Multiply charged carbon ions and their production mechanisms in MeV/amu Arq+(q= 14-4) + CH₄collisions

Collisions between 1.05 MeV/amu Arq+ (q = 14, 10, 8 and 4) ions and CH4 molecules have been investigated using final charge-selected projectile-recoil ion time-of-flight technique. It is found that, in the overall ionization of target CH4 molecules, pure ionization processes without any change of the projectile charge is by far dominant over any other processes involving electron capture or loss of projectiles. Electron loss or capture processes of projectiles, though weak relative to pure ionization, are found to result in enhancement of the production of multiply charged atomic carbon ions. Another feature, probably not observed earlier, is the fact that in some electron loss and capture processes multiply charged carbon ions become more dominant than any other molecular ions, suggesting that such violent collisions result in nearly complete dissociation of the molecular ions.