Electron-induced vibrational deexcitation of H-2(+) - art. no. 032713

Using the Coulomb explosion imaging method, the change of the relative popu lation for the first six vibrational states of H-2(+) during the interactio n with low-kinetic-energy electrons has been measured. A model based on rat e coefficients for dissociative recombination and superelastic collision pr ocesses is developed to explain the time dependence of the relative vibrati onal populations. Using this model, we demonstrate that superelastic collis ions with rate coefficients of (1-4) x 10(-6) cm(3) s(-1) (about an order o f magnitude higher than available theoretical predictions) can explain the observed electron-induced vibrational deexcitation of H-2(+).