Single- and double-photoionization cross-sections of nitrogen dioxide (NO2) and ionic fragmentation of NO2+ and NO22+

Abstract

Abstract Single- and double-photoionization processes of nitrogen dioxide (NO 2 ) have been studied in the photon energy region of 37–125 eV by use of time-of-flight mass spectrometry and the photoion–photoion coincidence method together with synchrotron radiation. The single- and double-photoionization cross-sections of NO 2 are determined. Ion branching ratios and the partial cross-sections for the individual ions, respectively, produced from the parent NO 2 + and NO 2 2+ ions are also determined separately at excitation energies where the molecular and dissociative single- and double-photoionization processes occur simultaneously. It was found that dissociation of the parent ions is dominant both in single and double photoionization. The thresholds for the O + + NO + and N + + O + dissociation channels of NO 2 2+ are at 35.0 ± 0.3 and 43.6 ± 0.3 eV, respectively. Kinetic energy releases in these two dissociation channels of NO 2 2+ have also been elucidated.