Semiclassical approach to channeling and dechanneling

Publisher Website
Google Scholar
Abstract
Dechanneling, i.e. the transition of energetic charged particles from the aligned to the random beam in crystals, is mainly caused by two processes, namely scattering by nuclei and by electrons. In this paper the scattering of the channeled particle by the lattice nuclei is analysed using the transfer matrix treatment and in particular the escape of the particle from the channel through the potential barrier produced by the lattice atoms is considered for the one dimensional planar case. Accordingly the dechanneling fraction is calculated using the WKB method with the wave function of the planar channeled particle written in this approximation. The result of calculations using this model for dechanneling in diamond-type lattices (Si and Ge) are compared with experimental data and good agreement is seen for the dechanneling curves and critical angles. However the calculated dechanneling rates are in general lower and this is attributed to the electronic contribution to the dechanneling being neglected.