Rad-MHD Simulations of the SNL Opacity Platform

The opacity platform at Sandia National Laboratories is composed of a half-moon opacity sample which is mounted above the dynamic hohlraum X-ray source that is driven by the Z Pulsed Power Facility. The dynamic hohlraum X-ray source which has a central CH foam that is radiatively shocked by a double nested wire array, both heats and backlights the opacity sample. Additionally, the foam plasma can hydrodynamically impact the opacity sample which can affect opacity measurements. To properly simulate the dynamic hohlraum source and its effect on the opacity sample, a radiation-magnetohydrodynamic code is necessary. In this presentation, we show the results of modeling the SNL opacity platform using the code HYDRA. Important criteria to match with experimental results which are necessary for demonstrating the quality of the simulation are 1) the radiative shock speed in the CH foam and 2) the radiation output from the source. These simulations highlight our understanding of the existing opacity platform and provide a basis for future designs of the platform. We will also discuss steps for inferring and comparing simulated opacity sample conditions, i.e. electron density and temperature, with the measured opacity conditions [1].

[1] G. P. Loisel et al, Phys. Rev. Lett. 134, 095101 (2025).