Rate of S2F10 production from negative corona in compressed SF6

Using a mass-spectrometer-gas-chromatograph capable of detecting S ₂F₁₀ concentrations in SF₆ down to the part in 10⁹ level, the rates of S₂F₁₀ production from DC glow-type negative point-plane corona discharges in pressurized SF₆ have been measured at different absolute gas pressures in the range of 100 to 500 kPa and at different constant discharge currents in the range 2 to 80 μA. The charge rate of production for S₂F₁₀ was observed to drop with decreasing discharge current, and the yield curves exhibited nonlinearities in the early stages of the discharge that appear to be associated with conditioning of the point electrode. The nonlinearities became more pronounced with increasing gas pressure. The results were found to be quite reproducible and suggest the possibility of using this type of corona discharge as a reliable method for preparing reference gas samples that contain predictable trace quantities of S₂F ₁₀ in SF₆