The dynamical theory of diffraction in a crystal modulated by a surface acoustic wave in the case of spatially restricted X-ray beams

The dynamical theory of X-ray diffraction in a crystal modulated by a surface acoustic wave (SAW) is developed for spatially restricted beams. It is shown that this approach is applicable to X-ray reciprocal space mapping. Rayleigh's surface-wave model is used to describe ultrasonic excitation. Based on the recurrent relations, a numerical simulation of the dynamical diffraction in a crystal modulated by a SAW is performed. Within the framework of the triple-axis diffraction scheme, the effect of the instrumental function on X-ray diffraction data is studied.