A self-consistent one-dimensional model of the anode region of inert gas discharges at low pressures and currents

A self-consistent one-dimensional model of the anode region of inert gas di scharges at low pressures and currents is developed on the basis of non-loc al electron kinetics in spatially inhomogeneous fields. The model is based on the kinetic equation for electrons, the momentum transfer equation for i ons and Poisson's equation. These equations are solved in the extended, non -uniform, quasi-neutral plasma disturbed by the anode and in the thin colli sional sheath of space charge. The input parameters are the discharge curre nt, neutral gas pressure and the radius of the tube. The axial profiles of the field, potential, radially-averaged densities of charged and excited pa rticles, rates of excitation and ionizations and the ion current densities are obtained from the anode to the positive column. Two different cases are modelled which correspond to the self-consistent formation of either monot onous or non-monotonous electric field profiles. These cases correspond to different mechanisms of ion production in the sheath and the quasi-neutral plasma in the anode region. Particular calculations are carried out for neo n discharges.