Dechanneling and modification of particle distribution induced by lattice defects

The diffusion equation is applied to obtain the particle distribution in the transverse energy for channels containing lattice defects and the dechanneling caused by lattice defects is calculated. It is found that the particle distribution is considerably modified by lattice defects and that this modification of distribution enhances the dechanneling through electronic and nuclear collisions. The results obtained with the present method (referred as diffusion model) are compared with those obtained with the various other models, such as single, plural and multiple scattering models. It is shown that the single scattering and multiple scattering models account for the result of the diffusion model only for small and large surface concentration of defects, respectively. And then, it is concluded that the diffusion model is the most appropriate method in the intermediate region. (auth.)