Non-Dipole Features of the Photon Emission Spectrum of a Fast Oriented Lepton in a Crystal

Abstract

The probability of the non-dipole emission of photons by channeled particle is calculated. The emission of hard photons with an energy comparable with that of the incident channeled particle is studied. The quasi-Bloch energy spectrum of an oriented fast charged particle entering a crystal at an angle smaller and greater than the Lindhard angle is calculated. The initial and final spectra of the channeled particle are described by different sets of band wave functions corresponding to different energies. The processes of photon generation by a quantum particle entering into the crystal at an angle larger and smaller than the Lindhard angle are considered on an equal basis. The spectrum of hard-photon emission is shown to consist of a set of well-observed emission lines.