Multiple ionization effects in Fe, Co, Ni, and Cu + Bi collisions

Available as short communication only. The multiple ionization effect in the determination of 3dσ vacancy production cross sections and sharing probabilities in asymmetric quasimolecular collisions near K-L level matching for the collision systems Fe, Co, Ni, and Cu+Bi in the energy range 0.25-1.75 MeV/u have been studied. The experimental energy and intensity shifts of some projectile and target X-ray lines, as well as Dirac-Hartree-Fock calculations, have been used to estimate average single particle probabilities for multiple ionization of projectile L- and target M- shells. Using these estimates and the standard procedure, the experimental 3dσ production cross sections and sharing probabilities have been corrected for multiple ionization. The influence of the multiple ionization induced by increasing the binding energy of the molecular orbitals implied in vacancy sharing will be discussed. (Author) 2 Refs