Preliminary experiments on gaseous recovery in gas spark gap switches

Summary form only given: A two-pulse generator for experiments on gaseous recovery in gas spark gap switches was built and tested. The generator could produce two pulses of high voltage up to 60 kV with a variable time interval between these two pulses. A time delay system of high noise-immunity was constructed to control the two-pulse generator and to synchronize the diagnostic instruments with the discharge in the tested spark gap. The information of voltage-recovery in the tested spark gap was obtained using a two-pulse technique where the first pulse breaks down the gap and the second pulse determines the recovery. The dependences of the voltage recovery in the spark gap on gas type, gas pressure, gap length and discharge current were obtained. The instrumentation such as Mach-Zahnder interferometer, fast ICCD camera and time-resolved spectrometer are being prepared for determination of the electron density, radius and temperature of the first spark channel, which is important for modeling and simulation of the gaseous recovery since these parameters are the initial conditions of the recovery.