Proton dechannelling in Ge probes the crystal scattering

Abstract

The present work reports a set of experimental data on proton dechannelling in Ge; the general features of these results are similar to those reported for Si though some quantitative differences appear according to the crystal nature. The available experimental data enabled us to carry out a detailed discussion of the approximations involved in dechannelling theory and in calculations. Some emphasis is given to the influence of the potential used to describe the ion-target interaction; significant differences rise on going from the T.F. (Moliere) to the Lindhard's standard potential. Remarks are also made on the description of the moving ion interaction with the core and valence electrons, as it concerns multiple scattering. The importance of the ion beam diffusion because of multiple electronic and nuclear scatterings, so far neglected, has been evaluated to be, except at large value of the dechannelled fraction, a small correction to the steady-increase description.