A new gas discharge switch for discharging high energy capacitor banks

The performance of a new type of high voltage gas-discharge switch is described. The switch is intended primarily for discharging high energy capacitor banks such as may be used in laser fusion and plasma experiments. The switch is capable of holding off high voltage with very high reliability against prefires, or self-commutation events. Other features are: high peak current capability with a large coulombic transfer per pulse, a large dynamic range, ease of triggering and long shot life. These characteristics are substantiated by tests carried out in a purpose-built capacitor bank facility, which is also briefly described. The test equipment has been designed to operate the switch with a hold-off voltage of 30 kV, and produce a near critically-damped current pulse of 80 kA with a coulombic content of 37 coulombs, at a shot-rate of 1 per minute. A lifetest under these conditions has been carried out, and the switch has successfully completed over 5000 shots without any prefires. At this point the lifetest was halted, although the switch was still operational. Other general switch characteristics such as firing delay, jitter, anode fall time and trigger requirements are also described.