Dynamics of high-energy charged particles in straight and bent crystals

The problems of the dynamics of high-energy charged particles in straight and bent crystals are discussed. Various methods for describing particle scattering in crystals are considered, including the Born approximation, classical electrodynamics, and the eikonal approximation. These problems belong to the theory of nonlinear systems in which both regular and chaotic motion is possible. Various types of chennelling motion and above-barrier motion of particles in crystal along one of the crystallographic axes are discussed. Special attention is given to the studies of motion of particles in a bent crystal, which may be used to bend high-energy particle beams.