| 1. |
- DOMBRADI, Z, et al.
(author)
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IDENTIFICATION AND SPECTROSCOPY OF THE TE-108 NUCLEUS
- 1994
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In: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 350:1, s. 3-4
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Journal article (peer-reviewed)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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| 2. |
- FAHLANDER, C, et al.
(author)
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IN-BEAM SPECTROSCOPY OF TE-110
- 1994
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In: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 577:3-4, s. 773-785
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Journal article (peer-reviewed)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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| 3. |
- JOHNSON, A, et al.
(author)
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HIGH-SPIN STUDIES NEAR SN-100 WITH NORDBALL - NEW RESULTS ON IN-102, IN-104 AND SB-108
- 1993
-
Conference paper (peer-reviewed)abstract
- The NORDBALL detector array has been used in a gamma-ray spectroscopic study of neutron deficient nuclei close to 100Sn. A beam of 270 MeV 58Ni ions was used to bombard a target of Fe-54. Reaction channel separation was achieved with a 4pi charged particle Si-ball together with a 1pi neutron detector wall. Altogether 29 final nuclei were identified and excited states were observed for the first time in 8 of them. The weakest identified channel was 100Cd which represented 4.10(-3) % of the observed total yield. Level schemes Of 102In, 104In and 108Sb constructed from gamma-gamma-particle-coincidence and gamma-gamma-angular correlation analyses are presented. The observed structures are discussed in the framework of the nuclear shell-model. In 108Sb also a deformed, strongly coupled, level sequence is observed. This deformed structure is interpreted as built on a pig9/2(-1)xnuh11/2 configuration in agreement with TRS calculations.
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| 4. |
- KARNY, M, et al.
(author)
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EXCITED-STATES OF I-111 AND THE OBSERVATION OF A 21-NS ISOMER
- 1994
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In: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 350:3, s. 179-180
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Journal article (peer-reviewed)abstract
- Proton rich nuclei close to Sn-100 have been investigated an-beam using the NORDBALL detector array. A beam of 270 MeV Ni-58 was used to bombard a Fe-54 target. Reaction channel separation was achieved with a 4 pi charged particle multi-detector set-up together with a 1 pi neutron detector wall placed in the forward direction. Gamma-ray transitions belonging do the I-111 nucleus were identified for the first time. A level scheme constructed from gamma-gamma-perticle-coincidence analysis is proposed. The level structure is discussed within the framework of the shell model and the systematics of the heavier odd iodine nuclei.
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| 5. |
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| 6. |
- SEWERYNIAK, D, et al.
(author)
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IN-BEAM GAMMA-RAY SPECTROSCOPY OF IN-102
- 1993
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In: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 345:2, s. 243-244
-
Journal article (peer-reviewed)abstract
- Neutron deficient nuclei close to 100Sn have been investigated in-beam by gamma-ray spectroscopic methods using the NORDBALL detector array. A beam of 270 MeV Ni-58 was used to bombard a target of Fe-54. Reaction channel separation was achieved with a 4pi charged particle multi-detector set-up together with a 1pi neutron detector wall placed in the forward direction. Excited states of 102In were identified for the first time. The level scheme constructed from gamma-gamma-particle-coincidence and gamma-gamma-angular correlation analysis is presented. The structure of 102In is discussed and compared to neighboring nuclei in the framework of the nuclear shell-model.
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| 7. |
- SEWERYNIAK, D, et al.
(author)
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IN-BEAM SPECTROSCOPY AT THE PROTON-DRIP LINE - FIRST OBSERVATION OF EXCITED-STATES IN SB-106 AND SB-107
- 1994
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In: Physics Letters B. - 0370-2693 .- 1873-2445. ; 321:4, s. 323-328
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Journal article (peer-reviewed)abstract
- Neutron deficient nuclei close to Sn-100 have been investigated in-beam using the NORDBALL detector array. A target of Fe-54 was bombarded with a beam of Ni-58 at 270 MeV. Evaporation residues were identified by detecting protons and alpha particles in a 4 pi charged particle multi-detector set-up and neutrons in a 1 pi neutron detector wall in coincidence with gamma rays. Excited states of the proton drip line nucleus Sb-106 and of Sb-107 were identified for the first time. The yrast level schemes constructed from gamma-gamma-particle coincidence and gamma-gamma angular correlation analysis are presented and discussed within the framework of the nuclear shell model.
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| 8. |
- Cederwall, Bo, et al.
(author)
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NEW FEATURES OF SUPERDEFORMED BANDS IN HG-194
- 1994
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 72:20, s. 3150-3153
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Journal article (peer-reviewed)abstract
- Two new features of superdeformed (SD) bands in the A almost-equal-to 190 region emerge from a study of Hg-194 with the Gammasphere detector array. A decrease of the dynamic moment of inertia is observed for rotational frequencies HBARomega greater-than-or-equal-to 0.4 MeV, confirming long standing expectations based on mean field calculations with pairing. Evidence for a small staggering in the SD transition energies is also observed, suggesting the presence of terms with fourfold symmetry in the SD Hamiltonian.
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| 9. |
- Cederwall, Bo, et al.
(author)
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NEW OBLATE BAND IN HG-196 WITH QUENCHED M1 STRENGTH
- 1993
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 47:6, s. R2443-R2446
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Journal article (peer-reviewed)abstract
- High-spin states in the nucleUs Hg-196 were populated in the reaction (Os(Be,5n))-Os-192 at a beam energy of 65 MeV. A regular rotational-like DELTAI = 1 band has been observed up to an excitation energy of E* almost-equal-to 8.7 MeV and spin I almost-equal-to 30hBAR. This is the second observation of a band of this character in a mercury isotope. The experimental results are compared with mean field calculations and semiclassical estimates based on the Donau-Frauendorf formalism. The mercury bands show significantly lower B(M1)/B(E2) branching ratios as compared with similar bands in light lead nuclei. This difference may be more readily explained by a difference in single-particle structure rather than by large differences in deformation between the lead and mercury configurations.
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| 10. |
- Cederwall, Martin, 1961, et al.
(author)
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Higher-dimensional loop algebras, non-abelian extensions and p-branes
- 1994
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In: Nucl.Phys.B424 (1994) 97.
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Journal article (peer-reviewed)abstract
- We postulate a new type of operator algebra with a non-abelian extension. This algebra generalizes the Kac-Moody algebra in string theory and the Mickelsson-Faddeev algebra in three dimensions to higher-dimensional extended objects (p-branes). We then construct new BRST operators, covariant derivatives and curvature tensors in the higher-dimensional generalization of loop space.
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