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Author Watanabe, H. et al; Montaner-Piza, A.
Title New isomers in (125)Pd(79)( )and Pd-127(81): Competing proton and neutron excitations in neutron-rich palladium nuclides towards the N=82 shell closure Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 792 Issue Pages 263-268
Keywords
Abstract The neutron-rich isotopes of palladium have attracted considerable interest in terms of the evolution of the N = 82 neutron shell closure and its influence on the r-process nucleosynthesis. In this Letter, we present the first spectroscopic information on the excited states in Pd-125(79) and Pd-127(81) studied using the EURICA gamma-ray spectrometer, following production via in-flight fission of a high-intensity U-238 beam at the RIBF facility. New isomeric states with half-lives of 144(4) ns and 39(6) μs have been assigned spins and parities of (23/2(+)) and (19/2(+)) in Pd-125 and Pd-127, respectively. The observed level properties are compared to a shell-model calculation, suggesting the competition between proton excitations and neutron excitations in the proton-hole and neutron-hole systems in the vicinity of the doubly magic nucleus Sn-132.
Address [Watanabe, H.] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: hiroshi@ribf.riken.jp
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000466802100040 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3998
Permanent link to this record
 
 
Author Watanabe, H. et al; Montaner-Piza, A.
Title Impact of shell evolution on Gamow-Teller beta decay from a high-spin long-lived isomer in Ag-127 Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 823 Issue Pages 136766 - 6pp
Keywords Shell evolution; Gamow-Teller beta decay; Isomer; Ag-127; Radioactive isotope beam
Abstract The change of the shell structure in atomic nuclei, so-called “nuclear shell evolution”, occurs due to changes of major configurations through particle-hole excitations inside one nucleus, as well as due to variation of the number of constituent protons or neutrons. We have investigated how the shell evolution affects Gamow-Teller (GT) transitions that dominate the beta decay in the region below Sn-132 using the newly obtained experimental data on a long-lived isomer in Ag-127. The T-1/2 = 67.5(9) ms isomer has been identified with a spin and parity of (27/2(+)) at an excitation energy of 1942(-20)(+14) keV, and found to decay via an internal transition of an E3 character, which competes with the dominant beta-decay branches towards the high-spin states in Cd-127. The underlying mechanism of a strong GT transition from the Ag-127 isomer is discussed in terms of configuration-dependent optimization of the effective single-particle energies in the framework of a shell-model approach.
Address [Watanabe, H.] Beihang Univ, Sch Phys, Beijing 100191, Peoples R China, Email: hiroshi@ribf.riken.jp
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 (down) 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000719296400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5041
Permanent link to this record
 
 
Author Vitez-Sveiczer, A. et al; Algora, A.; Morales, A.I.; Rubio, B.; Agramunt, J.; Guadilla, V.; Montaner-Piza, A.; Orrigo, S.E.A.
Title The beta-decay of Kr-70 into Br-70: Restoration of the pseudo-SU(4) symmetry Type Journal Article
Year 2022 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 830 Issue Pages 137123 - 8pp
Keywords Beta decay of Kr-70; pn pairing; GT strength distribution; Pseudo-SU(4) symmetry; QRPA calculations
Abstract The beta-decay of the even-even nucleus Kr-70 with Z=N+2, has been investigated at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center using the BigRIPS fragment separator, the ZeroDegree Spectrometer, the WAS3ABI implantation station and the EURICA HPGe cluster array. Fifteen gamma-rays associated with the beta-decay of( 70)Kr into Br-70 have been identified for the first time, defining ten populated states below E-exc=3300 keV. The half-life of Kr-70 was derived with increased precision and found to be t(1/2)=45.19 +/- 0.14 ms. The beta-delayed proton emission probability has also been determined as epsilon(p)=0.545(23)%. An increase in the beta-strength to the yrast 1(+) state in comparison with the heaviest Z=N+2 system studied so far (Ge-62 decay) is observed that may indicate increased np correlations in the T=0 channel. The beta-decay strength deduced from the results is interpreted in terms of the proton-neutron quasiparticle random-phase approximation (pnQRPA) and also with a schematic model that includes isoscalar and isovector pairing in addition to quadrupole deformation. The application of this last model indicates an approximate realization of pseudo-SU(4) symmetry in this system.
Address [Vitez-Sveiczer, A.; Algora, A.; Morales, A., I; Rubio, B.; Agramunt, J.; Guadilla, V; Montaner-Piza, A.; Orrigo, S. E. A.; Gelletly, W.] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: algora@ific.uv.es;
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 (down) 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000832707200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5316
Permanent link to this record
 
