X-ray transition radiation energy loss of relativistic charge in absorbing media

The theory of X-ray transition radiation is generalised to the case of absorbing media. The energy-angle distributions of the mean number of X-ray transition radiation photons produced by a relativistic charged particle crossing an interface between absorbing media are derived for different geometries. The models describing different practical radiators are implemented in the framework of the GEANT4 package. The calculations are in satisfactory agreement with experimental data for the energy loss distributions measured in gaseous proportional detectors. (23 refs).