION OF ELECTRICAL DISCHARGES IN GASES - NONUNIFORM ELECTRIC-FIELDS

Non-equilibrium behavior of electrons and ions in gases in an electric field occurs in many situations such as in the cathode fall region of a glow discharge, asymmetrical electrodes between which the Laplacian electric field is nonuniform, in coronas and spark breakdown. This pa per reviews various methods used to describe the non-equilibrium behav ior of electrons and the degree of success obtained with these methods . Non-equilibrium effects in the cathode fall region of a discharge is treated separately. Mainly there are microscopic methods such as Mont e Carlo simulation and Boltzmann equation analysis. Alternatively macr oscopic methods such as the momentum transfer theory (or beam model) a nd memory factor model are available. Also, a hybrid fluid/Monte Carlo method is introduced as a new treatment of non-equilibrium behavior i n high pressure and rf discharges. Future possible development in thes e areas are commented upon.