| 1. |
- Caamano, M, et al.
(author)
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Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation
- 2005
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 23:2, s. 201-215
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Journal article (peer-reviewed)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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| 2. |
- Sanchez-Vega, M., et al.
(author)
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Studies of quadrupole collectivity in the γ -soft 106Ru
- 2008
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In: European Physical Journal A. - 1434-6001 .- 1434-601X. ; 35:2, s. 159-165
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Journal article (peer-reviewed)abstract
- Various alternative models were used to describe the structure of 106Ru . For example, the General Collective Model (GCM) predicts shape-coexistence for 106Ru with a spherical and a triaxial minimum and strongly mixed structures, while in the IBA-2 calculations, where 106Ru was considered as transitional from vibrational U(5) to γ -soft O(6) , no need was found to include the shape-coexisting configurations. In order to provide additional constraints on the model interpretations, we have applied the Advanced Time-Delayed (ATD) βγγ(t) method to measure the level lifetimes of the excited levels in 106Ru . The new results include the half-lives of T 1/2 = 183(3) ps and 7.5(30)ps for the 2+ 1 and 2+ 2 states, respectively.
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| 3. |
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| 4. |
- Smith, D. L., et al.
(author)
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Lifetime measurements of the negative-parity 7(-) and 8(-) states in Cd-122
- 2008
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 77:1, s. 014309-
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Journal article (peer-reviewed)abstract
- The Advanced Time-Delayed beta gamma gamma(t) method was used to measure lifetimes of selected high-spin states in Cd-122 populated from beta(-) decay of the J(pi)=(9(-)) isomer in Ag-122. From the gamma gamma coincidences, a new energy level was established at 2616.6 keV with a suggested spin-parity assignment of 8(-). Lifetimes were determined for the high-spin states at 2616.6 and 2502.7 keV as T-1/2=1.35(29) ns and 0.24(6) ns, respectively. The transition rates for gamma rays de-exciting the 7(-) states in the N=74 isotones of Cd-122, Sn-124, and Te-126 were found to be very similar.
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| 5. |
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| 6. |
- Mach, H., et al.
(author)
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New structure information on Mg-30, Mg-31 and Mg-32
- 2005
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In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 25, s. 105-109
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Conference paper (peer-reviewed)abstract
- The fast timing beta gamma gamma(t) method was applied to investigate the level lifetimes in Mg-30,Mg-31,Mg-32. Levels in Mg have been populated in beta and beta-delayed neutron emission of Na, at the ISOLDE facility. From the gamma gamma coincidences a number of new states have been identified and new level schemes were constructed for 30 31,32 Mg. The following preliminary half lives have been determined: T-1/2 = 3.9(4) ns for the 1789 keV state in Mg-30, T-1/2 = 133(8) ps and 10.5(8) us for the 221 keV and 461 keV states in Mg-31, respectively, and T1/2 = 16(4) ps for the 885 keV level in 32Mg. The 1789 keV level was established as a candidate for the intruder 0(+) configuration in Mg-30 with a possible strong E0 branch to the ground state.
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| 7. |
- Mach, Henryk, et al.
(author)
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The single-particle and collective features in the nuclei just above Sn-132
- 2007
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In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1213-1218
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Journal article (peer-reviewed)abstract
- The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sn-134, Sn-135 and Sn-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2(+) state in Sb-135 and its E2 transition to the lower-lying 5/2(+) state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing.
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| 8. |
- Ruchowska, E., et al.
(author)
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Nuclear structure of Th-229
- 2006
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In: Physical Review C. Nuclear Physics. - : American Physical Society. - 0556-2813 .- 1089-490X. ; 73:4
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Journal article (peer-reviewed)abstract
- Lifetimes of excited states in Th-229, populated in the beta decay of Ac-229, have been measured using the advanced time-delayed beta gamma gamma(t) method. Half-lives of 14 states have been determined including 11 of them for the first time. Twenty-seven new gamma lines have been introduced into the beta-decay scheme of Ac-229 based on results of gamma gamma coincidence measurements. Reduced transition probabilities have been determined for more than 70 gamma transitions in Th-229. Average parallel to D-0 parallel to values of 0.029(1), 0.077(3), and 0.024(5) e fm have been deduced for the lowest K-pi=1/2(+/-),3/2(+/-), and 5/2(+/-) parity partner bands, respectively. Excited states in Th-229 and experimental transition rates have been interpreted within the quasiparticle-plus-phonon model. The half-life of the 3.5-eV, 3/2(+) isomeric state is predicted to be about 10 h. Potential energy surfaces on the (beta(2),beta(3)) plane for the lowest single quasiparticle configurations in Th-229 have been calculated using the Strutinsky method.
