Abstract

The formalism of the optical coherence has been applied to the description of the Bragg-case dynamical X-ray diffraction from crystals with randomly distributed amorphous spheres. Explicit formulas have been found for the reflection curves of such crystals in the first and second approximations of the iterative solution of the Takagi equations. It is shown that if the coherent plane wave falls on the crystal the diffracted wave consists of two parts - the plane coherent wave (which corresponds to the diffraction from a perfect crystal with a modified value of the Debye-Waller factor) and the partially coherent wave (diffusion scattering). The form of the partially coherent contribution to the reflection curve is discussed and its dependence on the defect diameter and the defect concentration. From the curves the integrated intensities are obtained. It is proved that the integrated intensity of the waves diffracted from such crystals depends linearly on the relative disturbed volume of the crystal and in the first approximation it does not depend on the defect diameter if this volume remains constant.