Low-Inductance Gas Switches for Linear Transformer Drivers

Summary form only given. We are investigating several alternate gas-switch designs for use in linear transformer drivers. To meet linear-transformer-driver requirements, these switches must be DC charged to 200 kV, be triggerable with a jitter of 5 ns or less, have very low pre-fire and no-fire rates, and have a lifetime of at least several thousand shots. Since the switch inductance plays a significant role in limiting the rise time and peak current of the LTD circuit, the inductance needs to be as low as possible. The switches will be required to conduct current pulses with ~100-ns rise times and 20-80 kA peak currents, depending on the application. Our baseline switch, designed by the High Current Electronics Institute in Tomsk, Russia is a robust six- stage switch with an inductance on the order of 120 nH that is insulated with 30-40 PSIG of air. We are also testing two smaller two-stage switches that have inductances on the order of 60 - 70 nH. The smaller switches are insulated with 100-200 PSIG of air. We will discuss details of the operation of each of the switches, including voltage hold-off, triggerability, and lifetime testing.