Resonant electron transfer to multiply-ionized states of low-Z atoms produced in energetic heavy-ion - solid collisions

L-shell vacancies created in a chemically-bound target atom during a K-shell ionizing collision may be filled by resonant electron transfer (RET) processes prior to K X-ray emission. The resonance condition involves the matching of energy levels between the L-shell of the multiply-ionized target atom and the outer valence shells of neighboring atoms. The first evidence of RET was observed in the He ion-excited fluorine Kα satellite spectra of KF and SrF2 which show highly suppressed KL1 peak intensities when compared with spectra from the other fluorides. In this talk, it will be demonstrated that RET also occurs for the double K-vacancy hypersatellite states of oxygen created by bombardment of various solid oxides with 2 MeV/amu Ar5+ ions. Moreover, evidence for resonant multielectron transfer (RMET), in which two or more electrons are exchanged, will be presented in the case of the different oxides of titanium. Calculations, employing a point charge model with corrections for extra-atomic relaxation included, provide support for the RMET hypothesis