A simple method for calculating X-ray absorption spectra for use in crystal spectrometer and mirror analysis

A simple scheme is described whereby x-ray absorption spectra, including the very strong rapidly varying structure near an absorption edge, may be calculated using only a short program and small amounts of computer time. The analysis also provides general rules for the existence of strong structures at the edge. The scheme can describe any neutral absorbing atom (or, with a little modification, ion) and includes the effect of the core hole when necessary. Fits to experiment show good agreement near absorption edges, with somewhat poorer agreement far from the edge. The method is of use in obtaining absorption spectra for use in crystal spectrometers for x-ray mirror calculations where a knowledge of the fine detail of the absorption is not necessary, but an accurate reproduction of the major structure near the edge is. (author)