An enhanced vacuum switch

Operation of a vacuum switching gap in the magnetically delayed mode (with a series saturable inductor) has significantly improved the conduction characteristics of the gap, resulting in a switch more amenable to high-repetition-rate, short-pulse applications. Experiments have shown that the switching plasma fully permeates the interelectrode gap in the short interval following triggering but prior to the high current conduction phase, so that electrode heating is significantly reduced in a comparison to an otherwise similar vacuum switch. The switch plasma dissipated from the gap region in only a few microseconds, much faster than in the vacuum gap. A fast rate of current rise, with a time constant near 10 ns, has been obtained at 45 kV in a 50 Omega system. The results indicate that most, if not all, of the previously poor switching characteristics associated with vacuum gaps have been overcome.