Close jitter and discharge process of a pulse-triggered six-stage gas switch

Multi-stage gas switches have been widely used in linear transformer drivers (LTD). To realize the waveform modulation and recurrence for a LTD, multi-stage gas switches are required to operate with a low closing jitter. By increasing the voltage ratio and the trigger voltage, the closing jitter of multi-stage switches can be decreased. However, a low voltage ratio is essential to the low pre-fire probability, and a low voltage pulse is necessary for a trigger system to be cost effective and easily maintained, which is important especially for a large LTD accelerator. In this paper, trigger properties of a six-stage gas switch are described. It is found that the switch closing jitter exponentially declines with the product of trigger voltage and voltage ratio. Using a ultra-violet fiber system, the switch discharge process is diagnosed to show that the trigger pulse and voltage ratio primarily influence the jitter of the triggered gap discharging first, and has little effect to the jitter of the last two breakdown gaps.