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A method is described for computing the Rosseland and Planck mean opacities of an element as a function of temperature and density. The method is based on the average ion representation for calculating the occupation numbers of the various electronic levels. The photoabsorption coefficients are calculated in the hydrogenic approximation. To account for the important contribution of line absorption, a simple phenomenological method has been developed, which takes into consideration effects such as broadening of the upper electronic levels into bands and band overlapping in the heaviest of the elements. Calculations are presented for various elements and compared with the results of more elaborate methods. Power-law scaling relations for the dependence on temperature and density are derived for a number of elements of practical importance.

Additional information

Authors: TSAKIRIS G D, Max-Planck-Institut für Quantenoptik, Garching bei München (DE);EIDMANN K, Max-Planck-Institut für Quantenoptik, Garching bei München (DE)
Bibliographic Reference: Article: Journal of Quantitative Spectroscopy and Radioactive Transfer, Vol. 38 (1987), No. 5, pp. 353-368
Record Number: 198910687 / Last updated on: 1994-12-01
Original language: en
Available languages: en
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