K-shell ionisation cross sections for Ti, Fe, Cu, Zr and Ag by protons and He ions in the energy range 85-790 keV

Abstract

Absolute K-shell ionisation cross sections have been measured for thin targets of Ti, Fe, Cu, Zr and Ag for protons in the energy range 85-790 keV and for thin targets of Ti, Fe and Cu for He ions in the energy range 190-750 keV. In addition the relative variation of the cross sections with energy has been determined with high accuracy. The experimental values are compared to the perturbed stationary state approximation (CPSSR) and the semiclassical approximation (SCA). The CPSSR theory provides the best overall agreement with experimental cross sections. For higher scaled energies y= eta /( zeta theta )2 the CPSSR theory predicts the energy dependence of the cross sections very well but in the lower energy range it overpredicts the cross sections by as much as a factor of two and this overprediction seems to increase with Z2 at a fixed scaled energy y. The SCA theory predicts slightly too large ionisation cross sections except for the lowest xi values. The relative variation of the cross sections with energy is not well described in either energy range.