Fragmentation processes of the core-excited NO molecule

Abstract

Ionization and fragmentation processes of the NO molecule following the excitation of the nitrogen 1s electron have been studied by means of high-resolution mass-selective ion-yield measurements. The yields of and ions acquired with a quadrupole mass spectrometer (QMS) and a linear time-of-flight spectrometer (TOF) show surprising differences at the threshold region suggesting the selective attachment of the excited core electron to the centre during the dissociation of the ion. The fragmentation branching ratios corrected for the angular and kinetic energy effects are presented. The kinetic energy distributions of the and fragments have been extracted for a number of Rydberg states manifesting a significant dependence on l quantum number and energy of the primary excited Rydberg level. The lifetime of the core-excited state has been found from the shape of the low kinetic energy electron spectra acquired above the and thresholds.