The energy loss of a pair of charges in correlated motion through an electron gas is calculated using Lindhard's dielectric function. The results of numerical integrations are presented and in particular the cases of low and high velocities are described. Analytical expressions for the energy loss are given for the case of high velocities, which are in excellent agreement with the numerical results. A clear relationship between the energy loss of fast correlated charges and the partition rule for the stopping does not follow from this study. The results are in agreement with experimental data for the energy-loss ratio between molecular and atomic ions in thin carbon foils.

• Received 24 May 1977

DOI:https://doi.org/10.1103/PhysRevB.18.1