Measurement of M X-ray production cross sections in gold by proton, oxygen and nickel ion impact

Abstract

Measurements of M-shell X-ray production cross sections in Au with proton, O 5+- and Ni 5+-ion impact have been performed. The energy of the incident protons range from 1 to 5 MeV, oxygen ions from 66 to 72 MeV and nickel ions from 58 to 87 MeV. The experimental results have been compared with the predictions of the plane wave Born approximation (PWBA) and the perturbed stationary state theory with energy loss, Coulomb deflection and relativistic corrections (ECPSSR). For proton impact the measured cross sections have been found to be in good agreement with both these theories. With O-ion impact the ECPSSR theory underpredicts the experimental data while the PWBA agrees fairly well. Both the theories, however, strongly underestimate the X-ray cross sections measured with Ni-ion impact. The discrepancy between the experimentally measured and theoretically calculated cross sections in case of heavy ion impact could be due to multiple ionization which changes the values of atomic parameters like sub-shell fluorescence yields, Coster-Kronig transition probabilities and emission rates.