| 1. |
- Banu, A, et al.
(författare)
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108Sn Studied with Intermediate-energy Coulomb Excitation
- 2005
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:6
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Tidskriftsartikel (refereegranskat)abstract
- The unstable neutron-deficient Sn-108 isotope has been studied in inverse kinematics by intermediate-energy Coulomb excitation using the RISING/FRS experimental setup at GSI. This is the highest Z nucleus studied so far with this method. Its reduced transition probability B (E2;0(g.s.)(+)-> 2(1)(+)) has been measured for the first time. The extracted B(E2) value of 0.230(57)e(2) b(2) has been determined relative to the known value in the stable Sn-112 isotope. The result is discussed in the framework of recent large-scale shell model calculations performed with realistic effective interactions. The roles of particle-hole excitations of the Sn-100 core and of the Z=50 shell gap for the E2 polarization are investigated.
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| 2. |
- Becker, F, et al.
(författare)
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Status of the RISING Project at GSI
- 2005
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 25:Suppl 1, s. 719-722
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Tidskriftsartikel (refereegranskat)abstract
- The FRS-RISING set-up at GSI uses secondary radioactive beams at relativistic energies for nuclear structure studies. At GSI the fragmentation or fission of stable primary beams up to U-238 provide secondary beams with sufficient intensity to perform gamma-ray spectroscopy. The RISING set-up is described and results of the first RISING campaign are presented. New experimental methods at relativistic energies are being investigated. Future experiments focus on state-of-the art nuclear structure physics covering exotic nuclei all over the nuclear chart.
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| 3. |
- Bednarczyk, P, et al.
(författare)
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Status of the RISING Project at Relativistic Energies
- 2005
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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. ; 36:4, s. 1235-1244
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Tidskriftsartikel (refereegranskat)abstract
- The RISING project was designed to perform high-resolution gamma-ray spectroscopy with radioactive beams at GSI. Unstable beams were produced by fragmentation of relativistic heavy ion projectiles provided by the SIS synchrotron. The fragment separator FRS was used to select and to focus the exotic fragments at about 100A MeV energy on a secondary target. Various charged particle detectors enabled an event-by-event tracking of the incoming radioactive projectiles and the reaction products, thus allowing for a selection of the nuclei of interest and their velocity vector reconstruction. The gamma-ray detection system consisting of the EUROBALL Cluster Ge detectors and the large volume HECTOR BaF2 detectors measured prompt gamma-radiation from nuclei excited in the secondary target. Despite the huge Doppler shift due to the high recoil velocity (beta approximate to 40%), RISING achieved a gamma-energy resolution below 2%. The paper reviews the present status of the RISING project.
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| 4. |
- Blazhev, A, et al.
(författare)
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High-energy Excited States in 98Cd
- 2010
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- In 98Cd a new high-energy isomeric γ-ray transition was identified, which confirms previous spin-parity assignments and enables for the first time the measurement of the E2 and E4 strength for the two decay branches of the isomer. Preliminary results on the 98Cd high-excitation level scheme are presented. A comparison to shell-model calculations as well as implications for the nuclear structure around 100Sn are discussed.
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| 5. |
- Caamano, M, et al.
(författare)
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Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation
- 2005
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 23:2, s. 201-215
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Tidskriftsartikel (refereegranskat)abstract
- Relativistic projectile fragmentation of Pb-208 has been used to produce isomers in neutron-rich, A approximate to 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in Ta-188, W-190, Re-192, Re-193, Os-195, Ir-197, Ir-198, Pt-200, Pt-201, Pt-202 and Au-203, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for Er-174, Er-175, Hf-185, Re-191, Re-194 and Ir-199. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In Pt-200 and Pt-201. the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics.
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| 6. |
- Gladnishki, KA, et al.
(författare)
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Angular Momentum Population in the Projectile Fragmentation of 238U at 750 MeV/nucleon
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 69:2
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Tidskriftsartikel (refereegranskat)abstract
- A systematic study of the population probabilities of nanosecond and microsecond isomers produced following the projectile fragmentation of U-238 at 750 MeV/nucleon has been undertaken at the SIS/FRS facility at GSI. Approximately 15 isomeric states in neutron-deficient nuclei around A similar to 190 were identified and the corresponding. isomeric ratios determined. The results are compared with a model based on the statistical abrasion-ablation description of relativistic fragmentation and simple assumptions concerning gamma cascades in the final nucleus (sharp cutoff). This model represents an upper limit for the population of isomeric states in relativistic projectile fragmentation. When the decay properties of the states above the isomer are taken into account, as opposed to the sharp cutoff approximation, a good agreement between the experimental and calculated angular momentum population is obtained.
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| 7. |
- Gladnishki, KA, et al.
(författare)
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Isomer spectroscopy in the neutron-deficient lead region following projectile fragmentation
- 2003
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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. ; 34:4, s. 2395-2398
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Tidskriftsartikel (refereegranskat)abstract
- Projectile fragmentation of a 750 MeV/nucleon U-238 beam was used to populate neutron-deficient nuclei around A similar to190. Isomeric states in Hg, Tl, Pb, Bi, and Po isotopes were identified and their lifetimes determined, with the ultimate aim of measuring their isomeric ratios to provide information on the spin population in such reactions.
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| 8. |
- Hammond, G, et al.
(författare)
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Spectroscopy of T=3/2 Mirror Nuclei via Two-step Fragmentation using RISING
- 2005
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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. ; 36:4, s. 1253-1257
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Tidskriftsartikel (refereegranskat)abstract
- Two two-step fragmentation reactions were performed using RISING to populate excited states in A approximate to 50 mirror nuclei near to the proton-drip line, in order to test isospin symmetry. The experiments were designed to observe gamma decays of excited states in the mirror nuclei Ni-53(28)25/Mn-53(25)28, which have a large value of total isospin (T = 3/2). In the continuing off-line analysis, gamma transitions have been observed in Ni-54 indicating that two-step fragmentation is a successful technique for spectroscopic investigations of proton-rich nuclear systems in this mass region.
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| 9. |
- Podolyak, Z, et al.
(författare)
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High Angular Momentum States Populated in Fragmentation Reactions
- 2006
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 632:2-3, s. 203-206
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Tidskriftsartikel (refereegranskat)abstract
- The population of metastable states produced in relativistic-energy fragmentation of a U-238 beam has been measured. For states with angular momentum greater than or similar to 20h, a much higher population than expected has been observed. By introducing a collective component to the generation of angular momentum the experimental data can be understood. This is the first time that a collective degree of freedom has be shown to play a major role in such high-energy collisions. (c) 2005 Elsevier B.V. All rights reserved.
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| 10. |
- Reiter, P, et al.
(författare)
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Future RISING experiments at relativistic energies
- 2005
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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. ; 36:4, s. 1259-1268
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Tidskriftsartikel (refereegranskat)abstract
- The proposed experiments for the first RISING (Rare ISotope INvestigations at GSI) campaign will exploit secondary unstable beams at relativistic energies in the range from 100 MeV/u to 400 MeV/u. The RISING spectrometer will be employed for relativistic Coulomb excitation and for high-resolution gamma-spectroscopy experiments after secondary nucleon removal reactions and secondary fragmentation. New experimental methods for spectroscopy at relativistic energics will be investigated in order to measure nuclear structure observables beside the directly accessible level energies and quadrupole deformations. The future experiments will focus on: Shell structure of unstable doubly magic nuclei and their vicinity, symmetries along the N = Z line and mixed symmetry states, shapes and shape coexistence, collective modes and E1 strength distribution.
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