Study of the Stability of Triggering of a Controlled Multigap Spark Switch for Capacitive Energy Storage with Charging Voltage up to 100 kV and Energy Release Time on the Order of 100 ns

Abstract

Results are presented of a study of the stability of triggering of a six-channel seven-gap spark switch intended for switching a capacitive energy storage with a charging voltage of up to 100 kV and energy release time on the order of 100 ns. The working medium of the spark switch is air at atmospheric pressure. In the controlled triggering regime, we measured the breakdown delay time of all of the discharge gaps relative to the arrival of the voltage trigger pulse and calculated the mean square deviation of the delay time (jitter) under variation of the charging voltage and growth rate of the voltage trigger pulse. Jitter less than 1 ns was obtained for a charging voltage of 90–100 kV and a growth rate of the voltage trigger pulse ~650 kV/μs. When the growth rate of the trigger pulse is decreased, the jitter of the spark switch grows significantly. Thus, for a charging voltage of 100 kV and a trigger voltage pulse with growth rate ~200 kV/μs the jitter exceeds 20 ns, and for a voltage trigger pulse with growth rate ~100 kV/μs the jitter exceeds 30 ns. To reduce the jitter when using trigger pulses with low growth rate, blade electrodes were inserted into the spark switch, ensuring ignition of a corona discharge in the gaps during charging of the capacitive storage. It has been shown that for a growth rate of the trigger pulse of 100–200 kV/μs the corona discharge reduces the jitter by 2–3 times.