Ultra fast, high rep rate, high voltage spark gap pulser

Abstract

This paper discusses our on-going program at the US Army Pulse Power Center to develop an ultra-fast spark gap based impulse generator. Our approach involves capacitively charging coaxial cables in a Blumlein configuration and discharging the PFL using a self breaking, unpressurized, air spark gap. With this technology we have achieved pulses with peak powers of 2-4 megawatts into a 100 /spl Omega/ load at repetition rates of several kilohertz. By incorporating a sharpening gap, also air at one atmosphere, we have demonstrated pulse rise times on the load of slightly less than one nanosecond. New spark gaps have been designed and implemented which have allowed high pulse repetition rates at high voltages by passing flowing gas between the electrodes. This allowed the modulator to run at 20 kV and a 15 kHz pulse repetition rate. A high pressure spark gap was designed to achieve pulse rise-times of a few hundred picoseconds. The gap was DC tested at a pressure of 20 atmospheres.