Photoconductive Switches Vacuum Surface Flashover Improvements

Photoconductive semiconductor switches (PCSS) presently have the greatest potential for dramatic performance enhancements for high power pulsed applications. However, surface flashover severely limits the maximum stand off voltage in the open state. We report the use of a novel technique to PCSS to overcome this limitation. The technique is an extension of the graded ring bushing idea from accelerator technology but differs by reducing the thickness of the insulatorv (semiconductor) down to tens of micrometers. The results indicate a 40% improvement of GaAs and a 75% improvement on silicon samples.