Normale und anomale Absorption von Röntgen-Strahlen in Germanium und Silicium/Normal and anomalous absorption of X-rays in Germanium and Silicon

A brief discussion of G. Molière's generalized dynamical theory is given with respect to the interpretation of the experimental data|χ^⊥_ig/χ_i0 |obtained by means of the Borrmann effect.

In order to compare theory and experiment photoelectric absorption cross sections for Silicon and Germanium have been calculated over the X-ray energy range from 5 to 25 keV. Linear absorption coefficients measured by us and other authors agree with theory within a few per cent.

Taking the Debye-Waller factor into account, the same theoretical data have been used to calculate |χ^⊥_ig/χ_i0 | for Ge and Si. The agreement with extensive measurements of the Borrmann effect in Ge is very good in most cases. The experiments presented in this paper confirm the existence of the electric quadrupole transitions within the photoelectric effect.