1. |
- JOHNSON, A, et al.
(författare)
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HIGH-SPIN STUDIES NEAR SN-100 WITH NORDBALL - NEW RESULTS ON IN-102, IN-104 AND SB-108
- 1993
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Konferensbidrag (refereegranskat)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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2. |
- LIDEN, F, et al.
(författare)
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ALIGNMENT PROCESSES IN CS-119, CS-121 AND CS-123
- 1992
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 550:2, s. 365-390
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Tidskriftsartikel (refereegranskat)abstract
- Rotational band structures have been observed in the odd-A Cs isotopes 119Cs, 121Cs and 123Cs. The previously known bands have been extended to higher spin values and several new bands have been established. Alignments of both h11/2 protons and neutrons are seen. Of special interest are the alignment frequencies in the (tentative) [422]3/2+ and [404]9/2+ bands which indicate a configuration-dependent proton pairing. Furthermore, the variation of the interaction strength at the first band crossing in the h11/2 bands does not follow the standard cranked-shell-model predictions. This feature is in line with previous systematic observations of alignment processes in high-j intruder bands, and might infer an additional band mixing due to a neutron-proton interaction.(~)[GRAPHICS]
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3. |
- SEWERYNIAK, D, et al.
(författare)
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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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Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 321:4, s. 323-328
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Tidskriftsartikel (refereegranskat)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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4. |
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5. |
- SEWERYNIAK, D, et al.
(författare)
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IN-BEAM GAMMA-RAY SPECTROSCOPY OF IN-102
- 1993
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 345:2, s. 243-244
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Tidskriftsartikel (refereegranskat)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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6. |
- Cederwall, Bo, et al.
(författare)
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HIGH-SPIN STATES IN BA-121 AND DEFORMATION-DEPENDENT ALIGNMENTS
- 1991
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 529:2, s. 410-428
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Tidskriftsartikel (refereegranskat)abstract
- The high-spin structure of 121Ba has been investigated by in-beam gamma-ray spectroscopic techniques. Rotational bands based on the h11/2, g7/2 and tentatively d5/2 quasineutron configurations have been established. The alignments of h11/2 protons and neutrons are identified at HBAR-omega-c = 0.35-0.40 MeV in the h11/2 and g7/2 bands whereas an alignment occurs at HBAR-omega-c = 0.29 MeV in the (tentatively) d5/2 band. B(M1)/B(E2) ratios were extracted and contributed to the configuration assignments. The results are interpreted within the cranked mean-field approach.
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7. |
- Cederwall, Bo, et al.
(författare)
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HIGH-SPIN STATES OF BA-120
- 1991
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 338:4, s. 461-462
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Tidskriftsartikel (refereegranskat)abstract
- The very neutron deficient nucleus 120Ba has been investigated in a high-spin gamma-spectroscopic study. The yrast band of 120Ba is extended up to spin 22 h and one tentatively assigned negative-parity side band is observed up to spin 15 h. The experimental results are compared with Total Routhian Surface calculations.
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8. |
- Cederwall, Bo, et al.
(författare)
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NEUTRON AND PROTON H11/2 ALIGNMENT EFFECTS IN LA-121
- 1991
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 338:4, s. 463-464
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Tidskriftsartikel (refereegranskat)abstract
- In a gamma-spectroscopic study, excited states in the very neutron deficient nucleus 121La have been established for the first time. Rotational bands build on the 9/2+[404] and 1/2-[550] Nilsson orbitals are observed up to a maximum spin of tentatively 51/2 h. The experimental results are compared with Total Routhian Surface calculations.
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9. |
- Cederwall, Bo, et al.
(författare)
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SIGNATURE INVERSION IN CS-120 - EVIDENCE FOR A RESIDUAL PN INTERACTION
- 1992
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 542:3, s. 454-478
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states have been observed in the odd-odd isotope 120Cs in S-32-induced reactions. The previously known band is extended to higher spin and several new bands are identified. Band-head configurations have been inferred by comparing the band properties with known bands in the odd nuclei 121Cs and 121Ba. A remarkable signature inversion is observed in the pi-h11/2 x nu-h11/2 band. The experimental data are compared with calculations made within the total routhian surface model and the two-particle plus triaxial rotor model. It is concluded that a significant residual pn interaction rather than triaxiality is responsible for the signature inversion phenomenon in the pi-h11/2 x nu-h11/2 band of 120Cs.(~)[GRAPHICS]
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10. |
- 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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