Energy loss of axially channeled antiprotons

Abstract

A detailed study of energy spectra (channeled fraction, most probable energy loss, shape of the spectra) of low energy antiprotons moving in a thin crystal, under axial channeling conditions is performed using a Monte Carlo computer simulation. The results of calculations for antiprotons are compared with those for protons. It was observed that the channeled fraction of the antiproton beam is considerably smaller than that for protons due to strong dechanneling. This fraction as a function of incident angle shows a maximum at angles near ψ = 0.5 ψ L. Whereas for protons, well aligned with a crystal axis, the energy loss is onsiderably reduced as compared to the random beam, for antiprotons the energy loss is nearly the same as for those in a random direction. The spectra for antiprotons are wider than those for protons and have a high-loss tail. In general the directional effects in energy spectra are less pronounced for antiprotons than for protons.