Total cross sections for symmetric charge transfer reactions of O+2 in selected translational and internal energy states

Abstract

Total cross sections for the symmetric charge transfer reactions of O+2(X 2Πg) in selected translational and vibrational energy states have been measured in a single chamber experiment using a combination of photoion–photoelectron coincidence and ion time-of-flight analysis. The ion vibrational states and laboratory translational energies investigated were v=0–7 and 1–40 eV, respectively. The experimental results are compared to recently calculated symmetric charge transfer cross sections using the multistate impact parameter theory. We find that the theory overestimates the cross section by approximately a factor of 2. In addition, the theory predicts a slow drop in the cross section as a function of vibrational energy for v≳3, whereas the experiments indicate that the cross sections remain high and even increase with v for v≳5.