Highlights of the most recent wire array campaign on the UNR Zebra generator

Previously, we have demonstrated that the implosion of optimized high-atomic-number wire loads almost always produced hot and dense plasmas that radiate a rich spectrum of soft x-rays and strong characteristic line radiation. The latter is believed to be caused by inner-shell ionization of neutral atoms by non-thermal electron beams propagating through the cold thermal plasma. To expand it further, we initiated research on continuum emission from Z-pinches (in the energy range below 30 keV), in combination with x-ray line radiation studies. Here we present a few highlights from our most recent wire array campaign on the UNR Zebra generator. The wire arrays were double planar wire arrays from a broad range of wire materials with masses up to 180 mcg/cm. The maximum radiation yield of 32 kJ was achieved with the gold (Au) wire array. The results of a few shots with the mid- and high-atomic-number wire arrays were analyzed and compared including radiation yields, soft and hard x-ray plasma spectroscopy and imaging data, hard x-ray diode measurements of continuum, and shadowgraphy. These studies are important for the achievement of better understanding of non-thermal plasmas in general and Z-pinch plasmas in particular as well as for development of efficient x-ray sources for the existing Z-pinch generators and Next-Generation Pulsed-Power Facility.