+ 2 (A 2Πμ→X 2Π= (g−italic)=) and O+2 (b 4Σ−g→a 4Πu) emissions by photoionization of O2

Cross sections for the production of the O2+ (A 2Πu→X 2Πg) fluorescence in the 2000–5000 Å region and the O2+ (b 4Σ−g→a 4Πu) fluorescence in the 3000–8000 Å region have been measured at selected atomic emission lines and throughout the synchrotron radiation continuum from 175 to 740 Å. The electronic transition moments and vibrational populations of the resulting ions have also been determined. The partial cross section for producing the O2+ (b→a) system shows structure closely related to the total absorption spectrum in the 500–700 Å region. In contrast with this, the O2+ (A→X) system shows only weak structure and its spectrum is quite different from that of the absorption spectrum. The various channels and processes for evolution of the O2 molecules excited into these Rydberg states are discussed.