Establishing a Laboratory Benchmark to Diagnose Astrophysical Plasmas using the Fe/Ni Intensity Ratio*

Plasma is an ionized, collectively-behaving gas that constitutes >95% of observable matter in the universe. Through laboratory-produced, high-energy-density (HED) plasmas and high-resolution spectroscopy, the ability to probe physical parameters of astrophysically relevant plasmas is now feasible in a controlled, experimental setting. Astrophysical plasma analysis involves computational spectroscopic modeling to infer electron plasma temperature, density, distribution function, etc. In the absence of these computational models, diagnostics to investigate HED plasmas are relatively incomplete. In this talk, I present a theoretical benchmark to diagnose plasma parameters in lieu of computational models using the Fe/Ni intensity ratio. Fe and Ni are chosen due to their relative abundance in the universe which resembles their relative composition in stainless steel alloy wires used in the production of HED Z-pinch plasmas. Theoretical line intensities are produced with the Spectroscopic Collisional-Radiative Atomic Model and Fe/Ni ratios tabulated for a range of plasma parameters. An example of the application to experimental HED plasma data is presented.