STATE-RESOLVED ENERGY AND ANGULAR DIFFERENTIAL MEASUREMENTS OF THE PRODUCT DISTRIBUTION IN THE REARRANGEMENT REACTION H- + D2-]HD(V') + D-

We report on a crossed beam study of the reaction H- + D2(upsilon = 0) --> HD(upsilon') + D- in the collision energy range E(rel) = 0.3-3 eV. From the vibrationally state-resolved energy and angular spectra of the D-product, ions, we derive state-specific differential cross sections in the CM system. Absolute units are obtained by using elastic H- + He scattering as a reference system. The angular distribution of the D- product ions is strongly forward peaked, which indicates that the reaction occurs preferentially for a collinear configuration of the reactants. By integrating over angles and summing over partial cross sections (for individual upsilon'), we determine the absolute total cross section of the reaction. The reaction has a threshold at E(rel) = 0.42 +/- 0.12 eV. The cross section rises to a maximum of 2 x 10(-16) cm2 near 1.5 eV and then rapidly decreases again.