The theory of dynamic scattering in perfect crystals is generalized to the scattering of partially coherent X - radiation. It is shown that, both the temporal and spatial incoherences have a strong influence on the course of the p rincipal effects: extinction beats are moved and anomalous transmission (the Borrman effect) deteriorates. The method of slow amplitudes is used to obtain general results that describe the transformation of the correlation functions of a scattered X-ray beam. It is shown that the coherence radius increases on dynamic scattering (in the X-ray analog of the van Zittert-Zernicke theorem). It is found that the extinction-beat smoothing effect can be used as a basis for measurement of the correlation functions; opportunities for obtaining information on the spatial and temporal correlation functions separately are examined.
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