Bethe-Bloch stopping power parameters for Al, Cu, and Ag extracted from recent accurate measurements

Accurate measurements of the stopping powers of Al, Cu, Ag, and Au for protons, α particles, and Li ions have been analyzed to extract values of mean excitation energy (I) and Barkas-effect parameter (b) for each target material. Two versions of shell corrections were employed, with only one yielding consistent, plausible results. Recommended values of I and b for Al, Cu, and Ag are, respectively, 165 ± 3 eV and 1.37 ± 0.05, 329 ± 4 eV and 1.36 ± 0.06, and 483 ± 5 eV and 1.30 ± 0.07.