Experimental Investigation on a Long-Conduction Time-Plasma Opening Switch and its Application on a 0.1 TW Generator for Prepulse Suppression

Our laboratory has been working for the last three years on plasma opening switches (POS). After characterization of the plasma created by plasma guns[l], we investigate in this paper physical processes occuring during long-conduction-time [2] POS operation using diagnostics such as Rogowski coils, Faraday cups, time-integrated and streak photos. The importance of different parameters of our system, such as the generator charging voltage, the geometry of the switch and the plasma density, have been studied. Our results are correlated with two theoretical models, and the experiment shows that the use of an 80% transparent inner electrode can significantly increase the opening speed. In the second part of this paper, we applied the POS in a short-conduction-time experiment. We are presenting results obtained in upgrading a 0.1 TW generator (2 Ω, ~250 kA, ~50 ns). The prepulse suppression has been 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.