Characterization of high power gas switch failure mechanisms

A multistage, 4 MV, low jitter, command triggered gas switch is being developed for use on large pulse power devices. Experiments to date have shown that the performance and operational life of the switch are severely limited by mechanical and electrical failure of the insulating housing. Estimates of the internal overpressure produced during switch closure have been made which indicate the severity of the blast containment problem; this information has led to the development of a mechanically stronger switch design. Surface analyses performed on both switch electrode and insulator surfaces were used to investigate observed electrical failure of the insulators. A layer of closely spaced metal particles were found imbedded in the insulator walls.