Excitation of bands of the first negative system of the N2+ ion in collisions of N+ and O+ ions with N2 molecules

Absolute values of the excitation cross sections of the (0,0) bands [for O+(4S), O+(2P)-N2 pairs] and the (0,0), (0,1), (1,2), and (2,3) bands [for N+(3P)-N2 pairs] of the first negative system of the N2+ ion have been measured in collisions with nitrogen molecules of nitrogen and oxygen ions in the ground state and in a metastable state in the interval of ion energies 1–10 keV. The process of excitation of the (0,0) band of the first negative system of the N2+ ion by oxygen ions in the metastable 2P state is of a quasi-resonant character. The presence in the beam of ions in metastable states was monitored by measuring the excitation efficiency of the (0,0) band λ3914 Å of the N2+ ion in different operating regimes of the highfrequency ion source. For N+ ions in the 3P ground state, as the collision frequency is decreased the relative vibrational population of the v′=1 and v′=2 levels of the B2Σu+ state of the N2+ ion is observed to deviate strongly from the value calculated in the Franck-Condon model.