Kinematics of He+–CO2 dissociative charge exchange

The masses, energies and angular distributions of the product ions resulting from the dissociative charge exchange collision between He+ and CO2 have been measured at incident He+ energies of 8.7, 13.8, 60, and 200 eV. At the lower He+ energies the angular distributions are characteristic of complex formation with a significant amount of momentum transfer from He+ to the products. At the higher He+ energies there is little momentum transfer and the energy of the initially formed state of CO2+ is close to the recombination energy of He+. This state has been tentatively identified as the previously unobserved 2Φu. From the energy and angular distributions, a model for the dissociation of this state is developed. The model is consistent with previous optical measurements on the system and agrees with branching ratios predicted by the quasiequilibrium theory of mass spectra.