Stopping powers of solids for 84,86Kr, 100Mo and 129,132Xe ions at intermediate energies (20–45 MeV/u) and the charge state distributions at equilibrium

Abstract

The stopping powers of ten solid media (nine elements from Be to Au and mylar) have been measured for 25–45 MeV/u Kr and 25 MeV/u Mo and Xe ions. The accuracy in stopping power determinations is ± 1–2%. In addition, the charge state distributions at equilibrium of Kr, Mo, Xe ions exiting Be, Al and Au targets have been determined. Average charge states Q ̄ have been deduced. For Kr ions exiting any target, a semi-empirical expression has been obtained to predict the mean charge Q ̄ in a large energy domain (4–50 MeVu). The stopping power data have been compared with a scaling relative to He 2+ ion stopping powers, assuming fully stripped ions inside the degraders. Effective charge parameters γ have been derived and compared with the ionization degree Q ̄ /Z 1 . Information concerning the emission of Auger electrons by ions exiting targets has been obtained. The stopping power data have also been compared with values from Ziegler (1980). Discrepancies are observed for light (Be) and heavy media (Ta-Au). A comparison has been made with the very recent semi-empirical calculations from Hubert et al. (1989). Excellent agreement is found with experimental data for all projectiles and media.