Design and test of a modular trigger generator for over-voltage triggering of Marx generators

Over-voltage triggering of a spark gap enables a synchronized operation of several Marx generators in repetitive operation without an increased wear of the electrodes. The trigger pulses are generated by means of a pulse generator consisting of several stacked stages, which are equipped with IGBTs as opening switches. A pulse transformer serves as intermediate energy storage. It replaces one charging coil between the first and second stage of the Marx generator and couples the trigger pulses into the Marx circuit causing an over-voltage across the 1ststage's spark gap. The number of stages of the trigger generator can be varied in order to adapt the trigger generator to different Marx generator designs with varying stray capacitance and breakdown voltage of the spark gap. The paper describes the design of the trigger generator and presents the results of tests.