X-ray radiation generated by a beam of relativistic electrons in composite structure

The dynamic theory of coherent X-ray radiation generated by a beam of relativistic electrons in the three-layer structure consisting of an amorphous layer, a vacuum (air) layer and a single crystal has been developed. The phenomenon description is based on two main radiation mechanisms, namely, parametric X-ray radiation (PXR) and diffracted transition radiation (DTR). The possibility to increase the spectral-angular density of DTR under the condition of constructive interference of the transition radiation waves from different boundaries of such a structure has been demonstrated. It is shown that little changes in the layers thicknesses should not cause a considerable change in the interference picture, for example, the transition of constructive interference into destructive one. It means that in the considered process the conditions of constructive interference are enough stable to use them for increasing the intensity of X-ray source that can be created based on the interaction of relativistic electrons with such a structure.