UV and X-ray diffraction and transition radiation from charged particles bunches

Diffraction and transition radiation from a bunch of relativistic charged particles in the X-ray frequencies range is considered. The spectral and angular distribution of the emitted energy is obtained. The coherence effects are proved to be important up to wavelengths much less than transversal size of the bunch. It is shown that the incoherent part of the form factor both for transition and diffraction radiation exists and differs from the unity. It is shown also that the form factor for transition radiation depends on the properties of the target material in case particles trajectory crosses the target near its edge.