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1. Getting in Front of Chronic Wasting Disease: Model-Informed Proactive Approach for Managing an Emerging Wildlife Disease

Author

Aniruddha V. Belsare, Joshua J. Millspaugh, J. R. Mason, Jason Sumners, Hildegunn Viljugrein, and Atle Mysterud

Subjects
agent-based models, chronic wasting disease, pre-emptive strategies, surveillance, white-tailed deer, Veterinary medicine, SF600-1100
Abstract

Continuing geographic spread of chronic wasting disease (CWD) poses a serious threat to the sustainable future of cervids and hunting in North America. Moreover, CWD has been detected in captive cervids in South Korea and, in recent years, in free-ranging reindeer in Europe (Norway). Management of this disease is limited by logistical, financial, and sociopolitical considerations, and current strategies primarily focus on reducing host densities through hunter harvest and targeted culling. The success of such strategies in mitigating the spread and prevalence of CWD only upon detection is questionable. Here, we propose a proactive approach that emphasizes pre-emptive management through purposeful integration of virtual experiments (simulating alternate interventions as model scenarios) with the aim of evaluating their effectiveness. Here, we have used a published agent-based model that links white-tailed deer demography and behavior with CWD transmission dynamics to first derive a CWD outbreak trajectory and then use the trajectory to highlight issues associated with different phases of the CWD outbreak (pre-establishment/transition/endemic). Specifically, we highlight the practical constraints on surveillance in the pre-establishment phase and recommend that agencies use a realistic detection threshold for their CWD surveillance programs. We further demonstrate that many disease introductions are “dead ends” not leading to a full epidemic due to high stochasticity and harvesting in the pre-establishment phase of CWD. Model evaluated pre-emptive (pre-detection) harvest strategies could increase the resilience of the deer population to CWD spread and establishment. We conclude it is important to adaptively position CWD management ahead of, rather than behind, the CWD front.

Published
2021
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2. Nanosecond lifetime measurements of Iπ=9/2- intrinsic excited states and low-lying B(E1) strengths in 183Re using combined HPGe-LaBr3 coincidence spectroscopy

Author

R. Britton, D. Ghita, D. Deleanu, T. Sava, R. T. Wood, A. Olacel, Alison Bruce, Ioana Gheorghe, I. Cǎta-Danil, V. Werner, T. Glodariu, N. Florea, R. Mǎrginean, K.F. Mulholland, N. Alkhomashi, L. Stroe, P. J. R. Mason, Raymond J. Carroll, D. Bucurescu, Zs. Podolyák, T. Alharbi, P. A. Söderström, T. Daniel, C. Mihai, N. Mǎrginean, P. H. Regan, L. A. Gurgi, R. Lice, S. Toma, A. Negret, Oliver J. Roberts, A.D. Bajoga, R. Suvaila, and E. Wilson

Subjects
Physics, Radiation, 010308 nuclear & particles physics, Gamma ray, 01 natural sciences, Electromagnetic radiation, Semiconductor detector, Nuclear physics, Excited state, 0103 physical sciences, Gamma spectroscopy, Atomic physics, Electric dipole transition, Nuclear Experiment, 010306 general physics, Spectroscopy, Excitation
Abstract

This paper presents precision measurements of electromagnetic decay probabilities associated with electric dipole transitions in the prolate-deformed nucleus 183Re. The nucleus of interest was formed using the fusion evaporation reaction 180Hf(7Li,4n)183Re at a beam energy of 30 MeV at the tandem accelerator at the HH-IFIN Institute, Bucharest Romania. Coincident decay gamma rays from near-yrast cascades were detected using the combined HPGe-LaBr3 detector array ROSPHERE. The time differences between cascade gamma rays were measured using the LaBr3 detectors to determine the half-lives of the two lowest lying spin-parity 9/2- states at excitation energies of 496 and 617 keV to be 5.65(5) and 2.08(3) ns respectively. The deduced E1 transition rates from these two states are discussed in terms of the K-hindrance between the low-lying structures in this prolate-deformed nucleus.

