Doubly excited states in lithiumlike Si XII, S XIV and Ar XVI

Collision Spectroscopy of Quartet and Doublet Transitions in doubly excited Ne7+

“…[11] and Khardi et al [12] and theoretical and empirical data given by Safronova et al [25]. This interpolation and further interpolations and extrapolations in the section was obtained by a Ðt along isoelectronic sequence of p/(f ] a)2 vs. f with p denoting the wavenumber of the transition and f the core charge of the element.…”

“…The Ðne structures were resolved and the lifetimes of individuals levels were measured in C IVÈO VI by 2p2 4P J Livingston and Berry, in Ne VIII by Knystautas and Druetta [8] and in Al XI, Si XII by the Lyon group on spectra obtained by beam-foil process with energetic beams [9]. Further investigations of the spectra in the VUV region were performed by the groups of Lie`ge [10], Bochum [11] and Lyon [12]. They measured transitions down to n \ 2 and n \ 3Èn@ \ 4,5 transitions in C IV, N V, O VI, F VII and Mg X, Si XII, SX IV, Ar XVI.…”

Spectroscopic study of doubly excited levels in NeVII** and NeVIII**

“…Isoelectronic interpolations are based on previous studies on 3-4 transitions on core-excited quartet states in the lithium isoelectronic sequence [10]. Figure 1 shows a portion of the neon spectrum taken at 10.4 MeV which contains several of the lines arising from doubly excited states in Ne VIII * * .…”

“…In order to respect the assignment of the 28.374 nm line based on theoretical calculations, as well as on the systematics of the reduced transition wavenumber ν/ζ 2 versus ζ along the isoelectronic sequence, we ascribe this line to the 1s2p( 1 P)3d 2 D o -1s2p( 1 P)4f 2 F transition, labelled '*'. We then change the identifications of the corresponding lines observed by Blanke et al [12] in N V, O VI, F VII and Mg X, taking into account work by the Liège group [13] on B III, C IV and N V as well as lines identified by the Lyon group in Si XII, S XIV and Ar XVI [10]. The 28.516 nm line is then attributed to the 1s2s3d 2 D-1s2s4f 2 F o 'D' transition.…”