Ion Momentum Imaging Study of the Ion-Molecule Charge Exchange Reaction of Ar+ + CO2

摘要

Three-dimensional ion momentum imaging is developed in a combination of ion velocity map imaging technique and delay-line anode ion detection, and it is applied for the ion-molecule charge exchange reaction between Ar+ and CO2. In a center-of-mass collision energy range of 7.23-15.96 eV, CO2+ products are primarily populated at the ground state X-2 Pi(g) and the single-electron excited states A(2)Pi(u), B-2 Sigma(+)(u), and C-2 Sigma(+)(g); the multielectron excited states of CO2+ are also found at the higher collision energies. The production efficiency profiles of CO2+ are distinctly different from the photoionization electron spectrum of CO2, implying that the charge transfer from Ar+ would be not fast as expected. The strong electron correlations in the short-lived intermediate (Ar-CO2)(+) should be responsible for the CO2+ yields at the multielectron excited states.