Self-consistent modelling of a molecular gas discharge

Abstract

A numerical model of a gas-discharge plasma has been studied, where the reduced electric field strength E/N, the molecular concentrations in the excited states and the corresponding electron energy distribution function (EEDF) have been self-consistently calculated for a mixture of helium and a model molecular gas. In particular, the EEDF was calculated including superelastic collisions. The results have been obtained by means of an iterative procedure, which simultaneously solves the Boltzmann equation for the EEDF, the molecular balance equations for the population of molecular states, and the balance equation of the charged particles. These results for different discharge parameters were compared with those of a cold gas approximation and of a model that neglects superelastic collisions. The results were used to calculate the power transfer from the electric field to the electron system, and subsequently, to the molecular gas.