State-selective differential and total cross sections for single-electron capture in He+-He collisions

Theoretical investigations on state-selective total and angular differential cross sections for single-electron capture in collision of He+ with ground state helium atom has been presented within the framework of four-body distorted-wave model in the energy range of 30-4000 keV. In this model, distortions in the initial channel related to the Coulomb continuum states of the target and the active electron in the field of residual projectile ion are included. Here, the electron in the projectile plays the role of screening of the projectile ion. In this formalism, the dielectronic interaction 1/r(12) explicitly appears in the perturbation potential V-i of the prior form of transition amplitude. Moreover, we include the interaction of the projectile with the passive electron in the target in both prior and post forms of the transition amplitude. The main purpose of the present study is to investigate the relative importance of this interaction to the state-selective total as well as projectile angular-differential cross sections with impact energies. The angular-differential cross sections (DCS) for ground-state transfer exhibit an oscillatory structure at intermediate energies. This oscillatory structure demonstrates the analogy of atomic de Broglie's matter-wave scattering with Fraunhofer-type diffraction of light waves. The present theoretical results are compared with the available experimental data as well as few theoretical calculations. We find that our computed results, particularly in the prior form, indicate better agreement with the experimental data than that of the post form. Post-prior discrepancy of the total cross sections does not exceed 25% throughout the energy range considered.