MULTIPLE-CENTER EFFECTS IN THE STOPPING POWER OF SLOW CLUSTERS

The stopping power of a slow cluster in an electron gas is studied under the standard assumption that the potentials of its constituents do not overlap. As an example, an isotropic approximation of the scattering amplitude for the collision of the electrons with the atoms in the cluster is employed, and the importance of multiple-center scattering events is analysed. Low-order multiple-scattering effects are shown to be comparable in magnitude to the simple interference mechanism. Therefore these terms cannot be neglected in an accurate evaluation of the vicinage function.