High-repetition rate, commercial pseudospark switches for pulsed modulators

Experimental results of high-repetition rate pseudospark switch testing are reported. High-repetition rate operation was investigated with special regard to applications including copper vapor lasers, high-repetition-rate high-average power excimer lasers, and linear induction accelerators. Typical test parameters are hold-off voltage on the order of 15-25 kV, peak currents on the order of 10 kA, and pulse durations on the order of 50 to 100 ns. The discharge circuit used for testing was contained in a coaxial housing, using discrete ceramic capacitor of 5.4 and 10.8 nF total. The circuit impedance achieved was on the order of ≈1 to 2 Ω, which resulted in peak currents on the other order of 10 kA in the short-circuited, ringing discharge. Current reversal under these conditions was up to 80% of the peak current. A sealed-off, metal-ceramic pseudospark switch with integral hydrogen reservoir tested in the setup achieved repetition rates of up to 1.8 kHz without latching or triggering failures. Some 10⁷ shots have been performed without degradation of the switch performance