Imaging state-to-state reactive scattering in the Ar+ + H2 charge transfer reaction

摘要

The charge transfer reaction of Ar+ with H2 and D2 has been investigated inan experiment combining crossed beams with three-dimensional velocity mapimaging. Angle-differential cross sections for two collision energies have beenobtained for both neutral species. We find that the product ions are highlyinternally excited. In the reaction with H2 the spin-orbit excited Ar+ state'scoupling to the 'resonant' vibrationally excited product H2+(v=2) dominates forboth investigated energies, in line with previous investigations. The observedangular distributions, however, show significantly less back-scattering thanwas found previously. Furthermore, we discovered that the product ions arehighly rotationally excited. In the case of Ar+ reacting with D2 theenergetically closest lying vibrational levels are not strictly preferred andhigher-lying vibrational levels are also populated. For both species thebackward-scattered products show higher internal excitation.