Low-loss, high-repetition-rate vacuum switching

The theory and design of a trigatron-configuration vacuum switch are presented. When operated with a series saturable inductor element it functions effectively as a high-repetition-rate closing switch for pulsed power applications. This switch configuration allows one to fully exploit the advantages inherent to a vacuum switch, such as high voltage standoff, wide triggering range, potentially fast recovery, and high repetition rate, while circumventing the disadvantages, namely, poor turn-on performance, large jitter, high-power dissipation, and inconsistent recovery performance. The resulting hybrid switch is capable of high-performance, high-repetition-rate operation. A device of this type has successfully switched multikiloampere current pulses of submicrosecond duration at voltages greater than 40 kV. Compared to an unassisted triggered vacuum gap, a better current risetime was obtained, power dissipation was reduced by 90%, pulse reproducibility was better, a more uniform conduction channel was achieved, microparticle ejection was eliminated, and electrode erosion was significantly reduced. The switch has been operated at pulse repetition rates in excess of 10 kpps