Investigation on the electrode surface roughness effects on a repetitive self-breakdown gas switch

Abstract

The influence of the electrode surface roughness on the self-breakdown gas switch is investigated by physical analysis, computer simulation and experiment in this work. The Cu-W electrodes of different surface roughnesses were tested under the conditions of pulse repetitive frequency of 50 Hz, self-breakdown voltage of ~30 kV, and peak current of ~2 kA for ~93000 shots (total charge transferred was ~15 C). The coefficients of variations of the self-breakdown voltage of Cu-W 0.8, Cu-W 3.2 and Cu-W 12.5 electrodes were ~2.95%, ~1.62% and ~1.16%, respectively. With the increase of electrode roughness, the erosion area decreased continuously, indicating that the breakdown positions were more stable and the coefficient of variation of breakdown voltage decreased. The method that decreasing the coefficient of variation of the self-breakdown voltage by increasing the surface roughness of electrode greatly improves the stability of the self-breakdown switch, which is of significance to the application of the self-breakdown switch in the compact high-power pulse power devices for long time and stable operation.

Special issue on selected papers from CEPC 2021

“…1009-0630/22/070101+02$33.00 liquid meniscus formation in the ionic liquid electrospray process [8], simulation of the helicon plasma source in magnetoplasma rocket engine [9], numerical study of effect of aft-loaded magnetic field on multiple ionizations in Hall thruster [10], and the characteristics of plasma in a novel laser-assisted pulsed plasma thruster [11]. These papers reflect the latest progress in electric propulsion technology in universities, research institutes and aerospace industry departments of China.…”