X-ray pulse shaping from tungsten-based multi-planar wire arrays

Summary form only given. An exploration of the shaping of x-ray radiation pulses from tungsten-based multi-planar wire array (PWA) z-pinch implosions carried out on a 1.7 MA, 110 ns university-scale generator is discussed, and an investigation of their radiative properties and implosion dynamics is performed. The experiments were performed on Zebra, the pulse power generator located at the University of Nevada, Reno, with data collected using a full suite of diagnostics that include x-ray diodes, extreme ultraviolet (EUV) diodes, optical imaging, shadowgraphy, time-gated and time-integrated x-ray pinhole imagers, time-gated, spatially integrated x-ray and EUV spectrometers, time-integrated, spatially resolved soft and hard x-ray spectrometers, and a Faraday cup. Three load types that showed particularly diverse and useful results are explained in detail. The first consists of double planar wire arrays built from two planes of wires of different materials, specifically tungsten and another lower-Z element such as aluminum. The second are triple planar loads, which consist of three parallel planes of wires. Like double planar loads, pulse shaping with triple planar arrays could be varied by using alternate wire materials, but an analysis of uniform loads in which the mass of the center array was significantly different from that of the outer arrays showed particularly interesting results. Third, we investigate the pulse shaping of skewed wire arrays. These arrays are similar to standard double planar wire arrays, but the wires in parallel rows are set at an angle opposing one another. These three load configurations were used to create a diverse set of pulse shapes, including pre-pulses of various intensities prior to the main x-ray burst, and “steps” on the front of the main pulse. The possible application of these results to inertial confinement fusion and radiation physics experiments is also discussed.