Total, state-selective and differential cross sections for single electron capture in He+-He collisions

The total, state-selective and angular-differential cross sections for single electron capture in He+-He collisions are investigated by using the two-center atomic orbital close-coupling method in the energy range 0.2-650 keV/u. The angular-differential cross sections for electron capture to the ground state of He are calculated at collision energies of 0.625, 1.25, 7.5, 25, 60, and 150 keV/u within the eikonal approximation for the scattering amplitude. Both total and differential cross sections are compared with the available experimental and theoretical data. The calculated differential cross sections exhibit oscillatory structures with exponentially decreasing amplitude and frequency decreasing with increasing the collision energy. They show good agreement with the experimental data for scattering angles theta < theta(0), where theta(0) decreases with increasing the collision energy (theta(0) approximate to 0.2 deg for E = 0.625 keV/u, theta(0) approximate to 0.006 deg for E = 150 keV/u). We found out that for a given collision energy, the oscillatory structure of angular-differential cross section is strongly correlated with the oscillatory structure of the impact parameter dependence of electron capture probability.