Fundamental processes of SF6 decomposition and oxidation in glow and corona discharges

It is known that sulfurhexafluoride (SF₆), used as an insulating gas in HV apparatus, will oxide in electrical discharges in the presence of oxygen or water vapor to form various reactive and stable by-products. In order to interpret experimental data on rates of oxidation and by product formation in discharges, meaningfully, it is necessary to apply theoretical chemical kinetics models that utilize rates for numerous gas-phase processes as functions of gas temperature and/or electric-field-to-gas-density ratio. Current knowledge about the fundamental collision processes involving electrons, ions, free radicals, and molecules needed to understand the gas-phase discharge chemistry in SF₆ is reviewed. Implications of the fundamental rate data reviewed here for recently proposed chemical-kinetics models of corona and glow-type discharges in SF₆ are discussed