Research on the triggering process of a laser-triggered vacuum switch

Zhenghao He,Yuchen Liu,Yinan Xin

doi:10.1063/5.0057541

Abstract

The laser-triggered vacuum switch (LTVS) is a type of high-voltage closing switch with broad application prospects in pulsed-power technology. Research into the triggering process of the LTVS is not only helpful to understand the triggering mechanism of the LTVS but also beneficial to the optimization of the LTVS. In this paper, the triggering process and the delay time of a LTVS with a Ti–KCl mixture target was analyzed theoretically. A numerical simulation was performed to describe the laser-target ablation process and the expansion dynamics of the initial plasma. The simulation results were compared with the experimental results. It is clear that the triggering process and delay time strongly depend on the laser intensity. As the laser intensity rises, the velocity of initial plasma increases, resulting in a shorter delay time of the LTVS. Increasing the gap voltage can also shorten the delay time.

Highlights

A laser-triggered vacuum switch (LTVS) is a type of pulsedpower closing switch that combines the technical characteristics of an electric-triggered vacuum switch with those of a laser-triggered gas switch
The triggering process of the LTVS can be divided into three stages: target evaporation, initial plasma diffusion, and anodic plasma formation processes, corresponding to the three parts of delay time td
(1) The triggering process of the LTVS can be divided into three stages: target evaporation, initial plasma diffusion, and anodic plasma formation processes

Summary

INTRODUCTION

A laser-triggered vacuum switch (LTVS) is a type of pulsedpower closing switch that combines the technical characteristics of an electric-triggered vacuum switch with those of a laser-triggered gas switch. It has a short delay time, high triggering accuracy, long working life, and strong anti-interference ability.. In the early studies of LTVSs, the researchers used a laser to irradiate the cathode directly to generate the initial plasma This method produced a small amount of plasma, resulting in low switch performance and severe ablation of the electrode material, which affected the switching life. The simulation results were compared with the experimental results and agreed with them

EXPERIMENTAL APPARATUS

Delay time of the LTVS

Simulation results

Experimental results

CONCLUSION