Development Of A Compact, High-energy Spark Gap Switch And Trigger Generator System

High-energy switches and trigger generators are required for a range of capacitor banks in electric gun applications. We have developed a compact, long-lived spark gap and a matched series-injection trigger generator. The switch is of a two-electrode design using high density graphite electrodes. The demonstrated peak current capability is near 300 kA, with a charge transfer of 700 Cb, and a projected lifetime of 150,000 Cb. The trigger generator is a spiral generator with an open circuit output voltage of 75 kV, a risetime of 60 ns. and a pulse width of 160 ns. The spark gap can be triggered reliably to zero voltage, assuring low prefire rates and allowing for operation as a crowbar switch. The design approach, achieved performance, and application of the switch and trigger system in pulse forming circuits are discussed.