On the problem of dynamic diffraction of X-Rays in Bragg scheme bу а crystal in which ultrasonic wave is excited.

The proЫem of dynamic X-ray diffraction according to Brag;g Ьу а crystal in which ultrasonic wave is excited has been considered. The four-wave approximation is used to oЪtain an analytical solution to the proЫem for X-ray-acoustic resonance $k_s\simeq\Delta K_0$, where k, is the ultrasonic wave vector and $\Delta K_0$ is the minimum splitting of the two-wave dispersion surface in diffraction Ьу an ideal crystal). Based on the oЪtained solution, the dependence of tbe structure of the curve of diffraction reflection on the amplitude of ultrasound has been examined.