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Energy levels, radiative transition probabilities and autoionization rates for [Cd]4f145p65l'nl, [Cd]4f145p66l''nl, [Cd]4f145p55d2nl, [Cd]4f145p55d6l''nl, [Cd]4f135p65d2nl and [Cd]4f135p65d6l''nl (l' = d, f, g, l'' = s, p, d, l = s, p, d, f, g and n = 5–7) states of Yb-like tungsten (W4 +) are calculated using the relativistic many-body perturbation theory method (RMBPT code), the multiconfiguration relativistic Hebrew University–Lawrence Livermore Atomic Code (HULLAC code) and the Hartree–Fock relativistic method (COWAN code). Branching ratios relative to the [Cd]4f145p65d, [Cd]4f145p66s and [Cd]4f145p66p thresholds in Tm-like tungsten and intensity factors are calculated for satellite lines, and dielectronic recombination (DR) rate coefficients are determined for the singly excited, as well as non-autoionizing core-excited states in Yb-like tungsten. Contributions from the autoionizing doubly excited states [Cd]4f145p65fnl, [Cd]4f145p66l''nl and core-excited [Cd]4f145p55d2nl, [Cd]4f145p55d6l''nl, [Cd]4f135p65d2nl, [Cd]4f135p65d6l''nl states (with n up to 100), which are particulary important for calculating the total DR rates, are estimated. Synthetic dielectronic satellite spectra from Yb-like W are simulated in a broad spectral range from 200 to 1400 Å. These calculations provide recommended values critically evaluated for their accuracy for a number of W4 + properties useful for a variety of applications including for fusion applications. [ABSTRACT FROM AUTHOR]

Radiative lifetimes have been measured for 123 levels of neutral erbium using time-resolved laser-induced fluorescence on a slow beam of erbium atoms. Of the 123 levels, 56 are even parity and range in energy from 26 993 to 40 440 cm[?]1 and 67 are odd parity ranging from 16 070 to 38 401 cm[?]1. This set of Er i lifetimes is much more extensive than others published to date, with 90 of the 123 level lifetimes measured for the first time. These lifetimes will provide the absolute calibration for a large set of measured Er i transition probabilities. Spectroscopic studies of rare earth elements including erbium are motivated by research needs in both the astrophysics and lighting communities. [ABSTRACT FROM AUTHOR]

Two-electron-one-photon (TEOP) M1 and E2 transition energies, line strengths and transition probabilities between the states of the 2p3 and 2s22p odd configurations for B-like ions with 18 [?] Z [?] 92 have been calculated using the GRASP2K package based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Employing active-space techniques to expand the configuration list, we have systematically considered the valence, core-valence and core-core electron correlation effects. Breit interaction and quantum electrodynamical (QED) effects were also included to correct atomic state wavefunctions and the corresponding energies. Influences of electron correlation, Breit interaction and QED effects on transition energies and line strengths of the TEOP M1 and E2 transitions were analysed in detail. The present results were also compared with other theoretical and experimental values. [ABSTRACT FROM AUTHOR]