Investigation of a high voltage vacuum insulator for the DARHT accelerator

Tetra has optimized the design of the Microstack vacuum insulator based on previous Microstack results and a specific series of experiments at Tetra's facilities for operation on the DARHT accelerator. Over 30 insulators have been tested with variation in the ratio of insulator to conductor thickness, and various overhangs of the conducting rings relative to the insulator. The insulators were tested on Tetra's MegaMarx generator at electric field levels of greater than 200 kV/cm and pulse-widths of 2 /spl mu/s. A series of tests were conducted to quantify the voltage, flashover characteristics and the leakage current characteristics as a function of the ratio of the conductor overhang to insulation thickness.