Modifying implosion dynamics of a wire array by using an inverse wire array z-pinch as a current switch

We will describe experiments on the MAGPIE facility (1.5MA, 250ns) 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 ($<$100ns) delivered to a separate, standard imploding wire array z-pinch load. It was found that this arrangement generates a short current pre-pulse ($\sim $5kA, $<$15ns) through the imploding array, followed by a $\sim $140ns 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.