Kyryllin I. Orientation effects in the passage of relativіstic charged particles through bent crystals

The Doctoral Thesis presents the theory and methods of simulation of orientation effects in bent crystals. The dependence of the probability of close collisions of both positively and negatively charged relativistic particles with atoms in a bent crystal on the angle between the initial momentum of the particles and the plane of bending of the crystal is found. A method for finding optimal conditions for the effective deflection of negatively charged particles in a bent crystal is proposed. The theoretical description of the stochastic mechanism of deflection and planar channeling in case of particle motion in a bent crystal taking into account incoherent scattering is generalized. A method for splitting a beam of relativistic positively charged particles into several beams during the passage of a beam of particles through a bent crystal under conditions of realization of a stochastic deflection mechanism is proposed and optimal conditions for such splitting are found. The spectra of ionization energy loss of fast negatively charged particles during planar channeling in a straight and bent crystal are obtained and the connection between the characteristics of these spectra and the dechanneling length of charged particles in the crystal is found. The theoretical description of the radiation of channeling particles is generalized to the case of angles between the momentum of particles and atomic strings, at which local maxima in the radiation spectrum associated with scattering on individual atomic strings become noticeable. The theoretical analysis developed in the dissertation allows to deepen the idea of the processes that take place during the motion of relativistic charged particles in bent crystals, and the results of research can be used both for setting up new experiments and for using bent crystals to derive beams from accelerators, splitting of beams into several parts, changes in the shape of beams at short distances, deflection of short-lived particles and generation of electromagnetic radiation in a wide frequency range.