Current Sharing in the Early Stages of a Wire Array Z-Pinch on the COBRA Accelerator

Summary form only given. In this experiment we examine the temporal evolution of the current distribution among individual wires and pairs of wires in wire array z-pinches using different wire materials (e.g., aluminum and tungsten). To accomplish this we electrically isolate the wires, or pairs of wires, from each other using segmented load hardware. Each segment is able to hold one or two wires and is electrically connected to one return current post. Experimental goals include determining the relative timing of the initiation of coronal plasma around each wire and the effect of the spacing between the wires on that timing. The individual Rogowski coils, calibrated using a separate pulser, record time-dependent current information for each return current post. In addition, optical streak images and laser backlighting images of the wire initiation process are obtained, and a load voltage monitor enables estimates of the energy deposited in the wires during the plasma formation process to be made. Electrical diagnostics are synchronized to a timing accuracy of less than 1 ns.