Resonant Ion Pair Formation in Electron Collisions with Ground State Molecular Ions

Resonant ion pair formation from collisions of electrons with ground state diatomic molecular ions has been observed and absolute cross sections measured. The cross section for HD+ is characterized by an abrupt threshold at 1.9 eV and 14 resolved peaks in the range of energies 0 less than or equal to E less than or equal to 14 eV. The dominant mechanism responsible fbr the structures appears to be resonant capture and stabilization, modified by two-channel quantum interference. Data on HF+ show structure correlated with photoionization of HF and with dissociative recombination of electrons with this ion.