Experimental and theoretical studies of the He²⁺-He system: Differential cross sections for direct, single-, and double-charge-transfer scattering at keV energies

R. S. Gao, C. M. Dutta, N. F. Lane, K. A. Smith, R. F. Stebbings, and M. Kimura.

Phys. Rev. A 45, 6388 (1992)

Measurements and calculations of differential cross sections for direct scattering, single charge transfer, and double charge transfer in collisions of 1.5-, 2.0-, 6.0-, and 10.0-keV ³He²⁺ with a ⁴He target are reported. The measurements cover laboratory scattering angles below 1.5° with an angular resolution of about 0.03°. A quantum-mechanical molecular-state representation is employed in the calculations; in the case of single charge transfer a two-state close-coupling calculation is carried out taking into account electron-translation effects. The theoretical calculations agree well with the experimental results for direct scattering and double charge transfer. For single charge transfer, the agreement is less satisfactory because of the limited number of molecular states incorporated in our calculations. The present calculation identifies the origins of oscillatory structures observed in the differential cross sections.