FRAGMENTATION PROCESSES OF THE CORE-EXCITED NO MOLECULE

Ionization and fragmentation processes of the NO molecule following th e excitation of the nitrogen 1s electron have been studied by means of high-resolution mass-selective ion-yield measurements. The yields of N+, O+ and NO+ ions acquired with a quadrupole mass spectrometer (QMS) and a linear time-of-flight spectrometer (TOF) show surprising differ ences at the N(1s(-1)) threshold region suggesting the selective attac hment of the excited core electron to the N+ centre during the dissoci ation of the NO+ ion. The fragmentation branching ratios corrected for the angular and kinetic energy effects are presented. The kinetic ene rgy distributions of the N+ and O+ fragments have been extracted for a number of Rydberg states manifesting a significant dependence on l qu antum number and energy of the primary excited Rydberg level. The life time of the core-excited N(1s(-1)) state has been found from the shape of the low kinetic energy electron spectra acquired above the (1) Pi and (3) Pi thresholds.