1. |
- Hinke, C. B., et al.
(author)
-
Superallowed Gamow-Teller decay of the doubly magic nucleus 100Sn
- 2012
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 486:7403, s. 341-345
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Journal article (peer-reviewed)abstract
- The shell structure of atomic nuclei is associated with 'magic numbers' and originates in the nearly independent motion of neutrons and protons in a mean potential generated by all nucleons. During beta(+)-decay, a proton transforms into a neutron in a previously not fully occupied orbital, emitting a positron-neutrino pair with either parallel or antiparallel spins, in a Gamow-Teller or Fermi transition, respectively. The transition probability, or strength, of a Gamow-Teller transition depends sensitively on the underlying shell structure and is usually distributed among many states in the neighbouring nucleus. Here we report measurements of the half-life and decay energy for the decay of Sn-100, the heaviest doubly magic nucleus with equal numbers of protons and neutrons. In the beta-decay of Sn-100, a large fraction of the strength is observable because of the large decay energy. We determine the largest Gamow-Teller strength so far measured in allowed nuclear beta-decay, establishing the 'superallowed' nature of this Gamow-Teller transition. The large strength and the low-energy states in the daughter nucleus, In-100, are well reproduced by modern, large-scale shell model calculations.
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2. |
- Kumar, R., et al.
(author)
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ENHANCED 0(g.s.)(+) -> 2(1)(+) E2 TRANSITION STRENGTH IN Sn-112,Sn-114
- 2011
-
In: Acta Physica Polonica B. - 0587-4254. ; 42:3-4, s. 813-816
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Conference paper (peer-reviewed)abstract
- The poorly known B(E2; 0(+) -> 2(+)) values of Sn-112 and Sn-114 have been measured to high precision. Two Coulomb excitation experiments were performed to determine the reduced transition probabilities relative to Sn-116 in order to minimize the systematic errors. The obtained B(E2 up arrow) values of 0.242(8) e(2)b(2) for Sn-112 and 0.232(8) e(2)b(2) for Sn-114 confirm the tendency of large B(E2 up arrow) values for the lighter tin isotopes below the midshell Sn-116 that has been observed recently in various radioactive ion beam experiments.
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3. |
- Lalkovski, S., et al.
(author)
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Core-coupled states and split proton-neutron quasiparticle multiplets in Ag122-126
- 2013
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 87:3, s. 034308-
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Journal article (peer-reviewed)abstract
- Neutron-rich silver isotopes were populated in the fragmentation of a Xe-136 beam and the relativistic fission of U-238. The fragments were mass analyzed with the GSI Fragment Separator and subsequently implanted into a passive stopper. Isomeric transitions were detected by 105 high-purity germanium detectors. Eight isomeric states were observed in Ag122-126 nuclei. The level schemes of Ag-122,Ag-123,Ag-125 were revised and extended with isomeric transitions being observed for the first time. The excited states in the odd-mass silver isotopes are interpreted as core-coupled states. The isomeric states in the even-mass silver isotopes are discussed in the framework of the proton-neutron split multiplets. The results of shell-model calculations, performed for the most neutron-rich silver nuclei are compared to the experimental data.
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4. |
- Alkhomashi, N., et al.
(author)
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Beta(-)-Delayed And Isomer Spectroscopy Of Neutron-Rich Ta And W Isotopes
- 2009
-
In: Acta Physica Polonica B. - 0587-4254. ; 40:3, s. 875-878
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Conference paper (peer-reviewed)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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5. |
- Alkhomashi, N., et al.
(author)
-
beta(-)-delayed spectroscopy of neutron-rich tantalum nuclei: Shape evolution in neutron-rich tungsten isotopes
- 2009
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:6
-
Journal article (peer-reviewed)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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6. |
- Davies, P. J., et al.
