Superoxide anion (O2-) collisions with CO2 molecules in the energy range of 50-950 eV

A novel gas-phase molecular scattering study is reported for O2- collisions with CO2 for impact energies ranging from 50 to 950 eV in the lab frame. The absolute total electron detachment, relative total, and partial ionization cross sections have been measured within this energy range together with the positive ion yields. The primary anionic beam projectile is produced in a pulsed hollow cathode discharge induced plasma, and its interactions with the neutral molecular target occur in a gas cell at a well-known constant pressure. For impact energies above 500 eV, high mass (m > 44 u) charged complexes have been detected. With the aid of a theoretical study using ab initio methods, we propose a mechanism to infer the formation of these cationic species, which have been assigned to projectile-target stable compounds (CO3+ and CO4+).