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| 9. |
- Sanchez-Vega, M., et al.
(author)
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Studies of quadrupole collectivity in the γ -soft 106Ru
- 2008
-
In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 35:2, s. 159-165
-
Journal article (peer-reviewed)abstract
- Various alternative models were used to describe the structure of Ru-106. For example, the General Collective Model (GCM) predicts shape-coexistence for Ru-106 with a spherical and a triaxial minimum and strongly mixed structures, while in the IBA-2 calculations, where Ru-106 was considered as transitional from vibrational U(5) to gamma -soft O(6) , no need was found to include the shape-coexisting configurations. In order to provide additional constraints on the model interpretations, we have applied the Advanced Time-Delayed (ATD) beta gamma gamma(t) method to measure the level lifetimes of the excited levels in Ru-106 . The new results include the half-lives of T-1/2 = 183(3) ps and 7.5(30)ps for the 2(1)(+) and 2(1)(+) states, respectively.
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| 10. |
- Schwerdtfeger, W, et al.
(author)
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Shape Coexistence Near Neutron Number N=20 : First Identification of the E0 Decay from the Deformed First Excited J(pi)=0(+) State in Mg-30
- 2009
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:1, s. 012501-
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Journal article (peer-reviewed)abstract
- The 1789 keV state in Mg-30 was identified as the first excited 0(+) state via its electric monopole (E0) transition to the ground state. The measured small value of rho(2)(E0,0(2)(+)-> 0(1)(+))=(26.2 +/- 7.5)x10(-3) implies within a two-level model a small mixing of competing configurations with largely different intrinsic quadrupole deformation near the neutron shell closure at N=20. Axially symmetric configuration mixing calculations identify the ground state of Mg-30 to be based on neutron configurations below the N=20 shell closure, while the excited 0(+) state mainly consists of two neutrons excited into the nu 1f(7/2) orbital. The experimental result represents the first case where an E0 back decay from a strongly deformed second to the normal deformed first nuclear potential minimum well has been unambiguously identified, thus directly proving shape coexistence at the borderline of the much-debated "island of inversion."
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| 11. |
- Boutami, R., et al.
(author)
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Nuclear structure of Ac-231
- 2008
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In: Nuclear Physics A. - : Elsevier BV. - 0375-9474 .- 1873-1554. ; 811:3-4, s. 244-275
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Journal article (peer-reviewed)abstract
- The low-energy structure of Ac-231 has been investigated by means of gamma ray spectroscopy following the beta(-) decay of Ra-231. Multipolarities of 28 transitions have been established by measuring conversion electrons with a MINI-ORANGE electron spectrometer. The decay scheme of Ra-231 -> Ac-231 has been constructed for the first time. The Advanced Time Delayed beta gamma gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(EI) transition rates derived suggest that the octupole effects., albeit weak, are still present in this exotic nucleus.
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| 12. |
- Boutami, R., et al.
(author)
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Structure of Ac-231 : Measurements of level half-lives
- 2007
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In: European Physical Journal - Special Topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 150:1, s. 87-88
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Journal article (peer-reviewed)abstract
- There is lack of knowledge of the structure of the Ac-231 nucleus located in the upper border of the island of octupole deformation centered around A = 225. We have populated the excited states in Ac-231 by beta-decay from the parent Ra-231 produced at ISOLDE, CERN. The low-energy structure of Ac-231 has been investigated by means of gamma, conversion electrons, gamma-gamma and gamma-e(-) spectroscopy. We report here in the precise determination in Ac-231 of the half-life of the most intensively populated states by the Advanced Time Delayed beta beta gamma(t) technique.
