Electron energy distribution function in He-CO radio-frequency plasmas: The role of vibrational and electronic superelastic collisions

Abstract

The role of vibrational and electronic superelastic collisions in collision‐dominated He‐CO rf bulk plasmas has been studied by solving the time‐dependent Boltzmann equation in the presence of different concentrations of vibrational [CO(v=1)] and electronic [CO(a³Π),He(³S)] states. The results, which have been obtained for a field frequency ω of π 10⁷ s⁻¹ Torr⁻¹, show that the presence of excited states is such to markedly enlarge at medium electron energies and to strongly enhance at high energies the electron energy distribution function with large consequences on the related macroscopic quantities of the electrons, particularly on the mean collision frequencies of high threshold inelastic collision processes.