Stainless steel and copper wire arrays in the recent campaign on the UNR Zebra generator with application to larger facilities

The university-scale pulsed power facilities that produce Z-pinch plasmas are a cost-effective measure that provides a blueprint for scaling results to larger facilities like the SNL-Z machine. We successfully conducted a new experimental campaign on the 1-MA Zebra generator at UNR in March 2025 with novel wire array load configurations such as Double Planar Wire Arrays (DPWAs). Although a wide range of wire materials has been studied during this campaign, we present and discuss the results for mid-atomic-number DPWAs with a major focus on soft and hard x-ray plasma spectroscopy and imaging data as well as hard x-ray diode measurements of continuum emissions. Specifically, we consider stainless steel and copper wire arrays because of a renewed interest in studying continuum hard-photon K-shell yields from wire array Z-pinch implosions of these load materials for "warm" >15 keV x-ray production, and we discuss how to apply this to the future next-generation pulsed power facilities (see, for example, a recent joint NRL-SNL paper by Velikovich et al, IEEE TPS, 2024). We demonstrate high total radiation yields of up to 23 kJ with the ionization of substantial fractions of iron and copper ions to He-like states at stagnation and discuss ways of increasing it even further.