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Author IDS Collaboration (Heideman, J. et al); Algora, A.; Morales, A.I.
Title Evidence of nonstatistical neutron emission following beta decay near doubly magic Sn-132 Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 108 Issue 2 Pages 024311 - 9pp
Keywords
Abstract Models of the beta-delayed neutron emission (beta n) assume that neutrons are emitted statistically via an intermediate compound nucleus post beta decay. Evidence to the contrary was found in an In-134 beta-decay experiment carried out at ISOLDE CERN. Neutron emission probabilities from the unbound states in Sn-134 to known low-lying, single-particle states in Sn-133 were measured. The neutron energies were determined using the time-of-flight technique, and the subsequent decay of excited states in Sn-133 was studied using gamma-ray detectors. Individual beta n probabilities were determined by correlating the relative intensities and energies of neutrons and gamma rays. The experimental data disagree with the predictions of representative statistical models which are based upon the compound nucleus postulate. Our results suggest that violation of the compound nucleus assumption may occur in beta-delayed neutron emission. This impacts the neutron-emission probabilities and other properties of nuclei participating in the r-process. A model of neutron emission, which links the observed neutron emission probabilities to nuclear shell effects, is proposed.
Address [Heideman, J.; Grzywacz, R.; Xu, Z. Y.; Madurga, M.; Halverson, C.; King, T. T.; Singh, M.; Yokoyama, R.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA
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) 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001053419100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5620
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Author Xu, Z.Y. et al; Algora, A.; Morales, A.I.
Title Beta-delayed neutron spectroscopy of 133In Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 108 Issue 1 Pages 014314 - 9pp
Keywords
Abstract The decay properties of 133In were studied in detail at the ISOLDE Decay Station. The implementation of the Resonance Ionization Laser Ion Source allowed separate measurements of its 9/2+ ground state (133gIn) and 1/2- isomer (133mIn). With the use of & beta;-delayed neutron and & gamma; spectroscopy, the decay strengths above the neutron separation energy were quantified in this neutron-rich nucleus for the first time. The allowed Gamow-Teller transition 9/2+ & RARR; 7/2+ was located at 5.93 MeV in the 133gIn decay with a log ft = 4.7(1). In addition, several neutron-unbound states were populated at lower excitation energies by the first-forbidden decays of 133g,mIn. We assigned spins and parities to those neutron-unbound states based on the & beta;-decay selection rules, the log ft values, and systematics.
Address [Xu, Z. Y.; Madurga, M.; Grzywacz, R.; King, T. T.; Halverson, C.; Heideman, J.; Singh, M.; Yokoyama, R.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA
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) 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001062056700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5757
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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 β-delayed neutron emissions from N > 50 gallium isotopes Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 108 Issue 6 Pages 064307 - 15pp
Keywords
Abstract beta-delayed gamma-neutron spectroscopy has been performed on the decay of A=84 to 87 gallium isotopes at the RI-beam Factory at the RIKEN Nishina Center using a high-efficiency array of 3He neutron counters (BRIKEN). beta-2n-gamma events were measured in the decays of all of the four isotopes for the first time, which is direct evidence for populating the excited states of two-neutron daughter nuclei. Detailed decay schemes with the gamma branching ratios were obtained for these isotopes, and the neutron emission probabilities (P-xn) were updated from the previous study. Hauser-Feshbach statistical model calculations were performed to understand the experimental branching ratios. We found that the P-1n and P-2n values are sensitive to the nuclear level densities of 1n daughter nuclei and showed that the statistical model reproduced the P-2n/P-1n ratio better when experimental levels plus shell-model level densities fit by the Gilbert-Cameron formula were used as the level-density input. We also showed the neutron and gamma branching ratios are sensitive to the ground-state spin of the parent nucleus. Our statistical model analysis suggested J <= 3 for the unknown ground-state spin of the odd-odd nucleus Ga-86, from the I gamma(4(+)-> 2(+))/I-gamma(2(+)-> 0(+)) ratio of Ga-84 and the P-2n/P-1n ratio. These results show the necessity of detailed understanding of the decay scheme, including data from neutron spectroscopy, in addition to gamma measurements of the multineutron emitters.
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: yokoyama@cns.s.u-tokyo.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 (down) 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:001159167500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5939
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Author HISPEC-DESPEC Collaboration (Polettini, M. et al); Algora, A.; Morales, A.I.; Orrigo, S.E.A.
Title Decay studies in the A similar to 225 Po-Fr region from the DESPEC campaign at GSI in 2021 Type Journal Article
Year 2022 Publication Nuovo Cimento C Abbreviated Journal Nuovo Cim. C
Volume 45 Issue 5 Pages 125 - 4pp
Keywords
Abstract The HISPEC-DESPEC collaboration aims at investigating the struc-ture of exotic nuclei formed in fragmentation reactions with decay spectroscopymeasurements, as part of the FAIR Phase-0 campaign at GSI. This paper reportson first results of an experiment performed in spring 2021, with a focus on beta-decaystudies in the Po-Fr nuclei in the 220 < A <230 island of octupole deformationexploiting the DESPEC setup. Ion-beta correlations and fast-timing techniques arebeing employed, giving an insight into this difficult-to-reach region.
