The spectrum of NeV

Abstract

A new investigation of the Ne V spectrum is reported. The beam-foil method has been used to produce spectra at two different energies (1.2 MeV and 2.5 MeV) between 450 and 1100 Å. Sixty-five lines of Ne V have been newly identified. Fifty levels have been determined for the first time and energies have been revised for seven levels.

Relativistic multireference many-body perturbation theory calculations on F-, Ne-, Na-, Mg-, Al-, Si- and P-like xenon ions

“…Because of its longevity (a level lifetime of about 10 ms has been measured in a storage ring experiment of Si-like Fe 12+ ions [73]), it probably is quenched in many laboratory plasmas. Spectrally resolved observations of the decay branches do not exist, but the decay of the (not as long-lived) 3 F o 3 level of the same term has been identified in delayed beam-foil spectra of ions of iron group elements [74], in agreement with calculations of the same type as used here [22]. The new assignment refers to a transition not assigned (to our knowledge) in any other Si-like ion; hence there is no expertise and isoelectronic comparison to help judge the validity of the assignment, beyond our calculation and the supporting argument that in beam-foil spectra the levels with the highest J-values often are amply populated.…”

“…If an experimental spectrum was to show a few hundred lines, and the theory predicted a few hundred lines, there would be no easy mapping of one set to the other, and most likely it would turn out (as it regularly does) that the experiment shows a plenitude of lines that are not identifiable from current calculations. As an example, we cite the long-drawn and not yet fully successful quest for the analysis of beam-foil spectra of four-to six-electron ions of an element as light as Ne (Z = 10) [2][3][4][5][6]. It would be a mark of substantial progress if even the most prominent lines in spectra of ions with two to four valence electrons could be predicted well enough to enable immediate identification within the experimental and calculational uncertainties.…”

“…3 P o 1 at 129.95 Å, the Al-like ion line at 130.32 Å and the Si-like ion line at 129.68 Å are blended. The theoretical MR-MP lifetime value of 160.5 ps for the Mg 3 P o 1 level is in good agreement with the MBPT lifetime of 163 ps.…”