Collision Spectroscopy. IV. Semiclassical Theory of Inelastic Scattering with Applications to He+ +Ne
A two-state semiclassical theory of elastic and inelastic scattering is formulated and compared to the Stueckelberg-Landau-Zener, distorted-wave, and close-coupled two-state methods. The semiclassical theory is shown to explain the physical origin of oscillatory structure on both the elastic and inelastic differential cross sections, and of a rainbowlike structure in the elastic scattering. Using simple and plausible interactions, theoretical elastic and inelastic differential cross sections are calculated and compared to the experimental measurements of the elastic and inelastic differential cross sections for He+ +Ne. The scattering is characterized by a 2Σ-2Σ crossing located at rx=2.02 a. u. with an energy Ex=0.530 a. u., leading to the final state He++Ne* (2p5 3s). The interaction energy at the crossing is found to be V12(rx)=0.0082 a. u.