Dechanneling of High-Energy Particles from Planar Channels of Crystal. Elastic and Inelastic Scattering Processes

Abstract

On the basis of the principles of nonequilibrium statistical thermodynamics, the kinetic theory of dechanneling of high-energy particles from planar channels of a crystal has been deduced. The dechanneling rate coefficient is considered from the point of view of the transition of a fast particle from the directional motion mode to the state of chaotic motion. The corresponding equation has been obtained that takes into account both the coherent nature of the diffraction of a particle beam in a regular single crystal and the inelastic scattering of channeled particles by electrons and phonons. An analytical solution of this equation has been obtained on the class of confluent hypergeometric function with the use of which the dechanneling rate constant R_e has been calculated. It has been shown that, up to second-order terms in terms of the interaction potential, the constant R_e is inversely proportional to the relaxation time of the system τ_ph. In calculating τ_ph, the polarization of space by a fast charged particle is not taken into account. The temperature and isotopic dependences of the dechanneling rate have been obtained.