Address [Polettini, M.; Benzoni, G.; Genna, D.; Bracco, A.; Bottoni, S.; Camera, F.; Crespi, F. C. L.; Gamba, E. R.; Leoni, S.; Million, B.; Porzio, C.; Wieland, O.; Ziliani, S.] Univ Milan, Dipartimento Fis, Milan, Italy
Corporate Author Thesis
Publisher Soc Italiana Fisica Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 2037-4909 ISBN Medium
Area Expedition Conference
Notes WOS:000819174100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5292
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Author BRIKEN Collaboration (Tarifeño-Saldivia, A. et al); Tain, J.L.; Domingo-Pardo, C.; Agramunt, J.; Algora, A.; Morales, A.I.; Rubio, B.; Tolosa, A.
Title Conceptual design of a hybrid neutron-gamma detector for study of beta-delayed neutrons at the RIB facility of RIKEN Type Journal Article
Year 2017 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 12 Issue Pages P04006 - 22pp
Keywords Detector modelling and simulations I (interaction of radiation with matter, interaction; of photons with matter, interaction of hadrons with matter, etc); Instrumentation for radioactive beams (fragmentation devices; fragment and isotope, separators incl. ISOL; isobar separators; ion and atom traps; weak-beam diagnostics; radioactive-beam ion sources); Neutron detectors (cold, thermal, fast neutrons)
Abstract BRIKEN is a complex detection system to be installed at the RIB-facility of the RIKEN Nishina Center. It is aimed at the detection of heavy-ion implants, β-particles, γ-rays and β-delayed neutrons. The whole detection setup involves the Advanced Implantation Detection Array (AIDA), two HPGe Clover detectors and a large set of 166 counters of 3He embedded in a high-density polyethylene matrix. This article reports on a novel methodology developed for the conceptual design and optimisation of the 3He-tubes array, aiming at the best possible performance in terms of neutron detection. The algorithm is based on a geometric representation of two selected parameters of merit, namely, average neutron detection efficiency and efficiency flatness, as a function of a reduced number of geometric variables. The response of the detection system itself, for each configuration, is obtained from a systematic MC-simulation implemented realistically in Geant4. This approach has been found to be particularly useful. On the one hand, due to the different types and large number of 3He-tubes involved and, on the other hand, due to the additional constraints introduced by the ancillary detectors for charged particles and gamma-rays. Empowered by the robustness of the algorithm, we have been able to design a versatile detection system, which can be easily re-arranged into a compact mode in order to maximize the neutron detection performance, at the cost of the gamma-ray sensitivity. In summary, we have designed a system which shows, for neutron energies up to 1(5) MeV, a rather flat and high average efficiency of 68.6%(64%) and 75.7%(71%) for the hybrid and compact modes, respectively. The performance of the BRIKEN system has been also quantified realistically by means of MC-simulations made with different neutron energy distributions.
Address [Tarifeno-Saldivia, A.] UPC, Barcelona, Spain, Email: ariel.esteban.tarifeno@upc.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000405067800006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3209
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Author IDS Collaboration (Lica, R. et al); Morales, A.I.
Title beta decay studies of n-rich Cs isotopes with the ISOLDE Decay Station Type Journal Article
Year 2017 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume 44 Issue 5 Pages 054002 - 14pp
Keywords beta decay; exotic nuclei; nuclear deformation; ISOLDE
Abstract Neutron-rich Ba isotopes are expected to exhibit octupolar correlations, reaching their maximum in isotopes around mass A = 146. The odd-A neutron-rich members of this isotopic chain show typical patterns related to non-axially symmetric shapes, which are however less marked compared to even-A ones, pointing to a major contribution from vibrations. In the present paper we present results from a recent study focused on Cs148-150 beta-decay performed at the ISOLDE Decay Station equipped with fast-timing detectors. A detailed analysis of the measured decay half-lives and decay scheme of Ba-149 is presented, giving a first insight in the structure of this neutron-rich nucleus.
Address [Lica, R.; Borge, M. J. G.; Madurga, M.; Kurcewicz, J.] CERN, CH-1211 Geneva 23, Switzerland, Email: giovanna.benzoni@mi.infn.it
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000398756400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3053
Permanent link to this record
 

 
Author Morales, A.I.; Tuzon, P.
Title Misconceptions, Knowledge, and Attitudes Towards the Phenomenon of Radioactivity Type Journal Article
Year 2022 Publication Science & Education Abbreviated Journal Sci. Educ.
