| 1. |
- Rudolph, D., et al.
(författare)
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Experimental and shell-model study of excited states in 55Fe29 and related notes on 55Cu26
- 2021
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 104:4
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 32S+28Si at 125-MeV beam energy was used to populate excited states in 55Fe. Combining the Gammasphere spectrometer with ancillary devices including the Microball CsI(Tl) array and a shell of neutron detectors, a comprehensive level scheme could be derived. The experimental results are compared with theoretical results from shell-model calculations. Taking into account isospin-symmetry breaking terms is found to considerably improve the shell-model description for 55Fe. This motivated a predictive case study of near-yrast states in the mirror nucleus 55Cu.
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| 2. |
- Rudolph, D., et al.
(författare)
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Low-, medium-, and high-spin states in the N=Z+1 nucleus 63Ga
- 2021
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 103:3
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 28Si+40Ca at 122 MeV beam energy was used to populate excited states in the N=Z+1 nucleus 63Ga. With the combination of the Gammasphere spectrometer and the Microball CsI(Tl) charged-particle detector array, the level scheme of 63Ga was extended by more than a factor of two in terms of number of γ-ray transitions and excited states, excitation energy (Ex>30 MeV), and angular momentum (I>30 ℏ). Nine regular sequences of states were newly established in the high-spin part of the level scheme. The majority of these rotational band structures could be connected to the previously known part of the level scheme by high-energy γ-ray transitions in the energy range Eγ=4–6 MeV. Low-spin states were assessed by shell-model calculations. The high-spin rotational bands were interpreted and classified by means of cranked Nilsson-Strutinsky calculations.
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| 3. |
- Rudolph, D., et al.
(författare)
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Onset of high-spin rotational bands in the N=Z nucleus 62Ga
- 2020
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985. ; 102:1
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 28Si + 40Ca at 122 MeV beam energy was used to populate high-spin states in the odd-odd N = Z nucleus 62Ga. With the combination of the Gammasphere spectrometer and the Microball CsI(Tl) charged-particle detector array the decay scheme of 62Ga was extended beyond 10 MeV excitation energy. The onset of band structures was observed. These high-spin rotational states are interpreted and classified by means of cranked Nilsson-Strutinsky calculations.
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| 4. |
- Rudolph, D., et al.
(författare)
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Single-particle and collective excitations in the N=28 isotones 54Fe and 53Mn
- 2020
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985. ; 102:1
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 32S + 28Si at 125 MeV beam energy was used to populate high-spin states in the semimagic N = 28 nuclei 53Mn and 54Fe. With a combination of the Gammasphere spectrometer and ancillary devices including the Microball CsI(Tl) array, extensive high-spin level schemes are derived. They exhibit rotational-like collective structures and competing single-particle excitations. The experimental results are compared with predictions from shell-model calculations, for which the inclusion of isopin-symmetry-breaking terms is found to improve the description. An interpretation of the high-spin states is put forward using cranked Nilsson-Strutinsky calculations, indicative of contributions from collective excitations beyond some 8-MeV excitation energy and highlighting the importance of the g9/2 intruder orbital in this energy range.
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| 5. |
- Mukai, M., et al.
(författare)
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In-gas-cell laser resonance ionization spectroscopy of Ir-196,Ir-197,Ir-198
- 2020
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 102:5
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Tidskriftsartikel (refereegranskat)abstract
- Hyperfine structure (HFS) measurements of neutron-rich iridium isotopes Ir-196,Ir-197,Ir-198 (Z = 77, N = 119-121) were performed via in-gas-cell laser resonance ionization spectroscopy at the KEK Isotope Separation System. Magnetic dipole moments mu and isotope shifts were determined from the HFS spectra. The variation of mean-square charge radii and quadrupole deformation parameters of these isotopes were evaluated from the isotope shifts. The mu value of (197)h, agreed with a theoretical value based on the strong coupling model, and the Ir nucleus was interpreted as prolately deformed by the theoretical calculations. The mu values of Ir-196,Ir-198 were also compared with semiempirical values calculated based on the strong coupling model. From the comparison, we can suggest the possible spin values of I-pi = 1,2(-) for Ir-196 and I-pi = 1(-) for Ir-198.
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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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