Records |
Author |
Das, B. et al; Algora, A. |
Title |
Nature of seniority symmetry breaking in the semimagic nucleus Ru-94 |
Type |
Journal Article |
Year |
2022 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
105 |
Issue |
3 |
Pages |
L031304 - 6pp |
Keywords |
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Abstract |
Direct lifetime measurements via gamma -gamma coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N = 50) nucleus Ru-94. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in Ru-94 were populated primarily via the beta-delayed proton emission of Pd-95 nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon Xe-124 beam impinging on a 4 g/cm(2) Be-9 target. While the deduced E2 strength for the 2(+) -> 0(+) transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4(+) -> 2(+) transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the f pg proton hole space with respect to doubly magic Sn-100. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority v = 2, I-pi = 4(+) state and that of a close-lying v = 4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6(+) -> 4(+) transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations. |
Address |
[Das, B.; Cederwall, B.; Qi, C.; Aktas, O.; Vasiljevic, J.] KTH Royal Inst Technol, S-10691 Stockholm, Sweden, Email: bdas@kth.se; |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9985 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000782895300004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5199 |
Permanent link to this record |
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Author |
Denis Bacelar, A.M. et al; Algora, A.; Molina, F.; Rubio, B. |
Title |
The population of metastable states as a probe of relativistic-energy fragmentation reactions |
Type |
Journal Article |
Year |
2013 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
723 |
Issue |
4-5 |
Pages |
302-306 |
Keywords |
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Abstract |
Isomeric ratios have been measured for high-spin states in Po-198,200,206,208(84), At-208,209,210,211(85), Rn-210,211,212,213,214(86), Fr-208,211,212,213,214(87), Ra-210,211,212,214,215(88), and Ac-215(89) following the projectile fragmentation of a 1 AGeV U-238 beam by a Be-9 target at GSI Helmholtzzentrum fur Schwerionenforschung. The fragments were separated in the fragment separator (FRS) and identified by means of energy loss and time-of-flight techniques. They were brought to rest at the centre of the RISING gamma-ray detector array and intensities of gamma rays emitted in the decay of isomeric states with half-lives between 100 ns and 40 μs and spin values up to 55/2 (h) over bar were used to obtain the corresponding isomeric ratios. The data are compared to theoretical isomeric ratios calculated in the framework of the abrasion-ablation model. Large experimental enhancements are obtained for high-spin isomers in comparison to expected values. |
Address |
[Bacelar, A. M. Denis; Bruce, A. M.; Lalkovski, S.] Univ Brighton, Sch Comp Engn & Math, Brighton BN2 4GJ, E Sussex, England, Email: alison.bruce@brighton.ac.uk |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000320745400005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1502 |
Permanent link to this record |
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Author |
Deo, A.Y.; Podolyak, Z.; Walker, P.M.; Algora, A.; Rubio, B.; Agramunt, J.; Fraile, L.M.; Al-Dahan, N.; Alkhomashi, N.; Briz, J.A.; Estevez, E.; Farrelly, G.; Gelletly, W.; Herlert, A.; Koster, U.; Maira, A.; Singla, S. |
Title |
Structures of Po-201 and Rn-205 from EC/beta(+)-decay studies |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
81 |
Issue |
2 |
Pages |
024322 - 8pp |
Keywords |
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Abstract |
Several low-lying excited states in Rn-205(86)119 and Po-201(84)117 were identified for the first time following EC/beta(+) decay of Fr-205 and At-201, respectively, using gamma-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/beta(+) branch from Fr-205 was measured to be 1.5(2)%. The excited states of the daughter nuclei are understood in terms of the odd nucleon coupling to the neighboring even-even core. The neutron single-particle energies of the p(3/2) orbital relative to the f(5/2) ground state in Rn-205, and the f(5/2) orbital relative to the p(3/2) ground state in Po-201, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a 13/2(+) isomeric level at 657.1(5) keV in Rn-205. The systematic behavior of the 13/2(+) and 3/2(-) levels is also discussed. |
Address |
[Deo, A. Y.; Podolyak, Zs.; Walker, P. M.; Al-Dahan, N.; Alkhomashi, N.; Farrelly, G.; Gelletly, W.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England, Email: A.Deo@surrey.ac.uk |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000278341300001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
431 |
Permanent link to this record |
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Author |
Dimitriou, P. et al; Tain, J.L.; Algora, A. |
Title |
Development of a Reference Database for Beta-Delayed Neutron Emission |
Type |
Journal Article |
Year |
2021 |
Publication |
Nuclear Data Sheets |
Abbreviated Journal |
Nucl. Data Sheets |
Volume |
173 |
Issue |
|
Pages |
144-238 |
Keywords |
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Abstract |
Beta-delayed neutron emission is important for nuclear structure and astrophysics as well as for reactor applications. Significant advances in nuclear experimental techniques in the past two decades have led to a wealth of new measurements that remain to be incorporated in the databases. We report on a coordinated effort to compile and evaluate all the available beta-delayed neutron emission data. The different measurement techniques have been assessed and the data have been compared with semi-microscopic and microscopic-macroscopic models. The new microscopic database has been tested against aggregate total delayed neutron yields, time-dependent group parameters in 6-and 8-group re-presentation, and aggregate delayed neutron spectra. New recommendations of macroscopic delayed-neutron data for fissile materials of interest to applications are also presented. |
Address |
[Dimitriou, P.; Verpelli, M.] IAEA, NAPC Nucl Data Sect, A-1400 Vienna, Austria, Email: p.dimitriou@iaea.org |
Corporate Author |
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Thesis |
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Publisher |
Academic Press Inc Elsevier Science |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0090-3752 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000647012500006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4828 |
Permanent link to this record |
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Author |
Dombos, A.C. et al; Algora, A. |
Title |
Total absorption spectroscopy of the beta decay of Zr-101,102 and Tc-109 |
Type |
Journal Article |
Year |
2021 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
103 |
Issue |
2 |
Pages |
025810 - 20pp |
Keywords |
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Abstract |
The beta decay of Zr-101,Zr-102 and Tc-109 was studied using the technique of total absorption spectroscopy. The experiment was performed at the National Superconducting Cyclotron Laboratory using the Summing NaI(Tl) (SuN) detector in the first-ever application of total absorption spectroscopy with a fast beam produced via projectile fragmentation. The beta-decay feeding intensity and Gamow-Teller transition strength distributions were extracted for these three decays. The extracted distributions were compared to three different quasiparticle random-phase approximation (QRPA) models based on different mean-field potentials. A comparison with calculations from one of the QRPA models was performed to learn about the ground-state shape of the parent nucleus. For Zr-101 and Zr-102, calculations assuming a pure shape configuration (oblate or prolate) were not able to reproduce the extracted distributions. These results may indicate that some type of mixture between oblate and prolate shapes is necessary to reproduce the extracted distributions. For Tc-109, a comparison of the extracted distributions with QRPA calculations suggests a dominant oblate configuration. The other two QRPA models are commonly used to provide beta-decay properties in r-process network calculations. This work shows the importance of making comparisons between the experimental and theoretical beta-decay distributions, rather than just half-lives and beta-delayed neutron emission probabilities, as close to the r-process path as possible. |
Address |
[Dombos, A. C.; Spyrou, A.; Naqvi, F.; Quinn, S. J.; Liddick, S. N.; Baumann, T.; Crider, B. P.; Ginter, T.; Lyons, S.; Ong, W-J; Palmisano, A.; Pereira, J.; Prokop, C. J.; Smith, M. K.] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA, Email: adombos@nd.edu |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9985 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000621593100006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4757 |
Permanent link to this record |