Linear voltage recovery after a breakdown in a pulsed dc system

TL;DR

This study investigates how linear voltage recovery after a breakdown in pulsed dc systems affects secondary breakdowns, finding that more pulses and controlled ramping reduce breakdown rates and localize secondary events.

Contribution

It introduces an optimized linear voltage recovery method in pulsed dc systems to minimize secondary breakdowns and improve high-voltage device efficiency.

Findings

More pulses during recovery reduce secondary breakdowns.

Steeper voltage ramps localize secondary breakdowns near the end.

Peak breakdown probability occurs around 1 second after ramping, decreasing exponentially with energy input.

Abstract

Breakdowns may occur in high-voltage applications even in ultrahigh vacuum conditions. Previously, we showed that it is important to pay attention to the post-breakdown voltage recovery in order to limit the appearance of secondary breakdowns associated with the primary ones. This can improve the overall efficiency of the high-voltage device. In this study, we focus on the optimization of the linear post-breakdown voltage recovery, with the principle aim of alleviating the problem of the secondary breakdowns. We investigate voltage recovery scenarios with different starting voltages and slopes of linear voltage increase by using a pulsed dc system. We find that a higher number of pulses during the voltage recovery produces fewer secondary BDs and a lower overall breakdown rate. Lowering the number of pulses led to more dramatic voltage recovery resulting in higher breakdown rates. A steeper voltage increase rate lead to a more localized occurrence of the secondary breakdowns near the end of the voltage recovery period. It was also found that the peak BD probability is regularly observed around 1 s after the end of the ramping period and that its value decreases exponentially with the amount of energy put into the system during the ramping. The value also decays exponentially with a half-life of (1.4$\pm$0.3) ms if the voltage only increased between the voltage recovery steps.