Low jitter, high voltage, repetitive laser triggered SF6 gas insulated spark gaps

The Electra pulsed power system at the Naval Research Laboratory uses four laser triggered SF6 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.