Electron capture in He2+-metastable H (2s) low energy collisions

The total and partial charge exchange cross sections for the collision He 2+ -H (2s) at impact velocities between 0.05 and 0.6 au are calculated. The transition amplitudes are obtained from the perturbed stationary states approximation corrected to account for the electron momentum transfer problem. It is shown that in the present case the results are very sensitive to the choice of the common translation factor (CTF) used to perform the calculations. Therefore, the authors use the Euclidean norm method in order to optimize the CTF. Finally, we study the effect of the Stark interaction before the collision on the process of capture.