Reactive scattering in D2+ + N and D2+ + O collisions

A merged beam apparatus was developed for the study of ion-neutral and neutral-neutral reactions which yield ionic products. The apparatus has been used to study the dynamics of D2+-(N,D)ND+ and D2+(O,D)OD+. Both reactions are exothermic for ground state reactants and products. In both cases the products are formed by direct mechanisms and are strongly peaked in the direction of the initial atom beam in c.m. coordinates. The product ions are formed with large amounts of internal energy. No evidence is found to indicate the formation of a long-lived collision complex in spite of the deep wells (>6 eV) in the potential energy surfaces for both systems and the low c.m. translational energies obtained in these experiments (less than or equal to 0.005 eV). The absolute reaction cross sections were measured for c.m. kinetic energies from approximately 0.002 to 26 eV for D2+(O,D)OD+. At energies below approximately 1 eV, the cross sections are proportional to orbiting cross sections calculated with the inclusion of attractive r-6 terms in the long range potentials in addition to the usual attractive r-4 terms of the Langevin treatment. The magnitudes of the observed cross sections above approximately 1 eV the cross sections fall off very rapidly indicating the opening of new product channels including dissociation