Influence factors and improvement scheme on the breakdown behavior of pseudospark switch

Abstract High-power pulse generators are widely used in civil and military fields. The main switch directly determines the output characteristics of the high-power pulse generators, such as the voltage front time ( t f ). Pseudospark switches (PSS) show a promising future for middle voltage, high repetitive frequency pulse power applications. However, how to further improve the breakdown behavior without reducing its advantages is a challenging task. In this paper, the influence of operating parameters (anode voltage U A and gas pressure p ) and structural parameter (number of cathode holes) on the breakdown behavior are investigated, the related mechanism are explained, and specific improvement schemes are proposed. It is found that the t f of the single channel PSS (SCPSS) decreased significantly with increasing p , but hardly varied with U A under moderate p . However, it is not a sound solution to increase the p excessively to reduce t f . Besides, increasing the number of cathode holes can obtain a shorter t f at low pressures (which implies superior repetition frequency performance). However, at 25 Pa, the jitter (which is defined as the standard deviation of t f in multiple tests) of the 2-channel PSS is larger than that of the SCPSS. And the jitter of the 4-channel and 8-channel PSS is also greater than 6 ns and 2 ns, respectively. Through experimental and simulation analyses, it can be explained as the stepwise penetration of the virtual anode and the non-simultaneous ignition of the channels. A scheme to increase the trigger energy ( ϵ ) has been adopted to improve the simultaneous ignition probability, while shortening t f and reducing jitter. After optimization, the good ignition probability of the 4-channel PSS has been improved to 82% and the jitter has been reduced to less than 1 ns at 25 Pa and 14.7 mJ.