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

Quintet states in Be-like Ne VII and sextet states in B-like Ne VI have bee n investigated by beam-foil spectroscopy in the XUV spectral region. The wa velengths of the n = 2-n' = 3 transitions from the inner-shell excited term s 1s212pn'l' L-5; l = s, p; l' = s, p, d and 1s212p(2)n'l' L-6: l = s, p; l ' = s, p, d are obtained using Hartree-Fock calculations and linear Z-expan sions in the respective isoelectronic sequences. Lifetime measurements are presented for some n = 3 quintet levels. Spectral lines are assigned to n = 2-n' = 4 transitions supported by 32 new line identifications in Ne VI, VI I and IX. A class of metastable low-spin inner-shell excited states in Be-l ike ions, possible candidates for XUV-laser schemes, are also discussed. Fi nally, metastable 3l3l' sextet states in the B sequence are introduced, one of which might be bound in Be-.