Silicon carbide as electrode material of a pseudospark switch

Through the last years, the pseudospark switch, a low-pressure gas discharg e switch with hollow cathode geometry, became established as a promising el ement of pulsed power technology and a serious alternative to other high-po wer switches. The use of a novel electrode material silicon carbide yields performance improvements in two main areas. Quenching phenomena, a long-sta nding problem for several applications, are suppressed completely and the s witch lifetime can be distinctly increased, approaching that of thyratrons for operation with high repetition rate. As crow-bar switch, lifetime is ne arby unlimited due to cold electrode usage. Spatial and temporal resolved s pectroscopy revealed new insight into the extraordinary discharge behavior of silicon carbide electrodes, The radial plasma expansion from the central bore hole to outer electrode regions, forming vesicular shells of differen t ionization stages of Si and C, will be described in detail. The remaining problem, a significant loss of deuterium gas during discharge, has been lo ng-term tested and is assumed to be the outcome of absorption in the silico n carbide electrodes, An envisaged promising remedy is presented.