Concerning transition radiation by a relativistic electron in a thin metallic plate

The influence of transverse target's size on the transition radiation spectrum of a relativistic electron moving through the thin metallic plate is considered. It has been shown that significant spectrum distortion can occur in the millimeter range of waves in comparison to the case of an infinite metallic plate. This effect takes place for "forward" and "backward" radiation in both cases, i.e. for normal incidence of electron on the target as well as for oblique incidence.