COLLISIONAL EXCITATION OF O-2(-2(+) ELECTRONIC STATES VIA SINGLE-ELECTRON CAPTURE BY B2+ IONS() AND N)

High-resolution translational energy spectra have been obtained for si ngle-electron capture by 4-keV B2+ ions in collision with Ne, O-2, and N-2. The Ne spectrum is used for accurate determination of the zero e nergy-change position for subsequent analysis of the complex molecular spectra. Six capture channels have been unambiguously identified for the O-2 spectrum; two of these involve capture-excitation, which leave s the O-2(+) ion in its fourth excited state, responsible for subseque nt emission of the first negative band system [b(4) Sigma(g)(-) --> a( 4) Pi(u)] of O-2(+). The N-2 spectrum consists of seven narrow spectra l features, four of which are identified with capture channels from wh ich the first and second excited electronic states of the N-2(+) ion a re accessed. These constitute the upper states of the Meinel [A(2) Pi( u) --> X(2) Sigma(g)(-)] and first negative [B-2 Sigma(u)(+) --> X(2) Sigma(g)(+)] band systems of the N-2(+) ion. (C) 1995 Academic Press, Inc.