Low inductance triggered multichannel surface switch for inductive energy storage generator

A very low inductance pressurized surface discharge switch has been developed for an inductive energy storage generator. This switch was developed as an integral part of a strip-line MARX assembly. This technology performed reliably up to 50 KV - 700 kA with a switch inductance as low as the inductance of the equivalent strip-line. The measured inductance was less than 4.5 nH. Part of this development was done to improve the reliability of the switch and its electrical characteristics including the effects of the trigger pulse on the current distribution along the width of the strip-line. We will show that jitter and current distribution can be controlled by the trigger pulse voltage and rise time. For the first quarter period of the discharge we correlated the number of channels during operation with the trigger pulse parameters. We carried out experiments to estimate the main characteristics (self-breakdown voltage, number of channels, self inductance, peak current discharge value) of such a switch for different gases (synthetic air, SF₆, SF₆/N₂O₂ mixture). Optimized parameters are deduced. These studies give us a model of switch operation which enables this kind of design for very low inductance multi-megajoule systems.