Charge transfer in low-energy collisions of He2+ with atomic hydrogen

Using the Oak Ridge National Laboratory ion-atom merged-beams apparatus, absolute total charge-transfer cross sections have been measured for collisions of He2++H over a range of energies from 380 to 2620 eV/u. The experimental results are compared to previous measurements using different experimental techniques. A hidden-crossing coupled-channel (HCCC) calculation is performed in the collision energy range of 10 to 3000 eV/u and is compared with the measured data as well as with other theories. The HCCC calculation, which is deemed accurate below 1000 eV/u, is also used to determine differential cross sections. The resultant angular scattering information is used to correct the merged-beams data, which is characterized by a large but limited angular acceptance at these collision energies. Our combined experimental and theoretical study provides an improved benchmark for this fundamental system.