Stochastic model of ultrarelativistic electrons passage through a thick monocrystals

The model of electron dynamics is suggested for the high-energy beam passing through crystal, taking into account axial channeling, multiple scattering and radiation. The model represents homogenous Markov process with diffusion and jump components, described by a stochastic differential equation. Here diffusion corresponds to dissipation and jumps correspond to radiation of $\gamma$-quanta. This description is convenient for numerical calculations not only for passage but for other physical characteristics that are functional of Markov process paths, in particular for characteristics of radiation.