Q-Dependence of molecular ionization and fragmentation

The authors have studied 1 MeV/amu collisions with CO and CH4 targets and projectiles of charge q=1-13 in order to determine whether the cross sections for the formation of non-dissociated singly charged molecular ions follow a scaling law similar to the σ=Aqα law found for total ionization of atoms. Their results indicate that the cross sections for the formation of stabilized singly charged molecular ions for both molecules under investigation scale with projectile q according to the above equation. The behavior of the dissociation branching ratios of CO were also studied as a function of the projectile charge. Some measurements have been carried out for a fixed projectile charge q but with an increasing number of screening electrons in order to see the effect of these projectile electrons. The authors have also measured the production rate of CO2+ to see how its formation and stabilization depend on the strength of the interaction during the fast collision