Home << 1 2 3 4 5 6 7 8 9 10 >> [11–16]
List View
 | 
Citations
 | 
Details
   web
Records
Author Hafner, G. et al; Algora, A.
Title First lifetime investigations of N > 82 iodine isotopes: The quest for collectivity Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 104 Issue 1 Pages 014316 - 18pp
Keywords
Abstract We report on spectroscopic information and lifetime measurements in the neutron-rich I-135,I-137,I-139 isotopes. This is the first lifetime data on iodine isotopes beyond N = 82. Excited states were populated in fast neutron-induced fission of U-238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid nu-ball spectrometer. The level schemes of the I-135,I-137,I-139 isotopes are revised in terms of excited states with up to maximum spin-parity of (33/2(+)), populated for the first time in fast neutron-induced fission. We provide first results on the lifetimes of the (9/2(1)(+)) and (13/2(1)(+)) states in I-137 and I-139, and the (17/2(1)(+)) state in 137I. In addition, we give upper lifetime limits for the (11/2(1)(+)) states in I135-139, the (15/2(1)(+)) state in I-137, the (17/2(1)(+)) state in I-139, and reexamine the (29/2(1)(+)) state in I-137. The isomeric data in I-13(5) are reinvestigated, such as the previously known (15/2(1)(+)) and (23/21) isomers with T-1/2 of 1.64(14) and 4.6(7) ns, respectively, as obtained in this work. The new spectroscopic information is compared to that from spontaneous or thermal-neutron induced fission and discussed in the context of large scale shell-model (LSSM) calculations for the region beyond Sn-132, indicating the behavior of collectivity for the three valence-proton iodine chain with N = 82, 84, 86.
Address [Haefner, G.; Lozeva, R.; Lebois, M.; Jovancevic, N.; Thisse, D.; Wilson, J. N.; Babo, M.; Chakma, R.; Delafosse, C.; Hauschild, K.; Ibrahim, F.; Nemer, J.; Popovitch, Y.; Qi, L.; Ralet, D.; Tocabens, G.; Verney, D.] Univ Paris Saclay, IJCLab, CNRS IN2P3, F-91405 Orsay, France, Email: radomira.lozeva@ijclab.in2p3.fr
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000674546900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4913
Permanent link to this record
 
 
Author Valiente-Dobon, J.J. et al; Gadea, A.; Algora, A.
Title Manifestation of the Berry phase in the atomic nucleus Pb-213 Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 816 Issue Pages 136183 - 5pp
Keywords
Abstract The neutron-rich Pb-213 isotope was produced in the fragmentation of a primary 1 GeV A U-238 beam, separated in FRS in mass and atomic number, and then implanted for isomer decay gamma-ray spectroscopy with the RISING setup at GSI. A newly observed isomer and its measured decay properties indicate that states in Pb-213 are characterized by the seniority quantum number that counts the nucleons not in pairs coupled to angular momentum J = 0. The conservation of seniority is a consequence of a geometric phase associated with particle-hole conjugation, which becomes observable in semi-magic nuclei where nucleons half-fill the valence shell. The gamma-ray spectroscopic observables in Pb-213 are thus found to be driven by two mechanisms, particle-hole conjugation and seniority conservation, which are intertwined through a Berry phase.
Address [Valiente-Dobon, J. J.; Gottardo, A.; de Angelis, G.; Goasduff, A.; Napoli, D. R.; Sahin, E.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: javier.valiente@lnl.infn
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000647421500054 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4820
Permanent link to this record
 
