| 1. |
- Al-Dahan, N., et al.
(författare)
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Isomeric States In 208Hg And 209Tl Populated In Fragmentation Of 238U
- 2009
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 40:3, s. 871-874
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Tidskriftsartikel (refereegranskat)abstract
- The nuclear structure of neutron-rich N > 126 nuclei has been investigated following their production via relativistic projectile fragmentation of a E/A = 1 GeV U-238 beam on a Be target. The preliminary analysis indicates the presence of previously unreported isomeric states in the N = 128 isotones Hg-208 and Tl-209.
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| 2. |
- Al-Dahan, N., et al.
(författare)
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Nuclear Structure "Southeast" of 208Pb: Isomeric states in 208Hg and 209Tl
- 2009
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:6
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Tidskriftsartikel (refereegranskat)abstract
- The nuclear structure of neutron-rich N>126 nuclei has been investigated following their production via relativistic projectile fragmentation of a E/A=1 GeV U-238 beam. Metastable states in the N=128 isotones Hg-208 and Tl-209 have been identified. Delayed gamma-ray transitions are interpreted as arising from the decay of I-pi=(8(+)) and (17/2(+)) isomers, respectively. The data allow for the so far most comprehensive verification of the shell-model approach in the region determined by magic numbers Z < 82 and N>126.
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| 3. |
- Alkhomashi, N., et al.
(författare)
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Beta(-)-Delayed And Isomer Spectroscopy Of Neutron-Rich Ta And W Isotopes
- 2009
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Ingår i: Acta Physica Polonica B. - 0587-4254. ; 40:3, s. 875-878
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Konferensbidrag (refereegranskat)abstract
- Decays of neutron-rich A similar to 190 nuclei have been studied following projectile fragmentation of a Pb-208 beam on a Be-9 target at the GSI Fragment Separator. Gamma-ray decays from previously reported isomeric states in Ta-188, W-190 and (192,193) Re were used as internal calibrations for the particle identification analysis, together with the identification of previously unreported isomeric decays in Ta-189 and W-191. The current work also identifies beta-delayed gamma rays following the decay of Ta-188 to W-188 for the first time.
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| 4. |
- Alkhomashi, N., et al.
(författare)
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beta(-)-delayed spectroscopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes
- 2009
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:6
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Tidskriftsartikel (refereegranskat)abstract
- The low-lying structure of W-188,W-190,W-192 has been studied following beta decays of the neutron-rich mother nuclei Ta-188,Ta-190,Ta-192 produced following the projectile fragmentation of a 1-GeV-per-nucleon Pb-208 primary beam on a natural beryllium target at the GSI Fragment Separator. The beta-decay half-lives of Ta-188, Ta-190, and Ta-192 have been measured, with gamma-ray decays of low-lying states in their respective W daughter nuclei, using heavy-ion beta-gamma correlations and a position-sensitive silicon detector setup. The data provide information on the low-lying excited states in W-188, W-190, and W-192, which highlight a change in nuclear shape at W-190 compared with that of lighter W isotopes. This evolution of ground-state structure along the W isotopic chain is discussed as evidence for a possible proton subshell effect for the A similar to 190 region and is consistent with maximization of the gamma-softness of the nuclear potential around N similar to 116.
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| 5. |
- Bacelar, A. M. Denis, et al.
(författare)
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Angular Momentum Population In Fragmentation Reactions
- 2009
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 40:3, s. 889-892
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Tidskriftsartikel (refereegranskat)abstract
- Neutron-deficient nuclei with N = 126 have been populated following projectile fragmentation of a U-238 beam with energy 1 GeV/A. The decay of several previously reported isomers has been measured. This will allow us to calculate high-spin isomeric ratios and compare them with model calculations to allow a better understanding of the reaction mechanism.
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| 6. |
- Caceres, L. S., et al.