(author)
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The role of core excitations in the structure and decay of the 16(+) spin-gap isomer in Cd-96
- 2017
-
In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 767, s. 474-479
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Journal article (peer-reviewed)abstract
- The first evidence for beta-delayed proton emission from the 16(+) spin gap isomer in Cd-96 is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the BigRIPS spectrometer and the EURICA decay station. beta p branching ratios for the ground state and 16(+) isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of Cd-95. Large scale shell model (LSSM) calculations have been performed and WKB estimates made for l = 0, 2, 4 proton emission from three resonance-like states in Ag-96, that are populated by the beta decay of the isomer, and the results compared to the new data. The calculations suggest that l = 2 proton emission from the resonance states, which reside similar to 5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16(+) state.
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7. |
- Doornenbal, P., et al.
(author)
-
RISING: Gamma‐ray Spectroscopy with Radioactive Beams at GSI
- 2007
-
In: AIP Conference Proceedings. - : AIP. - 0094-243X. - 9780735413283 ; 891, s. 99-107
-
Conference paper (peer-reviewed)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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8. |
- Grawe, H., et al.
(author)
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The (6+) isomer in 102Sn revisited : Neutron and proton effective charges close to the double shell closure
- 2021
-
In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 820
-
Journal article (peer-reviewed)abstract
- In a high-energy fragmentation experiment at GSI an Iπ = (6+) isomer and its γ-decay are identified in 102Sn, the two-neutron neighbour of the doubly-magic 100Sn. Its half-life is measured to be T1/2 = 367(11) ns. The possible existence of further isomers is discussed in the framework of large-scale shell model (LSSM) calculations including up to five particle-hole excitations of the 100Sn core. From the precise B(E2; 6+ → 4+) strength and the recently remeasured value for B(E2; 8+ → 6+) in the two-proton hole neighbour 98Cd effective E2 polarization charges for protons and neutrons were inferred including LSSM corrections within the full N=4 0hω space. The results are discussed in comparison to predicted and empirically determined effective operators.
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9. |
- Haefner, G., et al.
(author)
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Properties of γ-decaying Isomers in the 100Sn Region Revisited
- 2019
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In: Acta Physica Polonica B. - : JAGIELLONIAN UNIV PRESS. - 0587-4254 .- 1509-5770. ; 50:3, s. 431-437
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Journal article (peer-reviewed)abstract
- The study of nuclei in the region around the N = Z doubly-magic nucleus 100Sn has been of long standing interest for the nuclear structure and nuclear astrophysics. Recently, Park et al. have reported on properties of γ-decaying isomers and isomeric ratios in the vicinity of 100Sn. That experiment was performed at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center in Japan as a part of the EURICA campaign. Neutron-deficient nuclei were produced in a fragmentation reaction of a 124Xe primary beam on a 9Be target at an energy of 345 MeV/A. Secondary ions were separated and identified in the BigRIPS fragment separator and implanted in the silicon detector array WAS3ABi. The data presented here were obtained in another experiment performed at the RIBF using the same reaction but slightly different separator settings. New results of ratios of isomeric population and half-lives of γ-decaying isomers populated in the experiment are presented.
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10. |
- Häfner, G., et al.
(author)
-
Properties of γ-decaying isomers in the Sn 100 region populated in fragmentation of a Xe 124 beam
- 2019
-
In: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 100:2
-
Journal article (peer-reviewed)abstract
- A systematic study was performed of microsecond γ-decaying isomers around Sn100 produced in a fragmentation reaction of a Xe124 beam at 345 MeV/u at the Radioactive Ion Beam Factory of the RIKEN Nishina Center in Saitama, Japan. Half-lives of isomeric states in that region were remeasured allowing us to improve the currently available experimental information. Reduced transition probabilities were deduced and compared to shell-model calculations in various model spaces. The recently reported low-energy transitions in Rh92 and Ag96 were remeasured with improved precision. Additionally, experimental information on isomeric ratios, including five new ones, were extracted and compared to a previous experimental study and the sharp cutoff model of fragmentation reaction.
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11. |
- Morales, A. I., et al.
