Strongly coupled, radiative shock experiments on the Omega-60 laser facility relevant to type Ia supernova and neutron star envelopes

Compact objects are some of the most extreme environments in nature. The experiments described here is relevant to two of aspects of compact objects: the shock in double detonation type Ia supernova and the signatures of a neutron star envelope. The work of Shen et al. suggests that thermonuclear eruptions in helium layers on white dwarf surfaces could lead to converging shocks that ignite C/O white dwarf stars. Additionally, the envelopes of neutron stars can reach keV temperatures and densities of a few hundred g cm^-3.

This work will show results from recent experiments at the Omega-60 laser that implode capsules with Al, Ti, and Ni layers on the interior surface. Simulations suggest that the ion coupling parameter ranges from 4 to 12 in the radiative, rebounding shock, depending on the inner layer material. The experiments use spectral measurements and framing camera images to understand the ionization and observe the shock propagation. The analysis uses a ray-tracing approach to compare the simulations to the measured spectra.