 
Author Tain, J.L.; Algora, A.; Agramunt, J.; Guadilla, V.; Jordan, M.D.; Montaner-Piza, A.; Rubio, B.; Valencia, E.; Cano-Ott, D.; Gelletly, W.; Martinez, T.; Mendoza, E.; Podolyak, Z.; Regan, P.; Simpson, J.; Smith, A.J.; Strachan, J.
Title A decay total absorption spectrometer for DESPEC at FAIR Type Journal Article
Year 2015 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 803 Issue Pages 36-46
Keywords Total absorption gamma-ray spectrometer; Scintillation detectors; Beta decay; High-energy beam fragmentation facilities
Abstract This paper presents the design of a total absorption gamma-ray spectrometer for the determination of beta-decay intensity distributions of exotic nuclear species at the focal plane of the FAIR-NUSTAR Super Fragment Separator. The spectrometer is a key instrument in the DESPEC experiment and the proposed implementation follows extensive design studies and prototype tests. Two options were contemplated, based on Nal(TI) and LaBr3:Ce inorganic scintillation crystals respectively. Monte Carlo simulations and technical considerations determined the optimal configurations consisting of sixteen 15 x 15 x 25 cm(3) crystals for the Nal(Tl) option and one hundred and twenty-eight 5.5 x 5.5 x 11 cm(3) crystals for the LaBr3:Ce option. Minimization of dead material was crucial for maximizing the spectrometer full-energy peak efficiency. Module prototypes were build to verify constructional details and characterize their performance. The measured energy and timing resolution was found to agree rather well with estimates based on simulations of scintillation light transport and collection. The neutron sensitivity of the spectrometer, important when measuring beta-delayed neutron emitters, was investigated by means of Monte Carlo simulations.
Address [Tain, J. L.; Algora, A.; Agramunt, J.; Guadilla, V.; Jordan, M. D.; Montaner-Piza, A.; Rubio, B.; Valencia, E.] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: tain@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000363464600007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2431
Permanent link to this record
 
 
Author Guadilla, V. et al; Algora, A.; Tain, J.L.; Agramunt, J.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S.E.A.; Rubio, B.; Valencia, E.
Title Characterization of a cylindrical plastic beta-detector with Monte Carlo simulations of optical photons Type Journal Article
Year 2017 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 854 Issue Pages 134-138
Keywords Plastic scintillators; Monte Carlo simulations; Total absorption spectroscopy; Optical photons
Abstract In this work we report on the Monte Carlo study performed to understand and reproduce experimental measurements of a new plastic beta-detector with cylindrical geometry. Since energy deposition simulations differ from the experimental measurements for such a geometry, we show how the simulation of production and transport of optical photons does allow one to obtain the shapes of the experimental spectra. Moreover, taking into account the computational effort associated with this kind of simulation, we develop a method to convert the simulations of energy deposited into light collected, depending only on the interaction point in the detector. This method represents a useful solution when extensive simulations have to be done, as in the case of the calculation of the response function of the spectrometer in a total absorption gamma-ray spectroscopy analysis.
Address [Guadilla, V.; Algora, A.; Tain, J. L.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S. E. A.; Rubio, B.; Valencia, E.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: victor.guadilla@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000398869100018 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3052
Permanent link to this record
 
 
Author Guadilla, V. et al; Tain, J.L.; Algora, A.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S.E.A.; Rubio, B.; Valencia, E.
Title Characterization and performance of the DTAS detector Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 910 Issue Pages 79-89
Keywords beta decay; Total absorption gamma-ray spectrometer; Exotic nuclei; NaI(Tl) detector; Non-proportional scintillation light yield; Monte Carlo simulations
Abstract DTAS is a segmented total absorption y-ray spectrometer developed for the DESPEC experiment at FAIR. It is composed of up to eighteen NaI(Tl) crystals. In this work we study the performance of this detector with laboratory sources and also under real experimental conditions. We present a procedure to reconstruct offline the sum of the energy deposited in all the crystals of the spectrometer, which is complicated by the effect of NaI(Tl) light-yield non-proportionality. The use of a system to correct for time variations of the gain in individual detector modules, based on a light pulse generator, is demonstrated. We describe also an event-based method to evaluate the summing-pileup electronic distortion in segmented spectrometers. All of this allows a careful characterization of the detector with Monte Carlo simulations that is needed to calculate the response function for the analysis of total absorption gamma-ray spectroscopy data. Special attention was paid to the interaction of neutrons with the spectrometer, since they are a source of contamination in studies of beta-delayed neutron emitting nuclei.
Address [Guadilla, V; Tain, J. L.; Algora, A.; Agramunt, J.; Gelletly, W.; Jordan, D.; Monserrate, M.; Montaner-Piza, A.; Orrigo, S. E. A.; Rubio, B.; Valencia, E.] CSIC Univ Valencia, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: guadilla@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000453652500010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3847
Permanent link to this record
 
