Radiative opacity of iron studied using a detailed level accounting model

Abstract

The opacity of iron plasma in local thermodynamic equilibrium is studied using an independently developed detailed level accounting model. Atomic data are generated by solving the full relativistic Dirac-Fock equations. State mixing within one electronic configuration is considered to include part of the correlations between electrons without configuration interaction matrices that are too large being involved. Simulations are carried out and compared with several recent experimental transmission spectra in the M- and L-shell absorption regions to reveal the high accuracy of the model. The present model is also compared with the OPAL, LEDCOP and OP models for two isothermal series at T = 20 eV and T = 19.3 eV. It is found that our model is in good agreement with OPAL and LEDCOP while it has discrepancies with OP at high densities. Systematic Rosseland and Planck mean opacities in the range 10-1000 eV for temperature and 10-5-10-1 g cm-3 for density are also presented and compared with LEDCOP results, finding good agreement at lower temperatures but apparent differences at high temperatures where the L- and K-shell absorptions are dominant. © 2009. The American Astronomical Society. All rights reserved.