X-ray diffraction in double-crystal noninterferometric systems in the presence of dilatational imperfections of interplanar distances
We have studied x-ray diffraction in a system consisting of a plane-parallel crystal and a wedge-shaped crystal, having dilatational imperfections relative to each other. As a result of the difference in the interplanar distances of the reflecting planes of the crystals, the pendulum bands formed in such a system are displaced across the width of the diffracted beam. The magnitude and direction of the displacements of the pendulum bands depend on the magnitude and sign of the different distances of the reflecting planes and on the direction of incidence of the primary wave. This effect of displacement of the pendulum bands can be used to determine the sign and magnitude of the difference of interplanar dilatational imperfections of the crystals of the system.