Observation of doubly excited Rydberg states of N2O by positive ion–negative ion coincidence spectroscopy

Ion-pair formation processes of N2O are studied in detail using synchrotron radiation in the 24–34 eV photon energy range. Positive ion–negative ion coincidence (PINICO) spectroscopy makes it possible to distinguish dissociation into three bodies, O−+N++N, from dissociation into two bodies, O−+N+2. The photodissociation efficiency curves for the two processes are measured. Several resonance-like peaks in the curves are assigned to doubly excited Rydberg states of N2O from an analysis of kinetic energy release in dissociation.