High power hollow cathode glow discharge switches

A new class of high-power diffuse glow discharge switches for peak powers up to ~1 GW has been developed, consisting of the electrically triggered pseudospark switch and the UV-light-triggered BLT. These switches have been shown to work in a superdense glow discharge model, like thyratrons, but without the need of an externally heated thermionic cathode. Peak current densities of 10 kA/cm² have been reached in this mode without arcing. A physical model, together with supporting experimental results, is presented which explains this high current density. The model implies that an essential part of the discharge current is due to ions accelerated in the cathode fall, which leads to the heating of a thin surface layer of the cathode up to a temperature where thermionic electron emission becomes the most essential source of charge carriers