Charge-state distribution of dissociated fragments from molecular C₂ ions passing through a capillary

Transmission properties of fast molecular C₂⁺ ions passing through a single tapered glass capillary were investigated. The velocity of C₂ projectiles ranged from 0.24-0.96 MeV per atom. Charge state distributions of dissociated fragments of C₁ were measured with an electrostatic analysis method. The average charge states of the dissociated fragments were found to increase with increasing the projectile velocity. Results are compared to an average charge state of single carbon projectile at the same velocity, showing that they are almost the same. This indicates that molecular dissociation occurs via collision in bulk of the capillary wall. We also found that almost all the C₂ ions transmitted without dissociation are transported keeping their initial charge state and their angular distributions are the same as a divergence of incident beam. (author)