title: Probing the valence character of O 1s-->Rydberg excited O2 by participator Auger decay measurements and partial ion yield spectroscopy following x-ray absorption.
abstract: The valence character of O 1s-->Rydberg excited O2 is investigated by means of participator Auger decay spectroscopy, performed at selected photon energies across the K-shell resonance region, and by means of partial ion yield x-ray absorption spectroscopy. For several of the excitation energies studied, the authors find substantial sigma*(4Sigmau-, 2Sigmau-) valence character being mixed with nssigma and npsigma (4Sigmau-, 2Sigmau-) Rydberg states. An experimental indication of a coupling between the channels associated with quartet and doublet ion cores is considered and discussed. New spectroscopic constants are derived for the singly ionized X 2Pig state of O2 based on the observation of at least 20 vibrational sublevels.
authors.affiliation: Department of Physics, Uppsala University, Box 530, SE-751 21 Uppsala, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Feifel
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: De Fanis
authors.forename: R
authors.initials: R
authors.lastname: Sankari
authors.forename: L
authors.initials: L
authors.lastname: Karlsson
authors.forename: S
authors.initials: S
authors.lastname: Sorensen
authors.forename: M-N
authors.initials: MN
authors.lastname: Piancastelli
authors.forename: G
authors.initials: G
authors.lastname: Prümper
authors.forename: U
authors.initials: U
authors.lastname: Hergenhahn
authors.forename: K
authors.initials: K
authors.lastname: Ueda