80-MW photoconductor power switch

The application of photoconductors to fast rise time, high-power switching is discussed. We report the successful switching of a 100-kV system to generate a 1.8-kA, <5-ns rise time, 200-ns duration electrical pulse in a 25-Ω load using a single photoconductor switch excited by a Q-switched Nd: glass laser. The photoconductor was a 2.5-cm-long bar of single-crystal, high-resistivity silicon with a 0.5×0.5 cm cross section. Only a depth of about 1 mm of one side was used for conduction.