 
Author Hall, O. et al; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Morales, A.I.; Rubio, B.; Tain, J.L.; Tolosa-Delgado, A.
Title beta-delayed neutron emission of r-process nuclei at the N=82 shell closure Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 816 Issue Pages 136266 - 7pp
Keywords beta-delayed neutron emission; r-processimportant
Abstract Theoretical models of beta-delayed neutron emission are used as crucial inputs in r-process calculations. Benchmarking the predictions of these models is a challenge due to a lack of currently available experimental data. In this work the beta-delayed neutron emission probabilities of 33 nuclides in the important mass regions south and south-west of Sn-132 are presented, 16 for the first time. The measurements were performed at RIKEN using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The P-1n values presented constrain the predictions of theoretical models in the region, affecting the final abundance distribution of the second r-process peak at A approximate to 130.
Address [Hall, O.; Davinson, T.; Bruno, C. G.; Griffin, C. J.; Kahl, D.] Univ Edinburgh, Sch Phys & Astron, Edinburgh EH9 3FD, Midlothian, Scotland, Email: oscar.hall@ed.ac.uk
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000647421500016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4819
Permanent link to this record
 
 
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
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 Thesis
Publisher Academic Press Inc Elsevier Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0090-3752 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000647012500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4828
Permanent link to this record
 
 
Author Gombas, J.; DeYoung, P.A.; Spyrou, A.; Dombos, A.C.; Algora, A.; Baumann, T.; Crider, B.; Engel, J.; Ginter, T.; Kwan, E.; Liddick, S.N.; Lyons, S.; Naqvi, F.; Ney, E.M.; Pereira, J.; Prokop, C.; Ong, W.; Quinn, S.; Scriven, D.P.; Simon, A.; Sumithrarachchi, C.
Title beta-decay feeding intensity distributions for Nb-103,Nb-104m Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 103 Issue 3 Pages 035803 - 8pp
Keywords
Abstract The beta decays of Nb-103,Nb-104m were studied with the Summing NaI(Tl) (SuN) detector at the National Superconducting Cyclotron Laboratory. The beta-decay feeding intensity distribution I-beta(E) for each isotope was extracted by measuring gamma rays in coincidence with an emitted electron. The I-beta(E) was extracted via the total absorption spectroscopy technique. The I-beta(E) for each nucleus was compared to predictions made by the quasiparticle random-phase approximation (QRPA) model which is commonly used to calculate beta-decay properties for astrophysical applications. The main goal was to provide experimental data for neutron-rich nuclei, relevant to the astrophysical r process. In addition, the extracted beta-decay feeding intensity distributions can lead to a better understanding of nuclear structure in a region of rapid structure changes around A = 100. Finally, experimental data for Nb-104m are also of interest to antineutrino studies of nuclear reactors.
Address [Gombas, J.; DeYoung, P. A.] Hope Coll, Dept Phys, Holland, MI 49422 USA, Email: gombasja@msu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000627565600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4765
Permanent link to this record
 
 
Author Algora, A.; Tain, J.L.; Rubio, B.; Fallot, M.; Gelletly, W.
Title Beta-decay studies for applied and basic nuclear physics Type Journal Article
Year 2021 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 57 Issue 3 Pages 85 - 28pp
Keywords
Abstract In this reviewwe will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of (a) the decay heat in reactors, important for the safety of present and future reactors and (b) the reactor electron anti-neutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta-decay probabilities free from a systematic error called the Pandemonium effect. The total absorption technique is based on the detection of the. cascades that follow the initial beta decay. For this reason the technique requires the use of calorimeters with very high. detection efficiency. The measurements presented and discussed here were performed mainly at the IGISOL facility of the University of Jyvaskyla (Finland) using isotopically pure beams provided by the JYFLTRAP Penning trap. Examples are presented to show that the results of our measurements on selected nuclei have had a large impact on predictions of both the decay heat and the anti-neutrino spectrum from reactors. Some of the cases involve beta-delayed neutron emission thus one can study the competition between gamma – and neutron-emission from states above the neutron separation energy. The gamma-to-neutron emission ratios can be used to constrain neutron capture (n, gamma) cross sections for unstable nuclei of interest in astrophysics. The information obtained from the measurements can also be used to test nuclear model predictions of half-lives and Pn values for decays of interest in astrophysical network calculations. These comparisons also provide insights into aspects of nuclear structure in particular regions of the nuclear chart.
Address [Algora, A.; Tain, J. L.; Rubio, B.] Univ Valencia, CSIC, IFIC, Paterna, Spain, Email: algora@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000625127600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4754
Permanent link to this record
 
