Energy-loss and straggling of hydrogen and helium ions in silver

Abstract Energy-loss and straggling of protons, deuterons and 4 He ions in silver were measured in the energy range between 0.14 MeV and 2.6 MeV. For energies between 0.25 and 0.60 MeV/amu the stopping powers of the hydrogen ions in silver are up to 10% lower than the semi-empirical values of Andersen and Ziegler. Better agreement is obtained with the shell-correction fit for energies above 0.6 MeV/amu. In the case of the helium ions the measured values are between 8% to 13% lower than the semi-empirical values of Ziegler. The reduced straggling for the 4 He and hydrogen ions is energy independent above 0.3 MeV/amu with the He values the same as predicted by the Bohr estimate but the hydrogen values are about 15% lower.