Chemical Kinetic Modelling of Non-Equilibrium Ar-H2 Thermal Plasmas

Abstract

A chemical kinetic model has been constructed to predict the gas and electron temperature dependence of the neutral and ionic species composition in Ar-H2 mixtures under thermal plasma conditions. The model includes electron impact, thermal impact, ion-molecule, and recombination reactions as well as accounting for diffusion. Important metastable and excited states of species have been accounted for as well as the presence of neutral molecules, radicals, and atoms, positively and negatively charged atoms and molecular ions, and electrons. All relevant electron temperature, gas temperature and pressure terms have been included. Calculations were performed for electron and gas temperatures between 300 and 15000 K and various pressures. Under equilibrium and non-equilibrium conditions, Ar, H2, H, ArH3+, Ar+, H+, H- and electrons were found to be the dominant neutral and charged species. No significant negative ion concentrations are observed.