Firing characteristics of a miniature laser-triggered high-voltage vacuum switch

Summary Form only given, as follows. A miniature laser-triggered high-voltage vacuum switch with a fused KCl and Ni cathode has been developed. 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 to 40 mu J of laser energy. The switch was operated with a gap voltage ranging from 500 V to 3 kV with switching currents up to 5 kA peak. A switch life greater than 1000 shots without performance degradation has been observed on 25 prototype units. The function time of the switch varies from 10 ns+or-1 ns at 3 kV to 200 ns+or-100 ns at 500 V. Improved performance over a previously reported switch is derived from the fused KCl cathode, a lower inductance of switch and circuit, and the use of an ultra-high-vacuum switch that receives a 600 degrees C bakeout and is pinched off from a vacuum manifold in the 10/sup -9/-torr range. The switch triggering mechanism and the switch turn-on characteristics can be studied more clearly, since a higher-quality vacuum switch and a lower-inductance circuit are being investigated.<>