Investigation of the transfer ionization process in collisions of partially stripped ions on He

In this paper a projectile ion-recoil ion coincidence technique is used to investigate the transfer ionization processes in collisions of 0.22-6.30 MeV C^q+ ions and 0.25-6.35 MeV O^q+ ions (q 1, 2, 3, 4) with the He atom separately. The cross section ratio f of transfer ionization to single electron transfer is measured, and the dependence of f on both charge state q and energy E of the projectiles is investigated. The electron-structure and the mechanisms leading to transfer ionization affect the dependence of f on q and E. Our measurements, along with other data published previously, suggest a similar dependence of f on charge state and energy of projectile for partially stripped ions over a large energy range. The maximum value of f is approximately 0.17q^0.60; the energy corresponding to maximum f is about 160q ^0.60 keV/u.