Studies of plasma formation from exploding wires and multiwire arrays using x-ray backlighting

Abstract

Plasma formation from exploding individual wires and multiwire arrays, powered by a 450 kA, 100 ns pulsed power generator has been studied with x-ray direct backlighting using one or more X pinches as a source of radiation. Experiments have been carried out with many different wire materials ranging in Z from Al to Au. A point source of x rays is used to cast a shadow image of the object plasma directly on film (“point-projection” backlighting). Spatial resolution in the range 1–5 μm, and temporal resolution of 0.7–2 ns, has been achieved using 2–4 keV x rays from Mo wire X pinches. Different schemes for multiframe imaging are described. We also present observations of micron scale structure on residual dense wire cores 40–70 ns after the start of the current pulse.