On the treatment of saturation effects in Moessbauer spectroscopy and the evaluation of spectra

Two different methods for solving the transmission integral (TI) encountered in, e.g., Moessbauer spectroscopy are presented. In the first one the TI is approximated by a single channel calculation, while taking care of the nearby absorption cross section contributing to the absorption by comparing the cross section at the energy of the actual channel with the appropriate solution in the 'thin absorber approximation' (TAA). The method is compared with the results of TAA and of a simple 'single channel' approximation. The second method is more elaborate, aiming to be as exact as possible although not too time-consuming. The inner part of the TI is convoluted numerically whereas the outer part is calculated analytically by an asymptotic approximation. (orig.)