Resonant influence of a longitudinal hypersonic field on the radiation from channeled electrons

The wave function of a planar/axially channeled electron with energy 10 MeV less than or equal to E much less than 1 GeV under the influence of a long itudinal hypersonic wave excited in a single crystal is calculated. Conditi ons for the resonant influence of the hypersonic wave on the quantum state of the channeled electron are deduced. Expressions for the wave function th at are applicable in the case of resonance are obtained. Angular and spectral distributions of the radiation intensity from the plan ar/axially channeled electron are also calculated. The possibility of signi ficant amplification of channeling radiation by a hypersonic wave is substa ntiated. It is found that the hypersound can excite inverse radiative trans itions through which the transversal energy of the channeled electron is in creased. These transitions have a resonant nature and can lead to a conside rable intensification of the electron channeling radiation. In the case of axial channeling, the resonance radiation is sustained also by direct radia tive transitions of the electron. (C) 2001 Elsevier Science B.V. All rights reserved.