Investigation of transfer ionization in collisions of partially stripped carbon ions with helium at low to intermediate velocities

The ratios of transfer ionization (TI) to single-electroncapture (SC) cross sections have been measured for thecollisions of partially stripped C^q+ ions (q=1--4) withHe. The collision velocity ranges from 0.7 to 4.4v₀(v₀ is the Bohr velocity). The projectile-ion andrecoil-ion coincidence technique is used to separate theprocesses of TI and SC. The ratios reach the maximum when thevelocity is about 3.7v₀ This can be explainedqualitatively based on the two-step mechanism. The experimentalresults are also compared with the results calculated using theclassical trajectory Monte Carlo (CTMC) method. The CTMC resultsare in agreement with the experimental data basically. Thediscrepancies in higher velocity region are interpreted by theeffective charge effect.