Influence of ultrarelativistic electron beam divergence on spectral-angular characteristics of coherent X-radiation generated in a single-crystal target

A dynamical theory of coherent X-ray radiation generated in a single-crystal target by the finite divergence beam of relativistic electrons has been developed in the scattering Laue geometry. Coherent X-ray emission is considered in general case of asymmetric reflection for electron Coulomb field in the form of two emission mechanism contributions: parametric X-ray radiation (PXR) and diffracted transition radiation (DTR). The method of averaging radiation cross section over the angular electrons distribution is used. The influence of electron beam divergence on both spectral and angular characteristics of coherent radiation has been studied. The significant difference of the effects of electron beam divergence in PXR and DTR is shown. The possibilities of practical use of DTR from a single-crystal target for indication of beam divergence of ultrarelativistic electrons are investigated.