A strict dynamical theory of radiation scattering in defect crystals is developed involving no arbitrary assumptions. Final theoretical expressions are obtained for the case of Laue‐diffraction in monocrystals containing homogeneously distributed defects, in particular Coulomb‐like defects (clusters, dislocation loops). The theory gives an unified description of the thickness dependences of intensity scattering both, for thin and thick crystals, and predicts an effect of anomalous transmission of diffuse background in thick crystals. Experimental investigations on O‐ or Cu‐doped Si‐monocrystals are carried out which confirms the theory.

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A method is developed for the discrimination of the diffuse scattering absorption coefficient μDS from the experimental interference absorption coefficient (IAC) μie by the investigation of the dynamical scattering of X‐rays for wavelengths near the K absorption edges of Ga and As in GaAs crystals heavily doped with Te. Conclusions are made about the appearance of dislocation loops after the Te solid solution decay comparing the IAC increments ratios measured at different hkl reflections for Cuα and CuKβ radiations and those values calculated by means of formulae obtained from Dederichs's theory for μDS. The conclusions of this theory are experimentally proved with the dependences of μDS on the wavelength λ and diffraction vector H.

The instrumental effect on the measured Laue‐diffracted intensities is theoretically studied for a single‐crystal spectrometer (SCS). The calculated parameters A and B entering the relation In S  A t + B between the logarithm of intensity jumps (S  i2/i1) and the crystal thickness are in agreement with those measured near the absorption K‐edges of Ga and As at different reflections (hkl). The influence of wave fields with different polarizations on these parameters is also considered. It is shown both theoretically and experimentally that at a transition from (III) to (III) Laue reflections the quantity A which corresponds to absorption processes, is unchanged while the parameter B describes the intensity jumps fairly well.