Dissociation of CO induced by ions: II. Dissociation pathways and states

Abstract

The dissociation of CO q+ ions (q 3) produced in collisions of 2-10 keV amu −1 He 2+ ions with CO has been studied by time-of-flight methods. From the time-of-flight spectra the energy released in the dissociation process is determined. Our results for the kinetic energy release of CO 2+ and CO 3+ ions are compared with the results of other ionization methods. Clear differences are observed. We observe a counterintuitive dependence of the kinetic energy release on the velocity of the He 2+ ions, i.e. the kinetic energy release increases with decreasing velocity.

Dissociative double capture in18O8++ CO2collisions1

“…From another point of view our relative weights given above also demonstrate the importance of the target excitation in a double capture process (see also the comparison with the argon target data in [24] ). A similar conclusion was stressed by Folkerts et al in the He 2+ + CO collision, but from TOF spectra of charged fragments alone, without performing a coincidence with electrons [6]; therefore their result is an average over all the possible capture processes. On the other hand, the result discussed here concerns a well-specified double electron transfer.…”

“…On the other hand, molecular targets may give additional information on the energy transfer to the target accompanying a multiple capture process, provided an adequate analysis of the fragmentation patterns is made. An example can be found in the experiment of Folkerts et al [6], but it concerns an analysis of charged fragment time-of-flight spectra alone.…”

Velocity and charge-state dependence on the Coulomb explosion of N2, under the impact of highly-charged ions at intermediate velocities

“…The resulting transient molecular ion eventually decays into the constituent atomic and (or) molecular ions via Coulomb explosion. The degree of ionization and the KER distributions, in general, are expected to depend on the charge state (q p ) and velocity (v p ) of the projectile ions [16,17,19,37,38].…”

“…While in the case of region C, the electron emission from the relatively tightly bound inner-valance orbital comes into the picture, which requires more energy deposition. This may also be understood qualitatively within the domain of the over-the-barrier model [37,46]. It is seen that the electron capture phenomena happen within the population distribution of electronic states defined by a reaction window [46].…”

“…with decreasing projectile charge states. This increment in the capture distance directly leads to the lowering of energy deposition with increasing q p , as the direct energy transfer from projectile to target becomes less probable with larger distance [37].…”