Statistical theory of rapid particles channelling based on the local Boltzmann equation. Correlation matrix of interactions and diffusion function of particles

Based on Bogoliubov's chain of equations the kinetic theory of rapid particles in crystal is developed. For one-particle distribution function under iteraction of particles with thermal oscillations and valent electrons a local kinetic equation is obtained. With the account of the explicit form of the collision term in the kinetic equation the basic characteristic of a subsystem of particles in the dechannelling problem – diffusion function $B(\varepsilon_\perp)$ in the space of transversal energies is found. It is shown that the functional dependence provided by $B(\varepsilon_\perp)$ is different in three regions of $\varepsilon_\perp$, corresponding to channelling, quasichannelling and chaotic motion of particles. It is also shown that the diffusion function has a break when the transversal energy equals to the top of the potential barrier of a channel.