A transportable 500 kV, high average power modulator with pulse length adjustable from 100 ns to 500 ns

Physics International has developed and demonstrated a repetitive pulsed power system capable of producing up to 500 kV into a 50 Ω load at low repetition rates and to 400 kV at 100 Hz. This transportable system has demonstrated 100 Hz operation in 10-second bursts. Prime power is supplied by a diesel generator. The pulsed power system consists of a two-stage thyratron-switched modulator, which pulse-charges an eleven-section ladder-network PFN through a step-up transformer (produced by Stangenes Industries). The number of active PFN sections can be selected to allow adjustment of the output pulse duration from 100 ns to 500 ns in 50 ns increments. Section capacitors are water-dielectric coaxial capacitors. Section inductors are oil-insulated coils. The output switch is an air-insulated 1 MV spark gap (produced by PI) with UV illumination to stabilize the self-break voltage. A blow-down air system is used to cool the spark gap and assist in recovery for 100 Hz operation