Spark Chamber Pulsing System

A spark chamber pulser is described in which several avalanche transistors and a step-up transformer drive directly an air spark gap whose trigger electrode is surrounded by barium titanate dielectric. Output pulses of from 1 to 25 kV with a risetime of 1 nsec and an output impedance of less than 1 Ω can be obtained. The total delay from the 1-V input pulse to the high voltage output pulse ranges from 17 to 65 nsec depending on the desired voltage and the mode of operation of the spark gap. Jitter times are less than 3 nsec. When Elkonite-tipped electrodes are used, the gap life is in excess of 5 000 000 pulses. Methods are given for reducing the delay to less than 25 nsec at 20 kV and the recovery time to less than 200 μsec at 10 kV.