Switching characteristics of a gas trigatron operated in single and double trigger mode

The delay time, risetime, jitter, and operating range have been studied in detail for single- as well as double-trigger mode. The best switching performance is obtained in a double-trigger mode for a trigger polarity configuration that produces high field intensification between the opposed trigger electrodes. For a trigatron with a gap spacing of 9.7 mm, using air at atmospheric pressure, an operating range of 12 to 28 kV with low delay time (<100 ns) over the entire operating range and a low jitter (<4 ns) have been obtained. An interesting regime of substantial current dip during the main gap current growth has been found. It is indicative of blowout of the first auxiliary spark channel by the shock wave produced by the second auxiliary spark channel. The successive stages of formation of auxiliary spark channels and the way in which they lead to trigatron breakdown by either a generation or a streamer mechanism are discussed in detail. The results establish the superior switching performance of a double-mode trigatron over the conventional single-mode trigatron and give new insight into the mechanisms operating in the former.<
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