Cascade processes of energy loss by emission of hard phonons

The method of cascade equations is used for studying the dynamics of the energy loss process (struggling) during passage of particles through a substance. Special attention is paid to multiphoton processes of emission of relativistic electrons in amorphous media and in oriented crystals. New analytic solutions to cascade equations are obtained and a method is developed for solving these equations, which makes it possible to express the results in terms of rapidly converging integrals. It is shown that the relatively simple Landau equation for the energy loss distribution function can be used for analyzing processes of energy loss commensurate with the initial energy of particles. The experimental data for 150-GeV electrons in oriented crystals are thoroughly analyzed.