Pulsed Power Technology for Aerospace Applications

Many applications exist for high-power, high repetition rate, long-life switches in Air Force missions. While considerable progress has been made in the art of high-power switching over the past few years, the switch rise time, life time and rep rate forportable, small-scale pulse power systems still requires improvement for present and future Air Force applications. For generating high-peak-power (> GW) pulses at high rates, the use of spark gaps with liquid dielectrics as switch media is proposed ratherthan the commonly used gas switches. Because of the high dielectric strength of polar liquids (on the order of 1 MV/cm), liquid dielectric switches require relatively small electrode gaps. The small switch volume makes it possible to remove the liquidquickly after each shot. By integrating the switch into a flow system, a switch volume with typical dimensions of several hundred microns can be replaced in less than 1 ms (kHz rep rate) for a flow velocity of 1 m/s while retaining rise times of 1 ns orless. It is proposed in Phase I of this project to study the characteristics of water switches in static and flow modes and to use the results to determine the potential of these switches for kHz-rep rate operation. Phase II will be focused on theoptimization of the switch at realistic power levels and rates. In addition, we will include the concept of polar liquids as dielectrics in the Pulse Forming Network as a means to reduce the size of the high-power pulse generator. Also addressed will bethe problem of low-jitter triggering of liquid dielectric switches; applications in the generation of large-volume, high-pressure plasmas for