Orientation propensity for states populated by electron capture in B3+/He collisions

The orientation of the (1s22p)2P excited state of the doubly charged B2+ ions, resulting from electron capture in collisions of triply charged B3+ ions with He, is investigated theoretically. The collision dynamics are described using a quasi-molecular adiabatic representation of the system and calculations are carried out in the range of ion energies from 0.3 to 1.5 keV. Our results, which are in excellent agreement with experiment, confirm the strong propensity for orientation of the 2P state at small scattering angles. The main contributing factors responsible for the orientation are carefully analysed. (Author)