Plasmon-diffraction resonance during motion of a fast charged particle in a single crystal

A theory is developed for the emission of bulk plasmons by a charged particle as it undergoes diffraction in a crystal. The angle-integrated cross section for inelastic scattering due to emission of a bulk plasmon by the diffracted particle is subject to a pronounced orientational effect such that for appropriate directions of motion of the fast particle conditions arise that are favorable for the emission of plasmons that have very small wave vectors and that could not be emitted as a result of the usual ''Cerenkov'' generation of plasmons. This kind of phenomenon can be called bremsstrahlung of bulk plasmons induced by the diffraction of fast charged particles. The theoretically predicted resonances in the orientation dependence of the inelastic cross section for fast particles being diffracted in a single crystal may be the basis of a method for the direct experimental observation of bremsstrahlung of longitudinal electromagnetic waves