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Author Yokoyama, R. et al; Tain, J.L.; Algora, A.; Agramunt, J.; Domingo-Pardo, C.; Morales, A.I.; Rubio, B.; Tolosa-Delgado, A.
Title Strong one-neutron emission from two-neutron unbound states in beta decays of the r-process nuclei Ga-86,Ga-87 Type Journal Article
Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 100 Issue (up) 3 Pages 031302 - 6pp
Keywords
Abstract beta-delayed one-neutron and two-neutron branching ratios (P-1n and P-2n) have been measured in the decay of A = 84 to 87 Ga isotopes at the Radioactive-Isotope Beam Factory (RIBF) at the RIKEN Nishina Center using a high-efficiency array of He-3 neutron counters (BRIKEN). Two-neutron emission was observed in the decay of Ga-84,Ga-85,Ga-87 for the first time and the branching ratios were measured to be P-2n = 1.6(2)%, 1.3(2)%, and 10.2(28)(stat)(5)(sys)%, respectively. One-neutron branching ratio of Ga-87 (P-1n = 81(9)(stat)(8)(sys)%) and half-life of 29(4) ms were measured for the first time. The branching ratios of Ga-86 were also measured to be P-1n = 74(2)(stat)(8)(sys)% and 16.2(9)(stat)(6)(sys)% with better precision than a previous study. The observation that P-1n > P-2n for both Ga-86,Ga-87 was unexpected and is interpreted as a signature of dominating one-neutron emission from the two-neutron unbound excited states in Ge-86,Ge-87. In order to interpret the experimental results, shell-model and Hauser-Feshbach statistical model calculations of delayed particle and gamma-ray emission probabilities were performed. This model framework reproduces the experimental results. The shell model alone predicts P-2n significantly larger than P-1n for the Ga-87 decay, and it is necessary to invoke a statistical description to successfully explain the observation that P-1n > P-2n. Our new results demonstrate the relevance and importance of a statistical description of neutron emission for the prediction of the decay properties of multineutron emitters and that it must be included in the r-process modeling.
Address [Yokoyama, R.; Grzywacz, R.; Rasco, B. C.; Brewer, N.; Heideman, J.; King, T. T.; Madurga, M.; Singh, M.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA, Email: ryokoyam@utk.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 WOS:000486641000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4145
Permanent link to this record
 
 
Author Fujita, H. et al; Algora, A.; Estevez-Aguado, E.; Molina, F.; Rubio, B.
Title Experimental study of Gamow-Teller transitions via the high-energy-resolution O-18(He-3, t)F-18 reaction: Identification of the low-energy “super” -Gamow-Teller state Type Journal Article
Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 100 Issue (up) 3 Pages 034618 - 13pp
Keywords
Abstract Using the high-resolution O-18(He-3, t)F-18 reaction at 0 degrees and at 140 MeV/nucleon, Gamow-Teller (GT) transitions were studied. A high energy resolution of 31 keV was achieved by applying dispersion matching techniques. The main part of the observed GT transition strength is concentrated in the transition to the F-18 ground state (g.s.). The absolute values of the reduced GT transition strengths, B(GT), were derived up to E-x = 12 MeV assuming proportionality between the B(GT) values and the reaction cross sections at 0 degrees. The B(GT) value obtained from the beta decay of F-18 (g.s.) -> O-18 (g.s.) was used to determine the proportionality constant. A total B(GT) of 4.06(5) was found and 76(1)% of the strength is concentrated to the ground state of F-18. The obtained B(GT) values were compared with those from the O-18(p, n) F-18 reaction and the mirror symmetric beta(+) decay of Ne-18 -> F-18. The candidates for 1(+) states with isospin T = 1 were identified by comparison with the O-18(p, p') data. The results of shell-model and quasiparticle-random-phase approximation calculations suggest constructive contributions of various configurations to the F-18 ground state, suggesting that this state is the low-energy super GT state.
Address [Fujita, H.; Fujita, Y.; Adachi, T.; Hatanaka, K.; Hirota, K.; Ishikawa, D.; Matsubara, H.; Okamura, H.; Ong, H. J.; Susoy, G.; Suzuki, T.; Tamii, A.; Zenihiro, J.] Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan, Email: hfujita@rcnp.osaka-u.ac.jp
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 WOS:000488259800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4165
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 (up) 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 WOS:000625127600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4754
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 (up) 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 WOS:000627565600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4765
Permanent link to this record
 
 
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 (up) 3 Pages L031304 - 6pp
Keywords
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 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 WOS:000782895300004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5199
Permanent link to this record
 
