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Computer Simulations of X‐Ray Spherical Wave Laue Diffraction in a Thick Perfect Crystal with a Triangular Cutout on the Exit Surface
Author(s) -
Kohn Victor Germanovich,
Smirnova Irina A.
Publication year - 2020
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201900441
Subject(s) - diffraction , crystal (programming language) , intensity (physics) , perfect crystal , physics , fourier transform , optics , diffraction topography , fast fourier transform , surface (topology) , geometry , bragg's law , condensed matter physics , mathematics , algorithm , quantum mechanics , computer science , vacancy defect , programming language
The results of computer simulations of X‐ray spherical wave dynamical Laue diffraction in a perfect crystal of a special shape are presented. Namely, the crystal has a triangular cutout on the exit surface with the angle 2 θ less than 2 θ B , where θ B is the Bragg angle. The effect of a strong increase in the intensity near the triangular cutout is found in the case of a thick crystal. It is demonstrated that the X‐ray beam intensity can be increased up to seven times under the conditions of the Borrmann effect. The fast Fourier transform (FFT) algorithm is used at the first step where simulations of spherical wave Laue diffraction in a perfect crystal slab are performed. Thus, the X‐ray fields are obtained in front of the triangular cutout which are used as boundary conditions for the second step. At the second step, a direct numerical solution of the Takagi equations is used. The effect of a strong increase in intensity is observed for all source‐to‐crystal distances including the distance of diffraction focusing. This effect is explained in terms of a crystal propagator.