Decay pathways of superexcited states of nitrous oxide

The ionization and ionic dissociation of the superexcited state of N₂O are studied by using electron energy loss spectroscopy and positive ion time-of-flight mass spectroscopy at different momentum transfers; that is, 0 and 0.23 a.u. (atomic unit). The transitions at 13.8 eV and 14.0 eV are reassigned as 3pπ (000) and 3pσ (000) converging to A²Σ⁺, respectively. The competition between the main decay pathways of superexcited states at different momentum transfers is revealed. It is found that 3dσ converging to C²Σ⁺ mainly decays into N₂O⁺ while 4dσ can decay into both N₂O⁺ and NO⁺.