Firing characteristics of a low-jitter miniature laser-triggered vacuum switch

A miniature laser-triggered high-voltage vacuum switch with a fused KCl and Ni cathode is discussed. The switch uses metal-ceramic construction with a sapphire window in the anode to allow the laser beam to strike the cathode surface. Reliable triggering is achieved with only 20 μJ of laser energy. The switch was operated with a gap voltage ranging from 500 V to 3 kV, with switching currents up to a 5 kA peak. Switch life greater than 1000 shots without performance degradation has been observed on 50 prototype devices. The function time of the switch varies from 10±1 ns at 3 kV to 100±50 ns at 500 V