Transfer ionization of the isocharge sequence ion and Ar collisions

The ratios of transfer ionization to single capture for isocharge C^q+, N^q+, O^q+, Ne^q+ ions on Ar atoms are measured by using position-sensitive and time-of-flight techniques. It is found that the ratio R_1 increases with nuclear charge Z in a q=4 sequence, and the ratio R_1 sequences have the minimum values at Z=7 and Z=8 in q=5 and q=6 sequences, respectively, and the ratio R_1 decreases with the increase in the nuclear charge Z in a q=7 sequence. The results may be explained within the frame of the statistical model. It may be concluded that the transfer ionization depends remarkably upon the electronic structure of the projectile. The projectiles used in this study have the same charge state and velocity, but different electronic structures. The dependence of the ratio R_1 on q is studied for Ne^q+-Ar collisions. The ratio R_1 is found to increase as q increases for Ne^q+－Ar collisions. The measured dependence of the ratio R_1 on q is compared with the calculation using the molecular Coulomb over-barrier model.