Volume 31 Issue Pages 405-426
Keywords
Abstract The teaching of the phenomenon of radioactivity is considered a key ingredient in the path towards developing critical thinking skills in many secondary science education curricula. Despite being one of the basic concepts in general physics courses, the scientific teaching literature of the last 40 years reports a great deal of misconceptions and conceptual errors related to radioactivity that seemingly appear regardless of the educational level and context. This study reports the first cross-sectional diagnostic study in Spain to secondary education students and pre-service teachers. Data were collected in the year 2019 through a questionnaire adapted from a previously validated one to explore the main misconceptions, attitudes, and knowledge status on the topic on a sample of 191 secondary school students and 29 Physics-and-Chemistry trainee teachers in the Spanish region of Valencia. Open and closed questions were used to categorize the entity itself, its properties, and the main misconceptions related to radioactivity. The responses were analysed using conventional statistical methods. The results indicate an evolution from a widespread dissenting notion on the phenomenon, which is staunchly related to danger, hazard, and destruction in the lowest educational levels, towards a more rational, relative, and multidimensional perspective in the highest ones. On the other hand, the ideas, emotions, and attitudes of the inquired individuals are in good agreement with the main misconceptions reported in the literature.
Address [Morales Lopez, Ana Isabel] Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: aimolo@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 (down) 0926-7220 ISBN Medium
Area Expedition Conference
Notes WOS:000679599100001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4903
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Author Morales, A.I. et al; Agramunt, J.; Algora, A.; Gadea, A.; Molina, F.; Rubio, B.
Title Synthesis of N=127 isotones through (p,n) charge-exchange reactions induced by relativistic (208)Pb projectiles Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 84 Issue 1 Pages 011601 - 5pp
Keywords
Abstract The production cross sections of four N = 127 isotones ((207)Hg, (206)Au, (205)Pt, and (204)Ir) have been measured using (p,n) charge-exchange reactions, induced in collisions of a (208)Pb primary beam at 1 A GeV with a Be target. These data allow one to investigate the use of a reaction mechanism to extend the limits of the chart of nuclides toward the important r-process nuclei in the region of the third peak of elemental abundance distribution.
Address [Morales, AI; Benlliure, J; Alvarez-Pol, H; Casarejos, E; Dragosavac, D; Perez-Loureiro, D; Verma, S] Univ Santiago de Compostela, Santiago De Compostela 15782, Spain, Email: anaisabel.morales@usc.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) 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000292925800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 697
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Author Morales, A.I. et al; Algora, A.; Molina, F.; Rubio, B.
Title beta-delayed gamma-ray spectroscopy of Au-203,Au-204 and Pt200-202 Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue 1 Pages 014319 - 12pp
Keywords
Abstract The beta decay of five heavy, neutron-rich nuclei, Pt-203,Pt-204 and Ir200-202, has been investigated following relativistic cold fragmentation reactions of lead projectiles using the FRS + RISING setup at GSI. This paper reports on the study of the low-lying states in the decay daughter nuclei Au-203,Au-204 and Pt200-202. The characteristic gamma rays for each nucleus have been determined using beta-delayed gamma-ray spectroscopy. Tentative level schemes, relative intensities, and apparent beta feedings are provided. These data are compared with shell-model calculations, which indicate a substantial contribution to the total beta strength from high-energy first-forbidden beta-decay transitions in this mass region.
Address [Morales, A. I.; Benlliure, J.; Verma, S.; Casarejos, E.; Alvarez-Pol, H.; Estevez-Aguado, M. E.] Univ Santiago de Compostela, E-15782 Santiago De Compostela, Spain, Email: anaisabel.morales@mi.infn.it
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) 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000322113600003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1527
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Author Morales, A.I. et al; Gadea, A.; Algora, A.
Title beta-decay studies of neutron-rich Tl, Pb, and Bi isotopes Type Journal Article
Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 89 Issue 1 Pages 014324 - 13pp
Keywords
Abstract The fragmentation of relativistic uranium projectiles has been exploited at the Gesellschaft fur Schwerionenforschung laboratory to investigate the beta decay of neutron-rich nuclei just beyond Pb-208. This paper reports on beta-delayed gamma decays of Tl211-213, Pb-215, and Bi215-219 de-exciting states in the daughters Pb211-213, Bi-215, and Po215-219. The resulting partial level schemes, proposed with the help of systematics and shell-model calculations, are presented. The role of allowed Gamow-Teller and first-forbidden beta transitions in this mass region is discussed.
Address [Morales, A. I.; Benzoni, G.; Blasi, N.; Bracco, A.; Camera, F.; Crespi, F. C. L.; Corsi, A.; Leoni, S.; Million, B.; Nicolini, R.; Wieland, O.] Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy, Email: anaisabel.morales@mi.infn.it
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) 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000332158900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1720
Permanent link to this record