Low inductance switching studies for Linear Transformer Drivers

We are developing new low-inductance gas switches for Linear Transformer Drivers (LTDs). Linear Transformer drivers are a new pulsed-power architecture that may dramatically reduce the size and cost of future pulsed-power drivers, but which place stringent requirements on gas switches. 1 ,2 A typical large LTD may have 10,000 or more gas switches that are DC-charged to 200 kV and that must be triggered with a jitter of 5-ns or less with a very low prefire rate 3 . We are studying new air-insulated gas switches with total inductances of 68–90 nH. These switches transfer 100 J of stored energy for thousands of shots. Typical 10%–90% current rise-times are less than 50 ns and peak currents are on the order of 40 kA into a matched load. One of the switches has a 1-sigma jitter less than 800 picoseconds. Since triggering 10,000 or more switches is a significant challenge, we are also making a detailed study triggering requirements for these switches. We have previously reported tests of four competing switches for LTDs 4 . In this article we report new tests on improved versions of two of the four switches described previously.