Multiphoton processes in radiation of relativistic electrons in oriented crystals

The number of bremsstrahlung photons and the resulting energy loss for an e lectron passing through a crystal are random quantities. The kinetic equati on for the energy loss distribution has been derived and transformed into t he equations for the distributions moments. The equations for the moments h ave been solved in continuous slowing down approximation using full screeni ng Bethe-Heitler formulas for incoherent bremsstrahlung cross-sections and simple phenomenological expressions for coherent bremsstrahlung and channel ing radiation. The solutions were used to calculate the number of "coherent " photons per unit path length and the mean energy of a photon. They were e xpressed in terms of the moments of energy loss distribution which can be d etermined experimentally. The results are compared with the data of other a uthors. (C) 2001 Elsevier Science B.V. All rights reserved.