An experimental study of stopping power for MeV heavy ions

A 60 MeV Ag primary ion beam was used to generate secondary recoil ion beam s of Cl, K, Ca, Sc, Ti, V,Mn and Cu in the energy range 0.1-0.6 MeV n(-1). The stopping power in the carbon absorber was measured and compared with Li ndhard, Scharff and Schiott (LSS) theory, the Northcliffe and Schilling mod el and semiempirical estimates of Ziegler er al (1985). Data for heavier io ns of Ag, I and Au from other sources was also considered in order to exten d the scope of such a comparison. LSS theory was found to satisfy the data within a narrow mid-velocity range (similar to 0.6-0.8v(0) Z(1)(2/3), where v(0) is Bohr velocity). Estimates made by Ziegler et al were seen to gener ally agree to within a few per cent except for energies below 0.2 MeV n(-1) , where deviations as high as 25% were seen. Expected Z(1) oscillations cou ld not be discerned down to the lowest ion velocities (v = 2v(0)) so far at tempted.