A STUDY OF NE2+ AND AR2+ SATELLITE STATES OBSERVED BY THRESHOLD PHOTOELECTRONS COINCIDENCE SPECTROSCOPY

The Ar2+ and Ne2+ spectra have been studied from their respective thre sholds up to their respective triple ionization potentials by threshol d photoelectrons coincidence (TPEsCO) spectroscopy. The np(4), nsnp(5) and ns(0)np(6) (n = 2, 3 in Ne and Ar, respectively) states of the di cations as well as the np(3)n'l satellite states, where two electrons are ejected and one is promoted into an unfilled orbital, have been ob served. This study is the first extensive observation of the satellite states of dications by electron emission spectroscopy and extends the previous observations by optical emission spectroscopy to the region of the triple ionization threshold. New features have been discerned i n the spectra and an assignment is proposed based on previous results from optical spectroscopy and on calculations with an atomic multiconf igurational Dirac-Fock code.