Low jitter, high voltage, repetitive laser triggered SF 6 gas insulated spark gaps

The Electra pulsed power system at the Naval Research Laboratory uses four laser triggered SF 6 gas switches to transfer the stored pulse forming line energy to the load. Each switch has a hold-off voltage of more than 1 MV and transfers a charge of up to 10.5 mC per shot, with a switch current peak amplitude of 60 kA. The gas switches were originally constructed with hemispherical shaped electrodes. Continuous operations at repetition rates of up to 5 pulses per second showed increases in the switch jitter and switch misfire rates. A redesign with flat electrodes, which provide a more uniform electric field in the switch gap, showed a decrease in switch jitter.