COMPUTATIONAL METHODS FOR THE STUDY OF COLLISION PROCESSES IN GLOW-DISCHARGE PLASMAS

The influence of basic elementary processes in a simplified model of a n Ar plasma on the electron distribution function has been studied by computer experiment. The main aim of simulation was to build the quali tative model of plasma based on a reduced set of scattering processes. Its ability to maintain a given, e.g. Maxwellian, distribution of ele ctron energies was chosen as a criterion for correctness of the model. It was found that in the positive column of de glow discharge, in ine rt gas plasma, the minimal set of electron interactions must consist o f collisions: electron-neutral atom (elastic, excitation and ionisatio n), electron-electron and electron-positive ion. A combination of the Monte Carlo and molecular dynamics methods with some new algorithms fo r deterministic calculations (particle mesh Ewald method and Fast Mult ipole method) was adopted as a simulation technique. The Monte Carlo m ethod was found to be much more effective than even the best determini stic algorithms. However, as the Monte Carlo method has a limited accu racy only, an attempt was made to improve it. (C) 1997 Elsevier Scienc e Ltd. All rights reserved.