 
Author Moreno, O.; Sarriguren, P.; Algora, A.; Fraile, L.M.; Orrigo, S.E.A.
Title Bulk and decay properties of neutron-deficient odd-mass Hg isotopes near A=185 Type Journal Article
Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 106 Issue (up) 3 Pages 034317 - 11pp
Keywords
Abstract Ground and isomeric states of the neutron-deficient odd-A isotopes 183Hg, 185Hg, and 187Hg are described from a microscopic calculation based on a self-consistent, axially deformed Hartree-Fock mean field with the Skyrme functional and pairing within BCS approximation. For each equilibrium shape and different odd-neutron states, results on mean-square charge radii and magnetic dipole moments are given and analyzed in the context of their sensitivity to the nuclear deformation and to the spin and parity. Spin-isospin correlations within proton-neutron quasiparticle random phase approximation are then introduced in the nuclear states to obtain the distributions of Gamow-Teller strength and the beta+/EC half-lives of these isotopes, whose measurements are planned at ISOLDE-CERN using total absorption gamma-ray spectroscopy techniques.
Address [Moreno, O.; Fraile, L. M.] Univ Complutense Madrid, Dept Estruct Mat Fis Term & Elect, Grp Fis Nucl, Av Complutense s-n, E-28040 Madrid, Spain, Email: osmoreno@ucm.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 WOS:000861758100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5368
Permanent link to this record
 
 
Author Sohler, D. et al; Algora, A.
Title High-spin structure of Pd-104 Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue (up) 4 Pages 044303 - 13pp
Keywords
Abstract The high-spin structure of the nucleus Pd-104 was studied through the Zr-96(C-13,5n) reaction at incident energies of 51 and 58MeV, using the Euroball IV gamma-ray spectrometer in conjunction with the DIAMANT charged-particle array. Several new medium- and high-spin bands were revealed. The already known positive-parity yrast and the negative-parity cascades were extended up to E-x similar to 13, similar to 11, and similar to 9 MeV with I-pi = (26(+)), I-pi = (23(-)), and (20(-)), respectively. The deduced band structures were compared with Woods-Saxon total Routhian surface (TRS) calculations. In addition, non-yrast low-lying positive-parity bands were identified, which were assigned to soft gamma-vibrational excitations.
Address [Sohler, D.; Kuti, I.; Timar, J.; Molnar, J.; Algora, A.; Dombradi, Zs; Gal, J.; Kalinka, G.; Krasznahorkay, A.; Nyako, B. M.; Zolnai, L.] Inst Nucl Res, H-4001 Debrecen, Hungary
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000302237400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 972
Permanent link to this record
 
 
Author Jordan, D. et al; Algora, A.; Tain, J.L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A.B.; Molina, F.; Caballero, L.
Title Total absorption study of the beta decay of Tc-102,Tc-104,Tc-105 Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 87 Issue (up) 4 Pages 044318 - 14pp
Keywords
Abstract The beta-feeding probabilities for three important contributors to the decay heat in nuclear reactors, namely Tc-102,Tc-104,Tc-105, have been measured using the total absorption spectroscopy technique. For the measurements, sources of very high isobaric purity have been obtained using a Penning trap (JYFLTRAP). A detailed description of the data analysis is given and the results are compared with high-resolution measurements and theoretical calculations. DOI: 10.1103/PhysRevC.87.044318
Address Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: algora@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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000317395300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1402
Permanent link to this record
 
 
Author Mason, P.J.R. et al; Algora, A.
Title Half-life of the yrast 2(+) state in W-188: Evolution of deformation and collectivity in neutron-rich tungsten isotopes Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue (up) 4 Pages 044301 - 6pp
Keywords
Abstract The half-life of the yrast I-pi = 2(+) state in the neutron-rich nucleus W-188 has been measured using fast-timing techniques with the HPGe and LaBr3:Ce array at the National Institute of Physics and Nuclear Engineering, Bucharest. The resulting value of t(1/2) = 0.87(12) ns is equivalent to a reduced transition probability of B(E2;2(1)(+) -> 0(1)(+)) = 85(12) W.u. for this transition. The B(E2;2(1)(+) -> 0(1)(+)) is compared to neighboring tungsten isotopes and nuclei in the Hf, Os, and Pt isotopic chains. Woods-Saxon potential energy surface (PES) calculations have been performed for nuclei in the tungsten isotopic chain and predict prolate deformed minima with rapidly increasing gamma softness for W184-192 and an oblate minimum for W-194.
Address [Mason, P. J. R.; Podolyak, Zs.; Regan, P. H.; Stevenson, P. D.; Alexander, T.; Alharbi, T.; Bowry, M.; Britton, R.; Bunce, M.; Gelletly, W.; Rice, S.; Townsley, C.; Wilson, E.; Wood, R. T.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000325163700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1606
Permanent link to this record
 
 
Author AGATA Collaboration (Modamio, V. et al); Gadea, A.; Algora, A.; Huyuk, T.
Title Lifetime measurements in neutron-rich Co-63,Co-65 isotopes using the AGATA demonstrator Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue (up) 4 Pages 044326 - 6pp
Keywords
Abstract Lifetimes of the low-lying (11/2(-)) states in Co-63,Co-65 have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA gamma-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a U-238 target with a beam of Ni-64. The experimental B(E2) reduced transition probabilities for Co-63,Co-65 are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N = 40 Co-67 isotope.
Address [Modamio, V.; Valiente-Dobon, J. J.; Corradi, L.; de Angelis, G.; Fioretto, E.; Gottardo, A.; Montanari, D.; Napoli, D. R.; Rosso, D.; Sahin, E.; Stefanini, A. M.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy
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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000326096300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1629
Permanent link to this record