ALIGNMENT AND ORIENTATION FOR CHARGE-EXCHANGE IN LI-NA(3S, 3P) COLLISIONS .1. DIFFERENTIAL AND TOTAL CROSS-SECTIONS()

The alignment and orientation effects for charge exchange in 1-1.5 keV Li+-Na(3s, 3p) collisions are studied by semiclassical close-coupling calculations employing adiabatic molecular data and a common electron translation factor. The differential cross sections from Na(3s) to Li (2s) and Li(2p) are compared to experiment, a large orientation effect is predicted for charge exchange to Li(2p(+/-1)). From Na(3p) the cha rge exchange is important only to the Li(2p) channel, the correspondin g alignment and orientation effects are calculated. The orientation ef fect follows the propensity rules. The formulae for total and differen tial cross sections for a transition from aligned p to p state or from oriented p to p state are derived. Two differential total cross secti ons for oriented p(+/-1) to p(+/-1) states can be defined, the same fo r aligned p+/-45 degrees to p+/-45 degrees states. The important role of the translation factor is discussed and a four state model is able to describe charge exchange from Na(3p) to Li(2p) at large impact para meters.