High-spin inner-shell excited states in few-electronneon: quintets and sextets

Abstract

Quintet states in Be-like Ne VII and sextet states in B-like Ne VIhave been investigated by beam-foil spectroscopy in the XUVspectral region. The wavelengths of the n = 2-n' = 3 transitionsfrom the inner-shell excited terms 1s2l2pn'l' 5L;l = s,p; l' = s,p,d and 1s2l2p2n'l' 6L; l = s,p; l' = s,p,d are obtainedusing Hartree-Fock calculations and linear Z-expansions in therespective isoelectronic sequences. Lifetime measurements arepresented for some n = 3 quintet levels. Spectral lines areassigned to n = 2-n' = 4 transitions supported by 32 newline identifications in Ne VI, VII and IX. A class of metastablelow-spin inner-shell excited states in Be-like ions, possiblecandidates for XUV-laser schemes, are also discussed. Finally,metastable 3l3l' sextet states in the B sequence areintroduced, one of which might be bound in Be-.