Calculation of LTE Spectral Opacities for ICF Plasma Mixtures using an Average Atom Model

摘要

The accurate computation of radiative opacities is basic in several-research fields such as astrophysics, or ICF target physics analysis. Radiation hydrodynamics codes for simulation of ICF taigets need the use of detailed spectrally resolved opacity functions for each temperature and density condition. These calculations require a large computation time not only for high Z plasmas but in the case of mixtures as well. For this reasorvsimplified but accurate computation models are needed to be used in-line with hydrodynamic codes. We use the ATMED code to compute the opacity of plasma mixtures under LTE conditions in the average atom framework using a Screened Hydrogenic Model based on a new set of screened constants mcluding the relativistic splittmg of the energy levels. To validate the code we have carried out the computation of spectrally resolved and Rosseland and Planck mean opacities for several plasma mixtures of elements which are of interest for radiation driven imploding shells (ablators) of ICF capsules. The results are successfully compared with similar ones found in the literature.