| 1. |
- Juutinen, S, et al.
(författare)
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Coexistence of collective and quasiparticle structures in Sn-106 and Sn-108
- 1997
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 617:1, s. 74-90
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Tidskriftsartikel (refereegranskat)abstract
- New levels in the neutron deficient nuclei Sn-106 and Sn-108 have been investigated by using the NORDBALL detector array combined with charged particle and neutron detectors. The excited structures are discussed in terms of collectivity and the shell model. The excitations are interpreted to be based on d5/2, g7/2 and h(11/2) both for protons and neutrons and g(9/2) for protons. The systematical behaviour of the specific states in the Sn isotopes is studied in the mass range of A = 106-118.
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| 2. |
- Juutinen, S, et al.
(författare)
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Coexistence of collective and quasiparticle structures in Sn-106 and Sn-108
- 1997
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Ingår i: NUCLEAR PHYSICS A. - : ELSEVIER SCIENCE BV. - 0375-9474. ; 617:1, s. 74-90
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- New levels in the neutron deficient nuclei Sn-106 and Sn-108 have been investigated by using the NORDBALL detector array combined with charged particle and neutron detectors. The excited structures are discussed in terms of collectivity and the shell mode
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| 3. |
- Kownacki, J, et al.
(författare)
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High-spin studies of the neutron deficient nuclei In-103, In-105, In-107, and In-109
- 1997
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 627:2, s. 239-258
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states of the isotopes 103,105,107,109In have been investigated using in-beam γ-ray spectroscopic methods. Results from three different experiments are presented. Targets of 54Fe, 50Cr, and 92Mo were bombarded by a 270 and 261 MeV 58Ni beam and by a 95 MeV 19F beam, respectively. Reaction channel separation was achieved with a charged-particle detector array and in the first two experiments also with a 1π neutron detector system. As a result of these experiments the level schemes of 103,105,107,109In were significantly extended. Excited states of these odd-A indium isotopes are discussed within the framework of the nuclear shell model and the hole-core coupling scheme. The systematics of excited states of light odd-A indium isotopes is also discussed.
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| 4. |
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| 5. |
- CEDERKALL, J, et al.
(författare)
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1ST OBSERVATION OF EXCITED-STATES IN SB-108
- 1995
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 581:1, s. 189-204
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Tidskriftsartikel (refereegranskat)abstract
- A spectroscopic study of Sb-108 has been carried out as a part of a larger experiment where in total twenty-nine different residual nuclei were identified. This study gives the first information on excited levels in this nucleus. A low-lying two-quasi-particle multiplet together with some of the higher lying levels are discussed within the framework of the nuclear shell model. A rotational, strongly coupled, band is identified as, most likely, being built on the deformed pig9/2(-1) nuh11/2 configuration in accordance with total routhian surface calculations. Tentative spins and parities are presented as well as B(M1)/B(E2) ratios for some of the transitions in the strongly coupled band.
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| 6. |
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| 7. |
- Cederwall, Bo, et al.
(författare)
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Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 469:7328, s. 68-71
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Tidskriftsartikel (refereegranskat)abstract
- Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.
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| 8. |
- DOMBRADI, Z, et al.
(författare)
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HIGH-SPIN SPECTROSCOPY OF TE-109
- 1995
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 51:5, s. 2394-2399
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Tidskriftsartikel (refereegranskat)
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| 9. |
- DOMBRADI, Z, et al.
(författare)
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IDENTIFICATION AND SPECTROSCOPY OF THE TE-108 NUCLEUS
- 1994
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 350:1, s. 3-4
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Tidskriftsartikel (refereegranskat)abstract
- Excited states of Te-108 were populated in the Fe-54 + Ni-58 (270 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction channel separation. Gamma rays belonging to the neutron deficient nucleus Te-108 were identified for the first time. On the basis of gammagamma-coincidence and angular correlation relations a level scheme was constructed with tentative spin and parity assignments. The structure of the nucleus is discussed in the framework of systematics of heavier Te nuclei.
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| 10. |
- FAHLANDER, C, et al.
(författare)
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IN-BEAM SPECTROSCOPY OF TE-110
- 1994
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 577:3-4, s. 773-785
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Tidskriftsartikel (refereegranskat)abstract
- The neutron-deficient nucleus Te-110 has been investigated by in-beam spectroscopic methods using the NORDBALL multi-detector array. Except for the energy of one level observed in alpha-decay, excited states in Te-110 were previously unknown. The level scheme constructed from gamma gamma-coincidence relationships is presented with tentative spin assignments up to I-pi = 21(-). Above spin 8(+) the yrast states have negative parity. They are most likely the members of a band predominantly based on the nu(h(11/2)g(7/2)) two-quasiparticle configuration. A band crossing is observed at I-pi approximate to 17(-). It is suggested to be caused by the alignment of two h(11/2) neutrons. The cranked shell model correctly predicts the spin alignment, but fails to reproduce the observed band crossing frequency, possibly because of octupole effects.
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