STREAMER MODEL FOR IONIZATION GROWTH IN A PHOTOCONDUCTIVE POWER SWITCH

The ionization process in a high gain photoconductive GaAs power switc h is explored computationally, based on a streamer model, The streamer velocity was found to increase with increasing electric field, decrea sing temperature, or increasing background ionization density, The ele ctric field dependence of streamer velocity is consistent with experim ental observations, lending support for the model's predictions about the temperature and background ionization density dependencies, The la rge electric field associated with the highly charged streamer tip all ows virtual propagation of the ionization column at speeds above 10(8) cm/s, well in excess of the carrier saturated drift velocity.