Studies on Principal Igniting Factors of the Initial Breakdown of Trigatron Switches

Investigations have been carried out into the mechanisms leading the initial breakdown of trigatron switches. The experimental work identifying effects of two different igniting factors are described and carried out in detail. One mechanism is when only the UV radiation generated from the ignition gap (gaps between the pin and adjacent electrodes) is applied to the main gap (gaps between the adjacent and opposite electrodes). The UV radiation is believed to produce free electrons through either photoionization or photodetachment in the main gap which in turn leads to the initial breakdown of the main gap. The second mechanism is when both the electron cloud and the UV radiation generated from the ignition gap are applied to the main gap. It is believed that both the electron cloud and the UV radiation result in the free electron in the main gap. Experimental results show that both the UV radiation and the electron cloud resulting from the ignition gap have obvious effects on the initial breakdown of the main gaps. Under conditions here, it seems that the electron cloud plays a more important role on the ignition of the initial breakdown.