 
Author Algora, A. et al; Valencia, E.; Tain, J.L.; Jordan, M.D.; Agramunt, J.; Rubio, B.; Estevez, E.; Molina, F.; Montaner-Piza, A.; Guadilla, V.
Title Total Absorption Study of Beta Decays Relevant for Nuclear Applications and Nuclear Structure Type Journal Article
Year 2014 Publication Nuclear Data Sheets Abbreviated Journal Nucl. Data Sheets
Volume 120 Issue Pages 12-15
Keywords
Abstract An overview is given of our activities related to the study of the beta decay of neutron rich nuclei relevant for nuclear applications. Recent results of the study of the beta decay of Br-87,Br-88 using a new segmented total absorption spectrometer are presented. The measurements were performed at the IGISOL facility using trap-assisted total absorption spectroscopy.
Address [Algora, A.; Valencia, E.; Tain, J. L.; Jordan, M. D.; Agramunt, J.; Rubio, B.; Estevez, E.; Molina, F.; Montaner, A.; Guadilla, V.] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: algora@ific.uv.es
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 (down) 0090-3752 ISBN Medium
Area Expedition Conference
Notes WOS:000339860100004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1869
Permanent link to this record
 
 
Author Rubio, B. et al; Orrigo, S.E.A.; Montaner-Piza, A.; Agramunt, J.; Algora, A.; Molina, F.
Title Beta Decay Study of the T-z =-2 Zn-56 Nucleus and the Determination of the Half-Lives of a Few fp-shell Nuclei Type Journal Article
Year 2014 Publication Nuclear Data Sheets Abbreviated Journal Nucl. Data Sheets
Volume 120 Issue Pages 37-40
Keywords
Abstract This paper concerns the experimental study of the beta decay properties of few proton-rich fp-shell nuclei. The nuclei were produced at GANIL in fragmentation reactions, separated with the LISE spectrometer and stopped in an implantation detector surrounded by Ge detectors. The beta-delayed gammas, beta-delayed protons and the exotic beta-delayed gamma-proton emission have been studied. Preliminary results are presented. The decay of the T-z = -2 nucleus Zn-56 has been studied in detail. Information from the beta-delayed protons and beta-delayed gammas has been used to deduce the decay scheme. The exotic beta-delayed gamma-proton decay has been observed for the first time in the fp-shell. The interpretation of the data was made possible thanks to the detailed knowledge of the mirror Charge Exchange (CE) process and the gamma de-excitation of the states in Co-56, the mirror nucleus of Cu-56.
Address [Rubio, B.; Orrigo, S. E. A.; Montaner-Piza, A.; Agramunt, J.; Algora, A.; Molina, F.] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: Berta.Rubio@ific.uv.es
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 (down) 0090-3752 ISBN Medium
Area Expedition Conference
Notes WOS:000339860100010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1870
Permanent link to this record
 
 
Author Watanabe, H. et al; Montaner-Piza, A.
Title Isomers in Pd-128 and Pd-126: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes Type Journal Article
Year 2013 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 111 Issue 15 Pages 152501 - 5pp
Keywords
Abstract The level structures of the very neutron-rich nuclei Pd-128 and Pd-126 have been investigated for the first time. In the r-process waiting-point nucleus Pd-128, a new isomer with a half-life of 5.8(8) μs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority v = 2. For Pd-126, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) μs. The yrast 2(+) energy is much higher in Pd-128 than in Pd-126, while the level sequence below the 8(+) isomer in Pd-128 is similar to that in the N = 82 isotone Cd-130. The electric quadrupole transition that depopulates the 8(+) isomer in Pd-128 is more hindered than the corresponding transition in Cd-130, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N = 82 is fairly robust in the neutron-rich Pd isotopes.
Address [Watanabe, H.] Beihang Univ, Int Res Ctr Nuclei & Particles Cosmos, Beijing 100191, Peoples R China, Email: hiroshi@ribf.riken.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 (down) 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000325372500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1605
Permanent link to this record
 
 
Author Taprogge, J. et al; Gadea, A.; Montaner-Piza, A.
Title 1p(3/2) Proton-Hole State in Sn-132 and the Shell Structure Along N=82 Type Journal Article
Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 112 Issue 13 Pages 132501 - 6pp
Keywords
Abstract A low-lying state in In-131(82), the one-proton hole nucleus with respect to double magic Sn-132, was observed by its gamma decay to the I-pi 1/2(-) beta-emitting isomer. We identify the new state at an excitation energy of E-x = 1353 keV, which was populated both in the beta decay of Cd-131(83) and after beta-delayed neutron emission from Cd-132(84), as the previously unknown pi p(3/2) single-hole state with respect to the Sn-132 core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible N = 82 isotones below Sn-132. The results evidence a surprising absence of proton subshell closures along the chain of N = 82 isotones. The consequences of this finding for the evolution of the N = 82 shell gap along the r-process path are discussed.
Address [Taprogge, J.; Jungclaus, A.] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: andrea.jungclaus@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 (down) 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000334336600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1759
Permanent link to this record