Fast power switches from picosecond to nanosecond time scale and their application to pulsed power

New methods of pulsed power are developed on the basis of new effects in high voltage semiconductor p-n junctions, discovered at Ioffe Physico-Technical Institute, Russia. These effects are: (a) super fast voltage restoration; and (b) super fast reversible delayed breakdown. These effects have been used to design two types of semiconductor device: (1) opening switches-drift step recovery devices (DSRD) with turn off times 0.5-2.0 ns at operating voltages 0.5-2.0 kV for one p-n junction; and (2) closing switches-silicon avalanche shapers (SAS) with turn on times 50-200 ps at operating voltage 3-10 kV for one p-n junction. DSRD may be considered as a solid state replacement for plasma opening switches and SAS may be considered as a replacement for overvoltaged spark gaps. Both types of devices may be assembled in a stack (piled) with dozens of p-n junctions to increase operating voltages. Estimations show that operating voltage for the stack can reach 1 MV in the case of DSRD with turn off time /spl sim/1 ns and hundreds kV in the case of SAS with turn on times /spl sim/0.1 ns. It is possible to switch all areas of devices uniformly up to the limitations imposed by skin effect. Estimations show maximum switching current up to 10 kA for DSRD and >2 kA for SAS.