HEDP produced on the university-scale Z-pinch generators: From X-pinches to wire arrays and applications to astrophysics

Summary form only given. A university-scale Z-pinch generator is able to produce HED plasmas within a broad range of temperatures and densities depending on the type of load configurations and wire materials. Experiments with very different Z-pinch loads were performed on 1 MA Zebra generator at UNR and analyzed during the last five years: X-pinch, Cylindrical, Nested, and various types of Planar Wire Arrays (PWA). X-pinches are very good sources of x-rays and can be used for studying radiative properties of high density (>10²² cm^-3) and temperature (> 2 keV) plasmas with scales from a few ?m to several mm in size. They yield short (few nsec) x-ray bursts from one or several bright plasma spots near the wire cross point and produce strong electron beams as well as plasma jets. PWAs, a new type of the wire array load, were tested in single and multi-plane configurations. It was shown that PWAs may produce significant radiation yield in a ns-scale (up to 25 kJ) and generate bright spots of sub-mm size. The main focus of this presentation is the comparative analysis of the results from recent experiments with the X-pinch, Cylindrical and Nested Wire Arrays and PWAs made from stainless steel wires. The diagnostic set included XRD and PCD detectors, laser shadowgraphy, x-ray time-gated and time integrated imaging, time integrated spatially resolved spectrometers for harder (K- shell) and softer (L-shell) x-ray regions, and a time-gated spatially integrated spectrometer for the softer (L-shell) x-ray region. The non-LTE kinetic, WADM, and MHD codes are used to guide the analysis of the results. In particular, the new results for X-pinches with different angles between the wires are presented and their relevance to astrophysics is demonstrated. The new results from the experiments with above-mentioned wire array loads focus on the study of precursor formation as well as plasma evolution at the stagnation phase. The unique properties and HED f- atures of such plasmas are summarized and discussed.