Lifetimes and transition frequencies of several singlet ungerade states in N2 between 106 000 and 109 000 cm−1

Using a narrow-band tunable XUV source, ultra-high resolution 1 XUV + 1 UV two-photon ionisation spectra were recorded of transitions to several singlet ungerade states in 14N2 and 15N2 in the range 106 000-109 000 cm−1. The natural linewidths of the individual rotational spectral lines were determined and the resulting lifetimes were found to depend on vibrational level and for the c31Πu (v = 1) level also on isotope. Furthermore, accurate transition frequencies were determined and for several bands, lines near bandhead regions were resolved for the first time.