Fluorescence emission at core-to-Rydberg excitations in the N2 molecule

Abstract

Fluorescence emission at the N 1s edge of the N2 molecule has been studied with synchrotron radiation excitation. The partial fluorescence yields in the ultraviolet (250–320 nm) and visible (300–650 nm) wavelengths were collected by scanning the photon energy across the core-to-Rydberg excitations and the N 1s ionization potential (IP). When compared to the total ion yield, both fluorescence yields are most enhanced at the excitations to high Rydberg orbitals. A discrete structure appears just below the N 1s IP only in the UV yield and is assigned to core-valence doubly excited states. Dispersed fluorescence spectra in selected wavelength windows were measured at several photon energies in order to find out which fragments are responsible for the enhancement of fluorescence emission just below the N 1s IP. The excitation functions determined and considerations on de-excitation pathways indicate that the main responsible is the N+ ion.