Dependence of X-ray asymmetrical Bragg case plane-wave rocking curves on the deviation from exact Bragg orientation in and perpendicular to the diffraction plane

Abstract

For the asymmetrical Bragg case the X-ray plane-wave reflection coefficients and rocking-curve dependences on the deviation angles from the exact Bragg orientation in the diffraction plane and in the direction perpendicular to the diffraction plane are analysed. The region of total reflection and its size dependence on two deviation angles are analysed as well. New peculiarities of the rocking curves are obtained.

X-ray microbeam diffraction in a crystal

“…It is assumed that along the y coordinate, perpendicular to the diffraction plane (x, z), the X-ray field is homogeneous and integrated over the y coordinate. Usually, the dependence of the X-ray field in three coordinates (x, y, z) is considered within the framework of diffraction studies, taking into account the deviation of the angles from the exact Bragg orientation in the diffraction plane and in the direction perpendicular to the diffraction plane (Balyan, 2019), or in the case of diffraction in a crystal with 3D defects (Nesterets & Punegov, 2000). Note that in the case under consideration, in the system of equations (1), we cannot neglect the derivative with respect to the x coordinate, since both the incident and reflected waves are spatially restricted in this direction.…”