Inner-shell vacancy production and multiple ionization effects in 0.1-1.75 MeV/u Mn, Fe, Co, Ni, Cu + Au, Bi collisions

Vacancy production in 0.1-1.75 MeV/u Mn, Fe, Co, Ni, Cu + Au, Bi collisions has been studied by measuring integral inner-shell ionization cross sections and average outer-shell ionization probabilities at the Van de Graaff tandem accelerator of NIPNE, Bucharest. X-ray spectra induced by ion beams of Mn, Fe, Co, Ni and Cu impinging on solid-foil targets of Au and Bi of 100 μg/cm2 thickness have been measured. The average multiple ionization probabilities of the outer-shells were obtained by measuring the yield and energy shifts of the X-rays and compared with calculations in the independent electron approximation. We report here total ionization cross sections for the K-shell of the projectile and Li subshells (i=1,2,3) of the target as well as vacancy sharing probabilities corrected for the effect of multiple ionization. Some specific effects for these heavy collision systems in the K-L level matching region or due to the high charge state of the ion inside the solid target can be observed. These result in high inner-shell ionization cross sections and strong perturbation of the atomic shells of both collision partners. The experimental results are discussed in terms of simple model calculations. (authors)