(author)
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beta-delayed gamma-ray spectroscopy of Au-203,Au-204 and Pt200-202
- 2013
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:1
-
Journal article (peer-reviewed)abstract
- The beta decay of five heavy, neutron-rich nuclei, Pt-203,Pt-204 and Ir200-202, has been investigated following relativistic cold fragmentation reactions of lead projectiles using the FRS + RISING setup at GSI. This paper reports on the study of the low-lying states in the decay daughter nuclei Au-203,Au-204 and Pt200-202. The characteristic gamma rays for each nucleus have been determined using beta-delayed gamma-ray spectroscopy. Tentative level schemes, relative intensities, and apparent beta feedings are provided. These data are compared with shell-model calculations, which indicate a substantial contribution to the total beta strength from high-energy first-forbidden beta-decay transitions in this mass region.
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12. |
- Morales, A. I., et al.
(author)
-
beta -Delayed gamma -Ray Spectroscopy of Heavy Neutron Rich Nuclei "South" of Lead
- 2009
-
In: Acta Physica Polonica B. - 0587-4254. ; 40:3, s. 867-870
-
Conference paper (peer-reviewed)abstract
- Relativistic projectile fragmentation of a Pb-208 primary beam has been used to produce neutron-rich nuclei with proton-holes relative to the Z = 82 shell closure, i.e., "south" of Pb. beta-delayed gamma-ray spectroscopy allows to investigate the structural properties of such nuclei with A similar to 195 -> 205. The current work presents transitions de-exciting excited states in Au-204, which are the first spectroscopic information on this N = 125 isotone.
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13. |
- Morales, A I, et al.
(author)
-
Half-Life Systematics across the N=126 Shell Closure: Role of First-Forbidden Transitions in the β Decay of Heavy Neutron-Rich Nuclei.
- 2014
-
In: Physical Review Letters. - 1079-7114. ; 113:2
-
Journal article (peer-reviewed)abstract
- This Letter reports on a systematic study of β-decay half-lives of neutron-rich nuclei around doubly magic ^{208}Pb. The lifetimes of the 126-neutron shell isotone ^{204}Pt and the neighboring ^{200-202}Ir, ^{203}Pt, ^{204}Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden β strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during β decay back to stability.
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14. |
- Moschner, K., et al.
(author)
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Study of ground and excited state decays in N approximate to Z Ag nuclei
- 2015
-
In: CGS15 - CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS. - : EDP Sciences. - 9782759817948
-
Conference paper (peer-reviewed)abstract
- A decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic Sn-100. The N = Z nuclei In-98, Cd-96 and Ag-94 were of particular interest for the present study. Preliminary results on the neutron deficient nuclei Ag-93 and Ag-94 are presented. In Ag-94 a more precise value for the half-life of the ground state's superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Q(beta) values from the measured data. The decay of Ag-93 is discussed based on the observed implantation-decay correlation events.
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15. |
- Naqvi, F., et al.
(author)
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Isomer spectroscopy of (127)Cd
- 2010
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 82:3, s. 034323-
-
Journal article (peer-reviewed)abstract
- The spin and configurational structure of excited states of (127)Cd, the two-proton and three-neutron hole neighbor of (132)Sn, has been studied. An isomeric state with a half-life of 17.5(3) mu s was populated in the fragmentation of a (136)Xe beam on a (9)Be target at a beam energy of 750 MeV/u. Time distributions of the delayed gamma transitions and gamma gamma coincidence relations were exploited to construct a decay scheme. The observed yrast (19/2)(+) isomer is proposed to have dominant configurations of nu(h(11/2)(-3))pi(g(9/2)(-1), p(1/2)(-1)), nu(h(11/2)(-2)d(3/2)(-1))pi(g(9/2)(-2)), and nu(h(11/2)(-2), s(1/2)(-1))pi(g(9/2)(-2)) and to decay by two competing stretched M2 and E3 transitions. Experimental results are compared with the isotone (129)Sn. The new information provides input for the proton-neutron interaction and the evolution of neutron hole energies in nuclei around the doubly magic (132)Sn core.
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16. |
- Podolyak, Zs., et al.
