Theory of channeling at small depths. II.

The paper presents an approximate solution of the Focker-Planck kinetic equation with an allowance for the unharmonic potential. This solution is obtained by using asymptotic methods of non-linear mechanics. It is shown that the perturbation theory method is inapplicable for this problem. The solution obtained is used to calculate the relative flux in planar and axial channels. The theory developed in this paper may be used to interpret experiments on determining the location of an impurity atom in a lattice. [ABSTRACT FROM PUBLISHER]