Stopping cross sections and backscattering factors for ⁴He ions in matter Z = 1-92, E(⁴He) = 400-4000 keV

Abstract

A table is presented of semiempirical values of stopping cross sections [expressed in eV/(atom/cm2)] for 4He ions in every element (1 ≤ Z ≤ 92) for ion energies from 400 to 4000 keV. The semiempirical results have been fitted with polynomial expansions whose coefficients are also tabulated. The stopping cross sections provide parameters for the interpretation of backscattering experiments, for example factors for converting backscattering-peak widths to areal density (atoms/cm2). The semiempirical results are based on recent experimental measurements and on theoretical values calculated in the Lindhard-Winther formalism with Hartree-Fock-Slater elemental wavefunctions. Comments are included on combining the specific energy loss tables for compound backscattering analysis by using Bragg's Rule, and also on the effects on backscattering of target tilt and of the finite thicknesses of targets. © 1974.