(author)
-
Proton-hole excitation in the closed shell nucleus Au-205
- 2009
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 672:2, s. 116-119
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Journal article (peer-reviewed)abstract
- The neutron-rich N = 126 nucleus Au-205 has been populated following the relativistic energy projectile fragmentation of E/A = 1 GeV Pb-208, and studied via charged-particle decay spectroscopy. An internal decay with a transition energy of 907(5) keV and a half-life of T-1/2 = 6(2) s has been identified through the observation of the corresponding K and L internal conversion electron lines. The 907 keV energy level corresponds to the pi h(11/2)(-1) proton-hole state and decays both internally into the pi d(3/2)(-1) ground-state and via beta decay into Hg-205. The obtained data provides information on the evolution of single-proton hole energies which are vital inputs of shell model descriptions for nuclei around the Pb-208(82)126 doubly magic core. (C) 2009 Elsevier B.V. All rights reserved.
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17. |
- Wimmer, K., et al.
(author)
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First spectroscopy of Ti-61 and the transition to the Island of Inversion at N=40
- 2019
-
In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 792, s. 16-20
-
Journal article (peer-reviewed)abstract
- Isomeric states in Ti-59,Ti-61 have been populated in the projectile fragmentation of a 345 AMeV( 238)U beam at the Radioactive Isotope Beam Factory. The decay lifetimes and delayed gamma-ray transitions were measured with the EURICA array. Besides the known isomeric state in Ti-59, two isomeric states in Ti-61 are observed for the first time. Based on the measured lifetimes, transition multipolarities as well as tentative spins and parities are assigned. Large-scale shell model calculations based on the modified LNPS interaction show that both Ti-59 and Ti-61 belong to the Island of Inversion at N = 40 with ground state configurations dominated by particle-hole excitations to the g(9/2 )and d(5/2) orbits.
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18. |
- Wimmer, K., et al.
(author)
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Isomeric states in neutron-rich nuclei near N=40
- 2021
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In: Physical Review C. - : American Physical Society (APS). - 2469-9985 .- 2469-9993. ; 104:1
-
Journal article (peer-reviewed)abstract
- Neutron-rich nuclei in the vicinity of the N = 40 island of inversion are characterized by shell evolution and exhibit deformed ground states. In several nuclei isomeric states have been observed and attributed to excitations to the intruder neutron 1g(9/2) orbital. In the present paper we searched for isomeric states in nuclei around N = 40, Z = 22 produced by projectile fragmentation at the Radioactive Isotope Beam Factory. Delayed. rays were detected by the Euroball RIKEN Cluster Array germanium detector array gamma High statistics data allowed for an updated decay scheme of V-60. The lifetime of an isomeric state in V-64 was measured for the first time in the present experiment. A previously unobserved isomeric state was discovered in Sc-58. The measured lifetime suggests a parity changing transition, originating from an odd number of neutrons in the 1g(9/2) orbital. The nature of the isomeric state in Sc-58 is, thus, different from isomers in the less exotic V and Sc nuclei.
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19. |
- Caceres, L., et al.
(author)
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Spherical proton-neutron structure of isomeric states in Cd-128
- 2009
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 79:1, s. 011301-
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Journal article (peer-reviewed)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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20. |
- Doornenbal, P., et al.
(author)
-
Enhanced strength of the 2(1)(+) -> 0(g.s.)(+) transition in Sn-114 studied via Coulomb excitation in inverse kinematics
- 2008
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:3
-
Journal article (peer-reviewed)abstract
- The 2(1)(+) states of Sn-114,Sn-116 were excited in two consecutive experiments by means of Coulomb excitation in inverse kinematics on a Ni-58 target. A precise determination of the reduced transition probability B(E2; 0(g.s.)(+) -> 2(1)(+)) of Sn-114 relative to the well-known 2(1)(+) excitation strength in Sn-116 was achieved by comparing the relative projectile to target 2(1)(+) -> 0(g.s.)(+) decay intensities. The obtained B(E2 up arrow) value of 0.232(8)e(2)b(2) for Sn-114 confirms the tendency of large B(E2 up arrow) values for the light tin isotopes below the midshell Sn-116 that has been observed recently in various radioactive ion beam experiments. The result establishes most clearly the discrepancy between the current B(E2 up arrow) value predictions from large-scale shell-model calculations and the experimental deviation, which commences already for the stable Sn-114 isotope.
