Probing the structure of multi-ion-species plasma shocks with spatially resolved spectroscopy

This presentation highlights an investigation into the structure of shock-compressed multi-ion-species plasmas, induced by the collision of a freely-expanding supersonic plasma jet with a quasi-stagnant background plasma. Previous results have shown that the piston-like action of the supersonic jet serves as a snowplow, compressing background material with a density enhancement that suggests collisional shock formation. By performing spatially resolved spectroscopy in concert with collisional radiative modeling, we report spatial distributions of ion species density, electron temperature and electron density, quantifying the transition from pre- to post- shocked flow. Of particular interest is understanding the role of diffusive mass-flux near the shock front, where it has been predicted that large gradients in plasma parameters can induce species separation. The structure of multi-ion-species plasma shocks is also relevant to the study of supernovae events where the effects of non-LTE physics within the shock remains an open topic of interest. We expect that these results will contribute to the growing database of studies meant to benchmark physics models of plasma shocks in both laboratory and astrophysical settings.