Open L-Shell Spectroscopy of Non-local Thermodynamic Equilibrium Plasmas

Spectral modeling codes are commonly used to infer plasma conditions from measured spectra. However, at non-local thermodynamic equilibrium conditions common in high-energy-density environments, such models produce conflicting results for open-shell systems. Improving the underlying atomic models would improve inference capabilities in such systems, particularly for employing L-shell spectra as a sensitive density diagnostic where traditional K-shell techniques are limited. To begin to provide high-quality data that can discriminate between spectral codes, we present results of time-resolved, open L-shell Ge spectroscopy from Ge and Sc buried layers in 10-$\mu $m-thick Be irradiated by the OMEGA laser. Time-resolved temperature and density are constrained by Sc K-shell spectra and images of the emitting volume. Comparisons to the spectral model SCRAM are explored. This platform will enable systematic measurement of high-resolution, temporally-resolved spectra of open L-shell mid-$Z$ elements.