SOS diodes

SOS diodes – nanosecond semiconductor opening switches with high current density – have been developed. The devices are intended to produce high-voltage pulses by means of a current cutoff in inductive energy storages.

The devices have the following parameters:
voltage pulse amplitude	up to 200 kV
cutoff current	up to 10 kA
current cutoff time	1 to 20 ns
voltage pulse duration	up to 100 ns
recovery time	less than 1 µs

Series and parallel connection of the SOS diodes into a common unit makes it possible to develop opening switches having a megavolt operating voltage and a gigawatt switching power in combination with a pulse repetition frequency of over 1 kHz.

(a) External appearance of SOS–200–8 stack (peak voltage – 200 kV, cutoff current – 8 kA, diameter – 64 mm, length – 156 mm, mass – 760 g): 1–cathode electrode; 2–anode electrode; 3–stack of the series connected diodes and coolers; 4–cooler; 5–elementary SOS diode

(b) External appearance of SOS–50–1 stack (peak voltage – 50 kV, cutoff current – 1 kA, diameter – 27 mm, length – 50 mm, mass – 30 g).