Schiwietz, G.; Grande, P.L.: Introducing electron capture into the Unitary-convolution-approximation energy-loss theory at low velocities. Physical Review A 84 (2011), p. 052703/1-7
10.1103/PhysRevA.84.052703

Abstract:
Recent developments in the theoretical treatment of electronic energy losses of bare and screened ions in gases are presented. Specifically, the unitary convolution-approximation (UCA) stopping-power model has proven its strengths for the determination of non-equilibrium effects for light as well as heavy projectiles at intermediate to high projectile velocities. The focus of this contribution will be on the UCA and its extension to specific projectile energies far below 100 keV/u, by considering electron-capture contributions at charge-equilibrium conditions.