The manifestation of the band structure in the photon emission spectrum of the fast above-barrier oriented particle

TL;DR

This paper investigates the photon emission spectrum of fast, oriented particles in crystals, revealing that non-dipole hard photon emission exhibits distinct spectral lines and is experimentally observable, with implications for understanding quantum crystal interactions.

Contribution

It provides a detailed calculation of the quasi-Bloch energy spectrum and demonstrates the observable spectral lines in non-dipole hard photon emission from channeled particles.

Findings

Emission spectrum contains well-defined lines.

Nondipole photon radiation probability is significant.

Hard photon emission is experimentally detectable.

Abstract

The probability of emission of photons in non-dipole case by channeled particle is calculated. The emission of hard photons with an energy comparable to the energy of the incident channeled particle is examined. The calculation of the quasi-Bloch energy spectrum of the oriented fast charged particle entering the crystal at an angle substantially greater than the Lindhard angle is performed. The initial and final spectra of the channeled particle belonging to a different set of band wave functions corresponding to different energies are used. The processes of the photon generation by the quantum crystal-oriented particle entering into the crystal at an angle both greater and smaller than the Lindhard angle are considered on the equal footing. It is shown that the spectrum of hard photon emission consists of a set of the well-observed emission lines. The probability of the nondipole photon radiation by the channeled particle with the energy within a small solid angle oriented along the propagation direction of the channeling particle is shown to be equal to It has been shown that the nondipole processes of the radiation of hard photons by the channeled particles are well observed experimentally.