Producing kiloelectronvolt L-shell plasmas on zebra at UNR

Experiments with various wire loads from mid-atomic-number wires, which were performed on the university-scale 1-MA Zebra generator at the University of Nevada, Reno, during the last few years, are analyzed to assess the highest electron temperature reached. In particular, the results from experiments with planar wire arrays (PWAs) were considered. Load materials from mid-atomic-number such as stainless steel, Alumel, Cu, brass, Mo, and up to Ag were used to generate L-shell plasmas and to study plasma parameters. Though the full diagnostic set was utilized, the main focus was on X-ray spectroscopic data and on the non-local thermodynamic equilibrium kinetic modeling. As a result, the scaling of the maximum T_e with the load material atomic number is presented for the first time in the range from Fe to Ag for L-shell plasmas from PWAs. The highest values of the electron temperature in L-shell plasmas, which are estimated from the modeling, were from both Ag PWAs and X-pinches. This work is important for the development of efficient X-ray radiators on university-scale Z-pinch generators.