Opacity calculations. Ge and Si dopants in ICF

Abstract

International audienceWe have calculated the opacity spectra of mixtures, carbon + dopant, for various densities and dopant fractions. We present detailed line shape calculations where almost all spectral broadening effects are taken into account. These calculations are able to provide accurate opacity spectra but they rapidly become prohibitive when the number of lines is large. To account for many ionic stages and millions of lines, hybrid methods are preferred. The hybrid methods combine detailed line calculations and statistical calculations. In spectral regions where the lines are sufficiently separated and the number of radiative transitions is moderate, detailed calculations are feasible. When the number of transitions is very large most of them merge into broad structures, due to line broadening, so that statistical calculations are unavoidable. The hybrid calculations are more appropriate for opacities where large numbers of lines need to be included because they are faster than the full line-by-line calculations. In this work we concentrate on silicon and germanium dopants