MEASUREMENT OF M-X-RAY-PRODUCTION CROSS-SECTIONS IN GOLD BY PROTON, OXYGEN AND NICKEL ION IMPACT

Measurements of M-shell X-ray production cross sections in Au with pro ton, O5+ and Ni5+-ion impact have been performed. The energy of the in cident protons range from 1 to 5 MeV, oxygen ions from 66 to 72 MeV an d nickel ions from 58 to 87 MeV. The experimental results have been co mpared with Be predictions of the plane wave Born approximation (PWBA) and the perturbed stationary state theory with energy loss, Coulomb d eflection 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 the ories, however, strongly underestimate the X-ray cross sections measur ed with Ni-ion impact. The discrepancy between the experimentally meas ured 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 t ransition probabilities and emission rates.