The theory of synchrotron radiation limited beams diffraction in single crystal in the Laue case

The features of the Bragg diffraction of coherent synchrotron radiation on the atomic lattice of a single crystal in the Laue geometry are studied theoretically, provided that the radiation beam is limited by a relatively large slit placed in front of the crystal. The method of numerical simulation is used and dependences of the intensity distribution are obtained for various thicknesses of the crystal. It is shown that the slit edges introduce inhomogeneous intensity distortions inside the Bormann triangles with an angle of 2θB, where θB is the Bragg angle. In the area where the triangles intersect, the intensity distribution is similar to that for diffraction by a slit in air at a certain (large) distance. An equation for the correspondence between the distance and the thickness of the crystal is obtained, which describes well the results of numerical calculations.