Radiation transport for R-Z modeling of Z-pinches: Validating and optimizing ray tracing methods with Monte Carlo solutions

Abstract

Radiation, mostly soft x-rays, plays a critical role in the dynamical evolution as well as in the diagnosis of Z-pinches. Detailed MHD modeling is an important tool in gaining basic physical insight into their behavior and in guiding experiments and load design. With radiation dominating the energy budget, it is therefore important to employ the most realistic treatment of radiation generation and transport as is feasible when weighing overall computational demands of the model against available resources. The present work is focused on extending practical yet accurate numerical methods for radiation transport from the one-dimensional to the two-dimensional regime, subject to a self-consistent coupling with detailed configuration atomic models. Our approach is based on equal weight quadratures1, and can describe transport in spectral lines by using either a frequency grid or a line-profile-averaged attenuation function2.