High-Coulomb spark gap for electric guns [pulsed power supply]

An extremely rugged spark gap capable of handling currents and charge transfers of interest for electric guns was designed and demonstrated. The switch has been demonstrated with peak currents over 850 kA, charge transfers over 300 C/pulse, and action over 220 MJ/Ω each pulse. At this duty, switch electrode life is estimated to be approximately 100 shots before electrode tips must be replaced. Lower charge transfers result in proportionately longer electrode tip life. Electrode tip replacement, which is performed along with cleaning of the insulator, is a simple process requiring 10 to 15 minutes per switch. Switch design ensures that the arc will lie along the centerline of the switch, balancing forces on all parts of the switch. This allows a very rugged switch design without excessive weight. Triggering of the switch is accomplished in a series triggered mode, allowing operation of the switch at less than 50% of its self-break voltage, giving prefire probabilities of less than 10^-6 per pulse. Demonstrated switch performance, the triggering approach, and application to electromagnetic and electrothermal gun circuits are discussed