Spatial coherence in transition radiation from short electron bunches

The characteristics of coherent transition radiation that is generated by a “disk-shaped” electron bunch inclined with respect to the direction of its propagation have been considered. It has been shown that the angular distribution of transition radiation becomes asymmetric because of spatial coherence. For angles of inclination much larger than the characteristic emission angle equal to the inverse Lorentz factor, the angular distribution for wavelengths comparable to the longitudinal size of the bunch has a single maximum. In this case, the maximum of the yield of coherent transition radiation coincides with the inclination angle of the bunch.