The stopping power of an ensemble of a large number of fast heavy ions, moving in a plasma, with a distribution function which has small spreads both in the physical and in the velocity spaces, is computed on the basis of a classical dielectric theory, retaining two-ion correlation effects. Averaging procedures in the configuration space are used to determine the actual friction force acting on the whole system and to evaluate the vicinage effects when the ion beam is not strictly monochromatic, as it was considered previously. Approximate analytical scalings with the physical parameters of the considered system of the average vicinage function and of the decorrelation time are given.

• Received 26 September 1994

DOI:https://doi.org/10.1103/PhysRevE.51.R2755