Research on the conduction process of laser triggered vacuum switch

In this paper, the conduction process of the Laser Triggered Vacuum Switch (LTVS) is studied. First, the velocity, density, and temperature of the initial plasma in the LTVS are simulated using COMSOL Multiphysics software. It is found that the generation and development of the initial plasma are at the ns level. Second, the pre-breakdown current test circuit of the LTVS is established. It is found that when the applied voltage at both ends of the switch is 60 V, the multi-rod LTVS is successfully conducted, and then, the current becomes the conduction current and the voltage applied at both ends of the switch decreases significantly. Finally, the images of the LTVS vacuum arc are taken. With the increase in laser energy, the more abundant the initial plasma is, the lower the required gap voltage is. When the current increases to a certain value, the vacuum arc appears in multiple discharge channels, which makes the arc have a diffusion morphology. It is found that the current withstand capacity of a single channel is about 50 kA. As the multi-rod LTVS has three channels, its current withstand capacity can reach 150 kA.