An experimental and theoretical study of the doubly charged ion O2+2

Abstract

The energy levels of triplet states of doubly charge oxygen, obtained using double charge transfer spectroscopy, have been examined in the light of ab initio calculations. Four peaks were found in the double charge transfer spectrum with energies of 41.1±0.2, 43.2±0.2, 48.2±0.3, and 51.3±0.3 eV, respectively. The first and third peaks have been assigned to the 3Σ+u and the 3Πu excited states, respectively. The second peak has been assigned to the population of the 3Πg states. The configuration of the state at 51.3 eV is unknown. The effect of the symmetry rule Σ+↔/Σ− is discussed and the validity of the spin conservation rule is demonstrated when a proton is used as a projectile in this experimental technique.