Calculation of wavelengths and oscillator strengths in high-ZMg-like ions

Abstract

Wavelengths and oscillator strengths for transitions among the levels of the terms belonging to the 3s2, 3s3p, 3s3d, 3s4s, 3s4p, 3s4d, 3p2, 3p3d, 3p4s, 3p4p, 3p4d, 3d4s, 3d4p, 3d4d and 3d2 configurations of Mg-like Nd48+, Pm49+ and Sm50+ are systematically calculated using multiconfiguration-Dirac–Fock method. The predicted spectra of these three ions are, for the first time, extensively reported for n = 3–4 transitions in the 5–8 Å range and the variant trends of wavelengths and oscillator strengths along the isoelectronic sequence are discussed.

Resonance and intercombination lines in Mg-like ions of atomic numbersZ=13–92

“…[32][33][34][35][36][37][38][39][40][41][42][43][44][45]) have been applied, but not many have involved the treatment of ions of Z 42 (Mo). Figures 1 and 2 show the isoelectronic trends of some of the calculations in comparison to our own MR-MP approach (which is explained in the next section).…”

“…However, their results progressively deviate from the experimental trend at mid Z, and at high Z, their mismatch exceeds that of the computations by Marques et al [36] Various other computations (not depicted in our figures) scatter in the same wide range as the ones selected for display in our figures. For example, Wang et al [43,44] apply multiconfiguration Dirac-Fock (MCDF) calculations to six Mg-like ion species with Z in the range from 53 to 62. Their 3s3p triplet level results (given for three ion species only) are less than 900 cm −1 away from experiment and thus among the better ones, but their singlet level results deviate from experiment by more than 5000 cm −1 and thus are poorer than, for example, the results obtained by Marques et al [36] some 13 years earlier.…”

Observations and identifications of extreme ultraviolet spectra of Ca-like to Na-like neodymium ions using an electron beam ion trap

“…Further justifications for the identifications of spectral lines from neighboring charge states were provided by the variation of line intensities as a function of electron beam energy. [56,57]; e [52]; f [53]; g [28]; i [50]; j [59]; k [27]; l [49]. To provide a unified scale for comparisons, the measured spectra were normalized to the corresponding beam current and collection time.…”

“…The transitions of Mg-like sequence have been a subject of interest for a long time due to their various applications in fields such as astrophysics, plasma, and thermonuclear fusion research [52]. For Mg-like lines, in pure LS coupling, where the spin-orbit interaction is negligible, the radiative decay into the ground level 3s 2 1 S 0 from the triplet level 3s3p 3 P 1 is forbidden.…”