Experimental study of an inverse wire array z-pinch operating as a current switch

Abstract

Summary form only given. We will present experiments on the MAGPIE facility (1.5 MA, 250 ns) in which an inverse wire array (with the wires acting as a return current cage placed around a central current conductor) operated as a fast current switch. This allowed to significantly reduce the rise-time of the current pulse (<; 100 ns) delivered to a separate, standard imploding wire array z-pinch load. Experimental studies of the operation of this arrangement as a current switch will be discussed. In particular it was found that this arrangement generates a short current pre-pulse (~5 kA, <;15 ns) through the imploding array, followed by a ~40 ns interval with zero current, before the main fast rising current pulse is switched into the array. This led to a significant change in the implosion dynamics, suppressing the ablation phase, introducing a 0-D-like implosion and reducing the level of trailing mass.