Stephen David Bond

Resolving radiation transport fields subject to opacity profiles with strong, oscillatory line structure while potentially falling under intermediate optical depth conditions presents a numerical challenge in radiation transport modeling. The Young measure-based homogenization technique formulated by Haut et al. (2017) was investigated as a candidate method for resolving radiation fields under such conditions more accurately. The method was compared against frequently-utilized mean opacity methods as the Rosseland and Planck formulations. In this work, all methods were tested through radiation slab calculations separately comprised of aluminum, copper, and krypton, each for different thermodynamic conditions. Following these offline radiation slab calculations, demonstrations shifted towards the SCEPTRE radiation transport code and, subsequently, the multiphysics ALEGRA code for approximately-coupled radiation-material simulations. Throughout all the simulations shown in this study, for a fixed computational cost, the homogenized method was observed to be more accurate than any of the solutions determined through traditional mean opacity approaches.

• FLEXO (Flux-Limited Extended-MHD Ohm's Law) is a production-line extended-magnetohydrodynamics (MHD) code being developed at Sandia National Laboratories for modeling high-energy-density (HED) plasma in a pulsed-power device, primarily with applications to the study of inertial confinement fusion (ICF). Results are presented from various verification and validation tests of extended-MHD and multi-material modeling capabilities.