Multi gap, multi channel spark switches

Abstract

The switches that are designed for application in high pulsed power drivers should meet some hard requirements, the main of them being small inductance and big charge flowing through the switch. In order to reduce the inductance and to increase the charge it is preferable to divide the switched current into multiple parallel channels. Such parallel current channels could be obtained in railgap three-electrode switches, or in surface switches, due to electrical field disturbance which occurs when a trigger pulse rising as -10/sup 13/ V/s is applied to the switch. Multi channel discharge could also be realized in multi gap spark switches. We report the results of the multi gap, multi channel switch development performed at the High Current Electronics Institute in order to reach the requirements of the SYRINX project (France). These requirements are: operating voltage 90 kV, switch current >500 kA, current rise time <1/spl mu/s, and switch inductance <10 nH. Different switches are described developed in consecutive steps of our collaboration. In these switches, the multi channel discharge is realized in multi gap spark switch configuration, where the voltage during charging is uniformly distributed between the few gaps connected in series. The triggering occurs due to disturbance of voltage distribution between the gaps when a trigger pulse is applied. The number of parallel current channels is controlled by the number of parallel multi gap chains.