Investigation of Dielectric Flashover in an SF6 Filled Laser Triggered Gas Switch

A study of dielectric flashover in SF6 in a laser triggered gas switch (LTGS) is reported. Flashover occurring on the inside of the insulating barrier of the switch leading to the eventual failure of the switch was studied. The University of Missouri-terawatt test stand is testing the trigger section of a LTGS to understand and improve the flashover characteristics of these switches. A Rimfire LTGS was modified to operate with a trigger gap voltage of 938 kV. The modified switch was tested repeatedly over a range of pressures to examine the sensitivity of switch flashover to several parameters. The aspects of the switch that were tested include triple points both due to asymmetrical torque on the endplates, and due to gaps between the insulator and endplate, and the effect of slower voltage risetime. An analysis of the early findings of this study is presented