No abstract

No abstract

No abstract

In this paper the different methods that are available to describe the kinetics of electrons in unifonn and non-uniform electric fields under stationary conditions are reviewed. The efficiency of these methods is systematically investigated. Numerical results are given for atomic and molecular gases and the impoltance of the non-equilibrium of electrons is emphasized. The first part of this study is devoted to plane-parallel geometries, the second part to wire-cylindrical geometries. In the latter case, non-equilibrium effects, in electron avalanche amplification, 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 electrons due to electric field gradients is proposed.