Nonlinear stopping power and energy-loss straggling of an interacting electron gas for slow ions

Theoretical calculations of the basic quantities that characterize the stopping of an interacting electron gas for slow ions are presented. An appropriate low-frequency expansion for the imaginary part of the density response function has been used to modify well-known results for the noninteracting electron gas. The inner dissipative nature of the elementary electron-hole excitation is characterized by a complex local-field correction function. The basic quantities are expressed in terms of the phase shifts determined from a nonlinear density-functional formalism.