Non Franck-Condon effects in photoionization of molecular oxygen
We present a theoretical and experimental analysis of non Franck-Condon effects in photoionization to the b 4Σg- state of O2+. Experimentally, by dispersing the synchrotron radiation induced O2+ b 4Σg- - a 4Πu fluorescence we derive the b 4Σg- state vibrational branching ratios in the excitation energy range 21–34 eV. The vibrational branching ratios reveal features in the region 21–28 eV, indicat