Dynamics of molecular Penning ionization: angle-energy distributions of N 2+ from He *(2 1S)+N 2

Abstract

Angle-energy distributions resulting from the Penning ionization of N 2 by metastable singlet helium He *(2 1S) at collision energies of 2.5 and 4.4 kcal/mol have been measured using crossed supersonic molecular beams and a rotatable mass-spectrometric detector. Predominantly forward scattering of N 2 + is observed, and although substantial backscattering is also present at both energies, the collision intermediates are mainly short-lived. Both the sharpness of the forward-scattering peak and the mean recoil energy increase at the higher energy. The results are compared to quantum scattering calculations based on a recently proposed set of potential surfaces.