Stopping power of a finite-temperature electron gas for slow unit charges

The stopping power of protons and antiprotons moving at low velocities through a uniform temperature-dependent electron gas is calculated by making use of the momentum-transfer cross section. The screened scattering potential required is determined with the aid of a parametric dielectric function obtained from the linearized Thomas–Fermi–von Weizsäcker treatment for screening in extended systems. A nonperturbative constraint, provided by the nuclear-cusp condition for the total electron density at the position of the probe charge, is used to fix the parameter value. The temperature-dependent higher-order effect on the stopping power is discussed for metallic densities of the system, showing that first-order approximations are valid only asymptotically.