Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1684211 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2010 | 5 Pages |
Energy losses of protons and alpha particles in silver have been accurately measured under the same experimental conditions over the velocity range Elab=(0.192–2.595)Elab=(0.192–2.595) MeV/amu using the transmission method. Deduced S(E)S(E) stopping powers are compared to most accurate ones from the literature, to values generated by the SRIM-2008 computer code and to ICRU-49 compilation. They were analyzed in the framework of modified Bethe–Bloch theory for extracting Ag target mean excitation and ionization potential, I, and Barkas effect parameter, b . Values of (466±5466±5) eV and 1.20±0.011.20±0.01 for these two parameters were inferred from the proton S(E)S(E) data while the alpha particle data yielded values of (438±4)(438±4) eV and 1.38±0.011.38±0.01, respectively. The (I, b) stopping parameters thus exhibit opposite variations as the projectile charge increases, similarly as we have found previously for nickel [6]. This can be ascribed only to an effect of the projectile electronic structure at low velocities. The obtained results are discussed in comparison to previous ones reported in the literature.