Electron capture in collisions of excited Na*(3p) atoms with He+ ions at 0.1--7 keV/u: Effects of alignment of the initial Na*(3p) orbital

Electron-capture and deexcitation processes in collisions of excited Na*(3p) atoms with He+ ions are studied in the energy range 0.1--7 keV/u by using the molecular-orbital-expansion method within the semiclassical framework. The integral alignment (A20), alignment angle (γ), and orientation (O) parameters of excited He(2 1P,2 3P) orbitals resulting from electron capture are also determined. Furthermore, the effects of the initial alignment of the Na*(3pm) orbital on the cross sections, O, and γ parameters are investigated. The present results show that the ratio of theoretical cross sections for electron capture by the He+ ion in collisions with the Na*(3p) atom and the ground state Na(3s) atom, respectively, is nearly equal to unity in the energy range studied here. The results also show that the O and γ parameters are significantly different for the singlet and triplet manifolds, implying that different collision dynamics for He(2p) formation govern in each manifold. These parameters can be effectively controlled by adjusting the initial alignment of the Na*(3p) orbitals