The stopping power of solids for low-velocity channelled heavy ions

Abstract

A model of the stopping of a low-velocity heavy ion moving through an electron gas is used to calculate the stopping power of solids for channelled heavy ions. The heavy ion is considered to lose energy by transferring momentum to target electrons which scatter elastically from it, so that the stopping cross section is proportional to the momentum-transfer cross section. This cross section varies periodically with the Z1 of the incident ion, the periodicity being shown to be connected with the successive filling of atomic sub-shells of electrons. The model is applied to the stopping power of silicon for ions channelled along the (110) and (111) directions and good agreement is obtained with the data of Eisen. A feature of this approach is the reproduction of deep minima in channelled stopping power in certain regions of the periodic table.