Orientation and alignment effects for electron transfer in keV ion-atom collisions

Abstract

Recent theoretical results for one-electron transfer between excited target atoms and keV ions are reviewed. Semi-classical close coupling calculations with an atomic and a molecular orbital expansion are compared for the Li +Na(3p) system in the energy range 0.17–2.25 keV/amu. The question to what extent the effects of initial and final state orbital orientation or alignment seen in angular differential cross sections can be studied with integral state-to-state cross sections is addressed. The validity of simple models such as velocity matching, a propensity rule for orientation and alignment due to orientation in the transfer region is discussed.