Constant initial state (CIS) spectroscopy in the study of the decay of core-to-bound resonances in N2

Constant initial state (CIS) photoemission spectra of the N2 1piu-1 and 3sigmag-1 states have been measured in the photon energy range corresponding to the N 1stopi* core-to-bound transition, where they acquire intensity from participator decay. The resolution was sufficiently high that the spectra could be recorded individually for the first four vibrational components of the 1piu-1 state and for the first two vibrational components of the 3sigmag-1 state. Differences in the spectra for these two final states are discussed in terms of their potential curves compared to that of the intermediate neutral excited state. We point out the potential usefulness of the CIS method for elucidating the details of the molecular potential.