 
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
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 Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000621593100006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4757
Permanent link to this record
 
 
Author Wilson, J.N. et al; Algora, A.
Title Angular momentum generation in nuclear fission Type Journal Article
Year 2021 Publication Nature Abbreviated Journal Nature
Volume 590 Issue 7847 Pages 566-570
Keywords
Abstract When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning(1); this phenomenon has been a mystery in nuclear physics for over 40 years(2,3). The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum(4-12). Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the gamma-ray heating problem in nuclear reactors(13,14), for the study of the structure of neutron-rich isotopes(15,16), and for the synthesis and stability of super-heavy elements(17,18). gamma-ray spectroscopy experiments on the origin of spin in the products of nuclear fission of spin-zero nuclei suggest that the fission fragments acquire their spin after scission, rather than before.
Address [Wilson, J. N.; Thisse, D.; Lebois, M.; Jovancevic, N.; Adsley, P.; Babo, M.; Chakma, R.; Delafosse, C.; Haefner, G.; Hauschild, K.; Ibrahim, F.; Ljungvall, J.; Lopez-Martens, A.; Lozeva, R.; Matea, I; Nemer, J.; Popovitch, Y.; Qi, L.; Tocabens, G.; Verney, D.] Univ Paris Saclay, IJC Lab, CNRS, IN2P3, Orsay, France, Email: jonathan.wilson@ijclab.in2p3.fr
Corporate Author Thesis
Publisher Nature Research Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000621583600006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4717
Permanent link to this record
 
 
Author Wimmer, K. et al; Algora, A.; Rubio, B.
Title Shape Changes in the Mirror Nuclei Kr-70 and Se-70 Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 126 Issue 7 Pages 072501 - 6pp
Keywords
Abstract We studied the proton-rich T-z = -1 nucleus Kr-70 through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2; 0+ -> 2+). Comparison with the other members of the A = 70 isospin triplet, Br-70 and Se-70, studied in the same experiment, shows a 3 sigma deviation from the expected linearity of the electromagnetic matrix elements as a function of T-z. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei Kr-70 and Se-70 contrary to the model predictions.
Address [Wimmer, K.] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: k.wimmer@csic.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000619237200006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4715
Permanent link to this record
 
 
Author Orrigo, S.E A. et al; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A.I.; Agramunt, J.; Guadilla, V.; Montaner-Piza, A.
Title beta decay of the very neutron-deficient Ge-60 and Ge-62 nuclei Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 103 Issue 1 Pages 014324 - 12pp
Keywords
Abstract We report here the results of a study of the beta decay of the proton-rich Ge isotopes, Ge-60 and Ge-62, produced in an experiment at the RIKEN Nishina Center. We have improved our knowledge of the half-lives of Ge-62 [73.5(1) ms] and Ge-60 [25.0(3) ms] and its daughter nucleus, Ga-60 [69.4(2) ms]. We measured individual beta-delayed proton and gamma emissions and their related branching ratios. Decay schemes and absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. A total beta-delayed proton-emission branching ratio of 67(3)% has been obtained for Ge-60. New information has been obtained on the energy levels populated in Ga-60 and on the 1/2(-) excited state in the beta p daughter Zn-59. We extracted a ground state-to-ground state feeding of 85.3(3)% for the decay of Ge-62. Eight new y lines have been added to the deexcitation of levels populated in the Ga-62 daughter.
Address [Orrigo, S. E. A.; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A., I; Agramunt, J.; Guadilla, V; Montaner-Piza, A.] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: sonja.orrigo@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000613141500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4716
Permanent link to this record