| 1. |
- Ekman, Jörgen, et al.
(författare)
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RIS4 : A program for relativistic isotope shift calculations
- 2019
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Ingår i: Computer Physics Communications. - : Elsevier. - 0010-4655 .- 1879-2944. ; 235, s. 433-446
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Tidskriftsartikel (refereegranskat)abstract
- Spectral lines from different isotopes display a small separation in energy, commonly referred to as the line isotope shift. The program RIS4 (Relativistic Isotope Shift) calculates normal and specific mass shift parameters as well as field shift electronic factors from relativistic multiconfiguration Dirac-Hartree-Fock wave functions. These quantities, together with available nuclear data, determine isotope-dependent energy shifts. Using a reformulation of the field shift, it is possible to study, in a model-independent way, the atomic energy shifts arising from changes in nuclear charge distributions, e.g. deformations. (C) 2018 Published by Elsevier B.V.
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| 2. |
- Wang, Kai, et al.
(författare)
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Extended calculations of energy levels, radiative properties, A(J), B-J hyperfine interaction constants, and Lande g(J)-factors for oxygen-like Kr XXIX
- 2017
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Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier. - 0022-4073 .- 1879-1352. ; 194, s. 108-112
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Tidskriftsartikel (refereegranskat)abstract
- Using the multiconfiguration Dirac-Fock method and the second-order many-body perturbation theory method, highly accurate calculations are performed for the lowest 344 fine-structure levels arising from the 2s(2)2p(4), 2s2p(5), 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, 2s(2)2p(3)3d, 2s2p(4)3s, 2s2p(4)3p, 2s2p(4)3d, 2p(5)3s, 2p(5)3p, 2p(5)3d, 2s(2)2p(3)4s, 2s(2)2p(3)4p, 2s(2)2p(3)4d, 2s(2)2p(3)4f, and 2s2p(4)4s configurations in O-like Kr XXIX. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Lande g(J)-factors, and E1, M1, E2, M2 transition rates, line strengths, and oscillator strengths among these 344 levels are obtained. Comparisons are made between our two different sets of results, as well as with the other available experimental and theoretical values. For O-like Kr only a few levels have been experimentally established. The accuracy of our calculated energies is however high enough to facilitate identifications of observed lines involving the n = 3,4 levels. The calculated data are also useful for modeling and diagnosing fusion plasmas. (C) 2017 Elsevier Ltd. All rights reserved.
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| 3. |
- Wang, Kai, et al.
(författare)
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Extended Calculations of Spectroscopic Data : Energy Levels, Lifetimes, and Transition Rates for O-like Ions from Cr XVII to ZnXXIII
- 2017
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Ingår i: Astrophysical Journal Supplement Series. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 0067-0049 .- 1538-4365. ; 229:2
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Tidskriftsartikel (refereegranskat)abstract
- Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the 2 s(2)2p(4), 2s2p(5), 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, 2s(2)2p(3)3d, 2s(2)p(4)3s, 2s2p(4)3p, and 2s2p(4)3d configurations, and multipole (electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2)) transition rates, line strengths, and oscillator strengths among these states are calculated for each O-like ion, from Cr XVII to Zn XXIII. Our two data sets are compared with the National Institute of Standards and Technology and CHIANTI compiled values, and previous calculations. The data are accurate enough for identification and deblending of new emission lines from the Sun and other astrophysical sources. The amount of high-accuracy data is significantly increased for the n. =. 3 states of several O-like ions of astrophysical interest, where experimental data are very scarce.
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