https://doi.org/10.1051/epjconf/20135914004
Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV
1 ARTEP Ellicott City, MD 21042, USA
2 CEA/IRFU/Sap, 91191 Gif-sur-Yvette Cedex, France
a e-mail: busquet@artepinc.com
Published online: 15 November 2013
Opacity is a fundamental ingredient for the secular evolution of stars. The calculation of the stellar plasma absorption coefficients is complex due to the composition of these plasmas, generally an H /He dominated mixture with a low concentration of partially ionized heavy ions (the iron group). The international collaboration OPAC recently presented extensive comparisons of spectral opacities of iron and nickel for temperatures between 15 and 40 eV and for densities of ∼ 3 mg/cm3, relevant to the stellar envelope conditions [1, 2]. The role of Configuration Interaction (CI) and the influence of the number of atomic levels on the opacity using the recently improved version of HULLAC atomic code [3, 4] are illustrated in this article. Comparisons with theoretical predictions already presented in [1] are discussed.
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