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| 13. |
- Fogelberg, Birger, et al.
(author)
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Neutron separation energies at N=83 and the isomer position in 136I
- 2007
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 75:5, s. 054308-
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Journal article (peer-reviewed)abstract
- New experimental total β-decay energies of 135,136Te and of the two isomers of 136I have been obtained, giving much improved accuracy for the nuclear masses of these nuclides. The neutron separation energies at N=83 were deduced and are compared to recent theoretical and systematic predictions. The new results resolve the problem with the excitation energy of the isomeric state of 136I. Theoretical calculations of the isomer splitting of 136I are in good agreement with the new data.
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| 14. |
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| 15. |
- Kjekshus, John, et al.
(author)
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Rosuvastatin in older patients with systolic heart failure.
- 2007
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In: The New England journal of medicine. - 1533-4406. ; 357:22, s. 2248-61
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Journal article (peer-reviewed)abstract
- BACKGROUND: Patients with systolic heart failure have generally been excluded from statin trials. Acute coronary events are uncommon in this population, and statins have theoretical risks in these patients. METHODS: A total of 5011 patients at least 60 years of age with New York Heart Association class II, III, or IV ischemic, systolic heart failure were randomly assigned to receive 10 mg of rosuvastatin or placebo per day. The primary composite outcome was death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Secondary outcomes included death from any cause, any coronary event, death from cardiovascular causes, and the number of hospitalizations. RESULTS: As compared with the placebo group, patients in the rosuvastatin group had decreased levels of low-density lipoprotein cholesterol (difference between groups, 45.0%; P<0.001) and of high-sensitivity C-reactive protein (difference between groups, 37.1%; P<0.001). During a median follow-up of 32.8 months, the primary outcome occurred in 692 patients in the rosuvastatin group and 732 in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.83 to 1.02; P=0.12), and 728 patients and 759 patients, respectively, died (hazard ratio, 0.95; 95% CI, 0.86 to 1.05; P=0.31). There were no significant differences between the two groups in the coronary outcome or death from cardiovascular causes. In a prespecified secondary analysis, there were fewer hospitalizations for cardiovascular causes in the rosuvastatin group (2193) than in the placebo group (2564) (P<0.001). No excessive episodes of muscle-related or other adverse events occurred in the rosuvastatin group. CONCLUSIONS: Rosuvastatin did not reduce the primary outcome or the number of deaths from any cause in older patients with systolic heart failure, although the drug did reduce the number of cardiovascular hospitalizations. The drug did not cause safety problems. (ClinicalTrials.gov number, NCT00206310.)
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| 16. |
- Mach, H., et al.
(author)
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Application of ultra-fast timing techniques to the study of exotic and weakly produced nuclei
- 2005
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In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. S1421-S1426
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Journal article (peer-reviewed)abstract
- Ultra-fast time-delayed techniques have been recently applied in a number of studies where exotic nuclei were identified using advanced selection techniques. These include large Compton-suppressed Ge arrays, in-flight separators or recoil separators. Some of the new results are discussed in this presentation. Besides the results for Mg-32 and Pd-96, they include the first determination of the half-life of the 8(+) state in Ge-80, T-1/2 = 2.95(6) ns, and significantly more precise results for Mn-51 (3680 keV level) and V-48 (421 keV level), T-1/2 = 1760(40) ps and T-1/2.
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| 17. |
- Mach, Henryk, et al.
(author)
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Structure of heavy Fe nuclei at the point of transition at N simular to 37
- 2009
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In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 40:3, s. 477-480
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Journal article (peer-reviewed)abstract
- We have studied energy levels in Fe-63 populated in the beta-decay of Mn-63. A new (preliminary) level scheme of Fe-63 includes 10 excited states connected by 21 gamma-rays. The first excited states at 357 and 451 keV have the level half-lives of 110 ps and 780 ps, respectively. Three states, at 357, 451, and 1132 keV, are strongly beta-fed with log ft similar to 5, while there is only a very week beta-feeding, if any at all, to the ground state. The new results imply that Fe-63 departs from a simple shell model structure observed for heavier N = 37 isotones of Ni-65 and Zn-67.
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