Energy deposition in the cathode layer of transient high pressure glows derived from interferograms of the emanating pressure wave

Abstract

The large electric fields in the cathode sheath of high pressure glow discharges lead to localized energy deposition in the gas, which drives a gas dynamic pressure wave into the region where the transient high pressure glow is homogeneous. For a range of parameters typical for discharge pumped XeCl-lasers the gas density profiles of these waves have been measured interferometrically with high spatial resolution (20 μm). From comparisons with gas dynamic model calculations the amplitude and the spatial profile of the initial temperature distribution resulting from the energy deposition during the formation of the cathode sheath have been determined. These data can be used to verify assumptions to be made in future improvements of self consistent discharge models of the cathode sheath formation.