Theorie der Ausbreitung von Röntgen-Wellenfeldstrahlen im schwach deformierten Kristallgitter

Abstract

A theory is presented for calculating the paths and the absorption of wavefield rays within a weakly deformed crystal lattice. The method of Penning and Polder⁶, suitable only for Laue-case wavefields, is extended to the most general wavefields compatible with the fundamental equations of the dynamical theory of X-ray diffraction. In the theory given here, when calculating the adaption of the wavefield to the deformation along the path of the ray, the wavefield is no longer assumed to stay on a particular branch of the dispersion surface but to form withleast spatial inhomogeneity. Formulas are developed which permit numerical calculation of the propagation of arbitrary types of wavefield rays in a given field of deformation. Any deformation may be split into pure curvature (FF) of, pure gradient of lattice parameter (NN) perpendicular to, and pure fanning out (FN) of the reflecting planes. Typical features of the effect of FF, NN, and FN are discussed for each type of deformation separately.