Stopping Power of Al, Cu, Ag, Au, Pb, and U for 5-18-MeV Protons and Deuterons

High energy protons and deuterons of energies between 9 and 18 MeV have been used to extend earlier measurements of the stopping power of Al, Cu, Ag and Au and the stopping powers of Pb and U in the range 5-18 MeV have been determined for the first time. Mean excitation potentials have been determined for all materials studied and the value for Cu is found to be 319.8±3.2 eV, in agreement with the previous determination by the same authors, but the deduced mean excitation potentials are lower than those calculated by 5-10%. The relationship between mean excitation potential and atomic number is consistent with an oscillatory function roughly following the periodic system of the elements.