Luminescence measurements of hyperthermal Xe2+ + O2 and O+ + Xe collision systems†
Emission excitation cross sections are recorded for collisions between Xe2+ + O2 and O+ + Xe over a collision energy range of approximately 2 to 900 eV in the center-of-mass (Ecm) frame. Emissive products of the O+ + Xe reaction are examined in the 700–1000 nm optical range and include neutral atomic oxygen emissions and neutral xenon emissions. Atomic emission products of the O+ + Xe collision appear to have measureable cross sections near Ecm = 14 eV and increase in intensity until about Ecm = 60 eV where they remain approximately constant for the remainder of the measured collision energies. For the Xe2+ + O2 collision system, O2+ charge transfer products are measured through fluorescence of the O2+(A–X) and (b–a) manifolds over the 200–850 nm window. Total cross sections for both manifolds do not vary beyond the experimental precision at all measured energies. Vibrational populations are derived from a fitting of the experimental data. The populations are found to deviate from a Franck–Condon distribution at all collision energies and appear to be well-modeled within a multi-channel Landau–Zener framework over the collision energy range measured.