(författare)
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Identification of Excited States in the N = Z Nucleus 82Nb
- 2007
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 38:4, s. 1271-1275
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Tidskriftsartikel (refereegranskat)abstract
- Information on the first excited states in the N = Z = 41 nucleus Nb-82 sheds light on the competition of isospin T = 0 and T = 1 states in the A similar to 80 region. The measurement was performed at the GSI laboratory using fragmentation of a Ag-107 primary beam at 750 MeV/u on a 4 g/cm(2) Be-9 target. The fragments were separated and identified unambiguously in the FRagment Separator. Three excited states were observed and the half-life estimate for the isomeric state was extracted. A tentative spin assignment based on the isobaric analogue states systematics in the T-z = 1 nucleus Zr-82, and transition probabilities indicate T = 1 character of the first two excited states, and T = 0 for the isomeric state.
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| 7. |
- Caceres, L., et al.
(författare)
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Spherical proton-neutron structure of isomeric states in Cd-128
- 2009
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 79:1, s. 011301-
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Tidskriftsartikel (refereegranskat)abstract
- The gamma-ray decay of isomeric states in the even-even nucleus Cd-128 has been observed. The nucleus of interest was produced both by the fragmentation of Xe-136 and the fission of U-238 primary beams. The level scheme was unambiguously constructed based on.. coincidence relations in conjunction with detailed lifetime analysis employed for the first time on this nucleus. Large-scale shell-model calculations, without consideration of excitations across the N = 82 shell closure, were performed and provide a consistent description of the experimental level scheme. The structure of the isomeric states and their decays exhibit coexistence of proton, neutron, and strongly mixed configurations due to p. interaction in overlapping orbitals for both proton and neutron holes.
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| 8. |
- Doornenbal, P., et al.
(författare)
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RISING: Gamma‐ray Spectroscopy with Radioactive Beams at GSI
- 2007
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Ingår i: AIP Conference Proceedings. - : AIP. - 0094-243X. - 9780735413283 ; 891, s. 99-107
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Konferensbidrag (refereegranskat)abstract
- The Rare Isotope Spectroscopic INvestigation at GSI (RISING) project is a major pan‐European collaboration. Its physics aims are the studies of exotic nuclear matter with abnormal proton‐to‐neutron ratios compared with naturally occurring isotopes. RISING combines the FRagment Separator (FRS) which allows relativistic energies and projectile fragmentation reactions with EUROBALL Ge Cluster detectors for γ spectroscopic research. The RISING setup can be used in two different configurations. Either the nuclei of interest are investigated after being stopped or the heavy ions hit a secondary target at relativistic energies and the thereby occurring excitations are studied. For the latter case, MINIBALL Ge detectors and the HECTOR array are used in addition. Example achievements of the Fast Beam setup are presented and compared to various shell model calculations, while for the Stopped Beam setup initial results are shown.
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| 9. |
- Farrelly, G. F., et al.
(författare)
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Revision of the K-Isomer in 190W
- 2009
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 40:3, s. 885-888
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Tidskriftsartikel (refereegranskat)abstract
- Gamma rays from the decay of an isomer in W-190(116) have been observed following projectile fragmentation of a 1 GeV per nucleon Pb-208 beam. An earlier experiment indicated decay from a (10(-)) isomer to the ground state rotational band. Improved statistics have enabled gamma coincidence and time-difference measurements to be made which alter the previous interpretation. Blocked BCS calculations have also been used together with reduced hindrance factors to indicate possible values of spin-parity for the isomer.
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| 10. |
- Garnsworthy, A. B., et al.
(författare)
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Isomeric States in Neutron-deficient A~80-90 Nuclei Populated in the Fragmentation of 107Ag
- 2009
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:6
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Tidskriftsartikel (refereegranskat)abstract
- The relativistic projectile fragmentation of a 750 MeV per nucleon beam of Ag-107 was used to populate isomeric states in neutron-deficient nuclei around A=80-90. Reaction products were separated and unambiguously identified using the GSI FRagment Separator (FRS) and its ancillary detectors. At the final focal plane, the fragments were slowed from relativistic energies by means of an aluminium degrader and implanted in a passive stopper in the center of the high-efficiency, high-granularity Stopped Rare Isotope Spectroscopic INvestigation at GSI (RISING) germanium array. This allowed the identification of excited states in the N=Z nuclei Tc-86(43) and, for the first time, Nb-82(41). Isomeric states have also been identified for the first time in Tc-87,Tc-88, and a previously unreported isomer was observed in Nb-84. Experimental results are presented along with a discussion on the structure of these nuclei based on interpretations provided by several theoretical models.
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