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21. |
- Farrelly, G. F., et al.
(author)
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Revision of the K-Isomer in 190W
- 2009
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In: 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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Journal article (peer-reviewed)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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22. |
- Garnsworthy, A. B., et al.
(author)
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Isomeric States in Neutron-deficient A~80-90 Nuclei Populated in the Fragmentation of 107Ag
- 2009
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 80:6
-
Journal article (peer-reviewed)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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23. |
- Garnsworthy, A. B., et al.
(author)
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Isomeric States in the Light Tc Isotopes
- 2007
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In: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 38:4, s. 1265-1269
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Journal article (peer-reviewed)abstract
- Preliminary results from the first experiment of the Stopped Beam RISING campaign are presented. The relativistic projectile fragmentation of a 750 MeV/u beam of Ag-107 populated isomeric states in very neutron deficient nuclei at the proton dripline around mass 80-90. Nuclei were unambiguously identified using the FRagment Separator (FRS) and its ancillary detectors located at GSI. The ions produced were slowed down from relativistic energies by means of an Al degrader and implanted in the centre of the high-efficiency Stopped RISING array. This allowed the identification of new excited states in the N = Z = 43 nucleus, Tc-86, populated following the de-excitation of a microsecond isomer. Preliminary results of this analysis, as well as previously unobserved isomeric states in Tc-87,Tc-88. are reported.
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24. |
- Garnsworthy, A B, et al.
(author)
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Neutron-proton pairing competition in N = Z nuclei: Metastable state decays in the proton dripline nuclei Nb-82(41) and Tc-86(43)
- 2008
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In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 660:4, s. 326-330
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Journal article (peer-reviewed)abstract
- The low-lying structures of the self-conjugate (N = Z) nuclei Nb-82(41)41 and Tc-86(43)43 have been investigated using isomeric-decay spectroscopy following the projectile fragmentation of a Ag-107 beam. These represent the heaviest odd-odd N = Z nuclei in which internal decays have been identified to date. The resulting level schemes shed light on the shape evolution along the N = Z line between the doubly-magic systems Ni-56(28) and Sn-100(50) and support a preference for T = 1 states in T-z = 0 odd-odd nuclei at low excitation energies associated with a T = 1 neutron-proton pairing gap. Comparison with Projected Shell Model calculations suggests that the decay in Nb-82 may be interpreted as an isospin-changing K isomer.
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25. |
- Gorska, M., et al.
(author)
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Nuclear Structure far off Stability - RISING Campaigns
- 2007
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In: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 38:4, s. 1219-1228
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Journal article (peer-reviewed)abstract
- Nuclear structure studies at CST attracted recently increased interest for the results of present activities as well as for the future project FAIR. A broad range of physics phenomena can be addressed by high-resolution in-beam gamma-ray spectroscopy experiments with radioactive beams offered within the Rare Isotopes Spectroscopic INvestigation at GSI (RISING) project. It combined the EUROBALL Ge-Cluster detectors, the MINIBALL Ce detectors, the HECTOR-BaF detectors, and the fragment separator FRS. The secondary beams produced at relativistic energies were used for Coulomb excitation or secondary fragmentation experiments to study projectile like nuclei by measuring de-excitation photons. The first results of the "fast beam campaign" is discussed in comparison to various shell model calculations. The discussion focuses on the N = 32, 34 sub-shell closure based on neutron rich Cr isotopes. Alternatively, the relativistic radioactive beams, both in their ground and isomeric states, were implanted and their decay could be investigated. The "stopped beam campaign" has started in October 2005 with a series of g-factor measurements. It continued from February 2006 with the next, configuration and the main goal of identification of new isomers and angular momentum population in fragmentation reactions.
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