KINETIC DESCRIPTION OF ELECTRONS IN INHOMOGENEOUS ELECTRIC-FIELDS

In this paper the different methods that are available to describe the kinetics of electrons in uniform and non-uniform electric fields unde r stationary conditions are reviewed. The efficiency of these methods is systematically investigated. Numerical results are given for atomic and molecular gases and the importance of the non-equilibrium of elec trons is emphasized. The first part of this study is devoted to plane- parallel geometries, the second part to wire-cylindrical geometries. I n the latter case, non-equilibrium effects, in electron avalanche ampl ification, due to the space variation of the electrostatic field, are evaluated with the help of experimental determinations. A technique to take into account, in a simplified manner, the non-equilibrium of ele ctrons due to electric field gradients is proposed.