Stopping power of Ni, Ag, Au, and Pb for ∼7-MeV/nucleonαparticles and carbon ions:Z13deviation from the Bethe formula

Abstract

The stopping powers of Ni, Ag, Au, and Pb for approx.7-MeV/N (where N means nucleon) C ions and ..cap alpha.. particles have been measured. For the 7.00-MeV/N C ion, the stopping powers of Ni, Ag, Au, and Pb are found to be 1.353 +- 0.016, 1.080 +- 0.010, 0.832 +- 0.006, and 0.825 +- 0.006 MeV/mg cm/sup 2/, respectively. From these results, the Z/sub 1//sup 3/ deviation from the Bethe-Bloch formula is evaluated comparing with our experimental stopping power for ..cap alpha.. particles. In the course of analysis we employed appropriate effective-charge corrections. Pierce and Blann's effective-charge correction, e.g., gives a reasonable value (1.38) of the b which appears in the Ritchie-Brandt theory, if a chi value of 1.29 in their theory is assumed.