Program of Basic Research for High Power Switching and Other High Power Devices

摘要

The study of the physics of thyratron type switches under this contract has led to a new low pressure glow discharge switch that has a number of features that are desirable for high power applications. The switch has achieved high stand-off voltage and peak current (70 kA), has very fast current rate of rise, and operates near the glow-to-ar transition in hydrogen and other gases. It appears to have intriguing scaling possibilities. In addition, we demonstrated a cold, hollow cathode that operates with much higher current densities than dispenser and oxide thermionic cathodes -- without forming an arc. Current densities that are about 2 orders of magnitude over heated cathode current densities -- 10,000 A/sq cm vs. 100 A/sq cm -- have been achieved over cathode areas of approximately 1 sq cm. 20,000 A peak current is readily achieved in a simple, unheated configuration. Finally, in a different area, an optoelectronic bistability in GaP has been observed. The bistable mechanism is based on trap filling, and has possible applications to optically integrated devices. (RQ)