Spectrally resolved and Rosseland and Planck mean opacities of iron plasmas at temperatures above100eV: A systematic study

Abstract

The radiative opacity of iron plasmas at high temperatures is very important in astrophysics. The spectrally resolved radiative opacity and Rosseland and Planck means were investigated by using the detailed-level-accounting (DLA) model for iron plasmas at high temperatures and a variety of density. The accuracy of atomic data such as energy levels and transition probabilities is checked by comparison with data from the National Institute of Standards and Technology. The transmission of iron plasma at a temperature of 156 eV and an electron density of 6.9 x 10(21) cm(-3) is studied in detail and compared with results of a recent experiment [Bailey et al., Phys. Rev. Lett. 99, 265002 (2007)] and other theoretical results. General good agreement is found between our DLA transmission and the experimental and other theoretical results. By using our developed DLA model, we can deduce valuable information on the physical condition of the plasma created in the experiment. The information includes the fractional distribution of different ion stages and whether the plasma is in local thermodynamic equilibrium or not. Illustrative results are given for three isothermal sequences of 100, 150, and 200 eV with different mass densities and for three isodensity sequences of 0.1, 0.05, and 0.01 g/cm3 with different temperatures. The Rosseland and Planck mean opacities are compared with other theoretical results obtained by the Los Alamos light element detailed configuration opacity code.