Superposition of streamer and glow discharges in single pulse mode of sliding discharge burning in Ne

Abstract

Numerical simulation of streamer development following the 1D 'classic fluid model' of ionization wave front propagation is applied to analyze the previously observed superposition of streamer- and glow-type discharges, in experiments with Ne using a single pulse sliding discharge setup at voltage amplitudes below the threshold of the spark gas breakdown. Experimental results are presented using single pulse images of spatial discharge plasma distribution between two parallel strip electrodes placed above the alumina ceramics substrate, at Ne pressures of 30 and 100 kPa and with the applied voltage rise time of 20-25 ns. A comparison of electron density values, calculated behind the wave front and estimated from the experiments, resulted in the conclusion that discharge formation in the gap begins from the development and propagation of the ionization wave. Its formation starts from the high voltage electrode at faster temporal dynamics as compared to the glow discharge, whose slower development begins from the cathode. The structure of the visual discharge plasma depends on the discharge voltage and polarity, as well as the gas pressure. In particular, at relatively low voltage the wave propagation may stop somewhere in the gap and then the rest of the gap is occupied by the glow discharge only, as was observed in positive polarity experiments at a gas pressure of 100 kPa.