Design and development of a 1 MV, compact, self break switch for high repetition rate operation

The design of compact, high voltage switches is generally plagued by the tradeoff between reduced size and the probabilities of bulk and surface breakdown. Moreover, typical breakdown field values for wide classes of materials with desirable electrical and mechanical properties are unavailable. In the development of a compact gas switch, capable of holding off voltages of up to 1 MV at repetition rates of 200 Hz, a criterion to insure the inhibition of surface flashover in a high pressure atmosphere has been developed. The switch is composed of copper tungsten electrodes with a coaxial Torlon pressure containment housing of length 12.7 cm and a diameter of 15.3 cm. Pulse repetition rates in the 100's of Hz are achieved by using moderate hydrogen pressures as the insulating medium. The electrodes are shaped to produce a uniform field distribution in the gap with an adjustable spacing of 0.5, 0.75 and 1.0 cm. Additional stress is put on the switch by charging with a dual-resonant pulse transformer.