Higher order Z1 effects in heavy ion stopping powers and ranges

Abstract We have measured the ranges of energetic ( E 1 ⩽ 2.5 MeV/amu) heavy ions ( Z 1 = 14, 28, 79) in thick targets ( Z 2 = 29, 47, 82). The results suggest modification of current stopping power compilations. Two effects are seen, including (1) nonlinearity of stopping power vs. velocity at low velocity, and (2) changes in the location and the magnitude of the stopping power maximum. Independent thin target d E d x measurements confirm these results. The low velocity effects are reasonably well described by the calculations of Ziegler, while inclusion of higher order ( Z 1 3 , Z 1 4 ) corrections to the Bethe formula allow accurate fits to the data near the stopping power maximum.