Experiments with UV Laser Triggered Spark Gaps in a Stacked Blumlein System

Very compact pulsed power systems can be fabricated with stacked Blumlein lines (SBL). The critical component necessary to field a viable SBL system is the switch that is integrated into one of the two transmission lines that forms each Blumlein in the stack. The critical parameters of the switch are the current inductive time constant, the switch resistive phase closure time, and the switch closure jitter all of which must be much lower than the desired load pulse risetime. Another important consideration / requirement is the method of triggering the switches in the stack, which should be compact and provide high voltage isolation while delivering very precise, controllable switching. This paper discusses switch requirements from basic circuit analysis and the experimental setup, parameters, and results of an experiment to investigate the feasibility of UV laser triggering of up to 40 Blumlein lines in a very compact SBL. In addition, the method of fabricating a very compact SBL transmission lines is presented. Then the behavior of the switch parameters in the stack when closure is initiated with a UV laser pulse is presented. Specifically, the time varying inductance and resistance of the laser initiated gas discharge channel is presented and compared with a circuit model to elucidate the switch performance.