Calculation of energy straggling for protons and helium ions

Abstract

Energy straggling has been calculated for protons and helium ions in each of the elements, by using the Hartree-Fock-Slater charge distribution for the target atom with Bonderup and Hvelplund's formulation. The results reveal a ${Z}_{2}$ structure in energy straggling, and afford a ready explanation of some earlier measurements.