Analysis of the Thirteenth Spectrum of Neodymium, Nd XIII

Abstract

Spectra of Cd-like Nd XIII ion excited in laser-produced plasma and lowinductance vacuum spark sources have been investigated in the far vacuum ultraviolet region. The analysis has been based on energy parameter extrapolation in the Cd I isoelectronic sequence by using a Cowan computer code. 136 spectral lines have been classified in the 113 Å-605 Å region in Nd XIII spectrum, out of which 134 were newly classified lines. All energies of the levels of the 5s5p, 5p 2 , 5s5d, 5s6s, 4f 2 , 4f5s, 4f5p, 4f5d, 5p5d, 5s5f and 5s6p configurations have been determined. Least-Squares-Fitted calculations were carried out to interpret the experimentally measured energy structure of Nd XIII ion.

Atomic properties of Cd-like and Sn-like ions for the development of frequency standards and search for the variation of the fine-structure constant

“…Our values are in excellent agreement with experimental energies from [20][21][22] for Cd-like Ba 8+ , La 9+ , Ce 10+ , with similar level of agreement for all three ions. However, we find a significant discrepancy with experimental values from [23,24] for Pr 11+ and Nd +12 which might indicate a problem with the experimental level identification. Detailed study of higher-order, Breit, QED, and higher partial wave contributions was carried out to evaluate uncertainties of the final results for each ion.…”

“…The 5s5p energies agree with experiment to about 0.6%. However, the differences with the experiment for Nd 12+ [24] energies are anomalously large, 1.6-3% for all states listed in Table I except 5s5p 1 P 1 which is in excellent agreement with experiment. These differences are much larger than our estimated upper bound on the uncertainty of our results listed in column "Unc".…”

“…To explore the discrepancy of our energies with experiment for Nd 12+ , we calculated the energies of the other three ions of Cd-like isoelectronic sequence, La 9+ , Ce 10+ , and Pr 11+ , and compared the results with the experimental values from [21][22][23]. We present the comparison of theoretical energies with experiment for all 5 consecutive ions of Cd-like isoelectronic sequence, Ba 8+ [20], La 9+ [21], Ce 10+ [22], Pr 11+ [23], and Nd 12+ [24] in Table II. All energies are given relative to the 5s 2 1 S 0 ground state in cm −1 .…”

Ground-state configurations and unresolved transition arrays in extreme ultraviolet spectra of lanthanide ions

“…As noted in [1], systematic analysis of spectra in higher ion stages of lanthanum and cerium have been performed: La VII [9], La XI [10,11], La XIII [12], Ce III [13], Ce V [14], Ce VI [15], Ce IX [16], Ce X [17] and Ce XIV [10][11][12]. More recently progress has been made in analysing Cd-like ion spectra from Xe VII -Eu XVI [5, 18,19] and Pd-like ion spectra [20].…”

Extended analysis of Xe VII and Xe VIII

“…In the studies related with the stimulated emission of xenon, the understanding of the population mechanisms that affect the Xe VII laser action requires knowledge of the spectral analysis corresponding to this ion. Results for ions in the Cdlike isoelectronic sequence were published [7][8][9][10][11][12][13][14][15][16][17] and previous works about cadmiumlike xenon were carried out by different groups of researchers [18][19][20][21][22][23], who used various experimental methods such as beam-foil spectroscopy, spark-light sources, laserproduced plasma, theta-pinches, etc. Larsson et al [24] obtained energy levels of the 5s6s, 5s5d and 5p 2 , and 5s4f configurations by collision-based spectroscopy.…”