Differences in the energy loss of protons and positive muons in solids

We evaluate the magnitude of the difference in the electronic energy loss of positive muons and protons in solids in the low-energy range using both the dielectric formalism and the non-linear transport cross-section (TCS) method. The effects of mass increase at low energies, showing stopping differences between 5% and 1% for velocities in the range 0.2 < <nu> < 1 a.u. We find that nuclear stopping effects must also be taken into account for a consistent analysis in the low-energy range. (C) 2001 Elsevier Science B.V. All rights reserved.