A reduced mathematical model for the transport of high current relativistic electron beams in a dense collisional plasma is developed. Based on the hypothesis that the density of relativistic electrons is much less than the plasma density and their energy is much higher than the plasma temperature, a model with two energy scales is proposed, where the beam and plasma electrons are considered as two coupled sub-systems, which exchange the energy and particles due to collisions. The process of energy exchange is described in the Fokker-Planck approximation, where the pitch angle electron-ion and electron-electron collisions dominate. The process of particle exchange between populations, leading to the production of secondary energetic electrons, is described with a Boltzmann term. The electron-electron collisions with small impact parameters make an important contribution in the overall dynamics of the beam electrons.

This paper presents theoretical results for the influence of plasma electron-electron collisions in correlated proton stopping forces. First calculations of the effects of these collisions on the vicinage forces for plasma matter are shown. In particular, these effects are studied in a Te = 10 eV and n = 1023 cm−3 plasma yielding a self-retarding proton force increased more than 11% at maximum value. Also vicinage forces enhances more than 15% in the analyzed cases. All this implies that plasma electron-electron collisions play an important role both in non and correlated ion stopping and must be considered for any application of ion energy deposition in plasma matter.