Experimental investigation on a long-conduction time-plasma opening switch and its application on a 0.1 TW generator for prepulse suppression

The authors discuss their work on plasma opening switches (POSs). After characterization of the plasma created by plasma guns, physical processes occurring during long-conduction-time POS operation are investigated using diagnostics such as Rogowski coils, Faraday cups, and time-integrated and streak photographs. The importance of different parameters of the authors' system, such as the generator charging voltage, the geometry of the switch, and the plasma density, are studied. The authors' results are correlated with two theoretical models. The experiment shows that the use of an 80% transparent inner electrode can significantly increase the opening speed. The POS is applied in a short-conduction-time experiment. Results obtained in upgrading of a 0.1-TW generator (2 Ω, ~250 kA, ~50 ns) are presented. Prepulse suppression is achieved with a short-circuit load and with an aluminum vapor Z-pinch as a load. Incorporation of the POS improves the compression of the Z-pinch and increases the radiation yield