Published
2017

3. Fine structure in the α decay of Lu156 and Ta158

Author

Rauno Julin, Jan Sarén, Joonas Konki, Catherine Scholey, M. Labiche, Paul Greenlees, P. J. R. Mason, J. Simpson, Philippos Papadakis, Kalle Auranen, Mikael Sandzelius, A. Thornthwaite, Sanna Stolze, Andrej Herzan, C. McPeake, Panu Rahkila, Juha Sorri, Panu Ruotsalainen, Pauli Peura, E. Parr, L. Capponi, Jack Henderson, Sakari Juutinen, M. Smolen, Jari Partanen, J. P. Revill, Janne Pakarinen, Tuomas Grahn, J. F. Smith, Juha Uusitalo, F. A. Ali, Matti Leino, David O'Donnell, Robert Page, Ulrika Jakobsson, and D. T. Joss

Subjects
Physics, Condensed matter physics, Structure (category theory)
Published
2019

4. Fine structure in the α decay of high-spin isomers in Lu155 and Hf156

Author

Rauno Julin, F. A. Ali, Sanna Stolze, Panu Rahkila, Catherine Scholey, M. Labiche, Philippos Papadakis, Robert Page, A. Thornthwaite, C. McPeake, Jan Sarén, Panu Ruotsalainen, J. P. Revill, Pauli Peura, Tuomas Grahn, David O'Donnell, L. Capponi, Kalle Auranen, Juha Uusitalo, P. J. R. Mason, Joonas Konki, Ulrika Jakobsson, J. F. Smith, Juha Sorri, M. Smolen, Jayne Simpson, Paul Greenlees, Mikael Sandzelius, E. Parr, Matti Leino, Jari Partanen, Janne Pakarinen, Jack Henderson, Andrej Herzan, Sakari Juutinen, and D. T. Joss

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Alpha (ethology), Alpha decay, Atomic physics, 010306 general physics, 01 natural sciences, Coincidence, Spin-½
Abstract

Fine structure in the a decay of high-spin isomers in Lu-155( 25/2(-)) and Hf-156(8(+))has been studied for the first time using alpha gamma- coincidence analysis. Three new a decays from Lu-155(25 ...

Published
2018

5. Decay of a 19− isomeric state in Lu156

Author

Ulrika Jakobsson, M. Smolen, Philippos Papadakis, Jan Sarén, Juha Sorri, L. Capponi, B. Saygi, M. Leino, Jack Henderson, J. F. Smith, Sakari Juutinen, A. Thornthwaite, Markus Nyman, Panu Rahkila, Pauli Peura, Paul Greenlees, J. P. Revill, M. C. Lewis, Jari Partanen, Janne Pakarinen, Catherine Scholey, M. Labiche, Tuomas Grahn, F. A. Ali, A. D. Briscoe, Robert Page, Panu Ruotsalainen, Juha Uusitalo, J. Simpson, Andrej Herzan, Sanna Stolze, David O'Donnell, Rauno Julin, C. McPeake, D. T. Joss, Joonas Konki, Kalle Auranen, Mikael Sandzelius, P. J. R. Mason, and E. Parr

Subjects
Nuclear physics, Physics, 010308 nuclear & particles physics, Yrast, 0103 physical sciences, State (functional analysis), 010306 general physics, 01 natural sciences
Abstract

A multiparticle spin-trap isomeric state having a half-life of 179(4) ns and lying 2601 keV above the yrast 10(+) state in Lu-156 has been discovered. The Lu-156 nuclei were produced by bombarding ...

Published
2018

6. Total absorption spectroscopy study of the β decay of Br86 and Rb91

Author

P. J. R. Mason, M. Reponen, D. Cano-Ou, E. Mendoza, Jani Hakala, Tommi Eronen, V. Gorlychev, Juho Rissanen, Berta Rubio, L. Batist, E. Valencia, B. Gomez-Hornillos, W. Gelletly, Ari Jokinen, Volker Sonnenschein, V.-V. Elomaa, T. Martinez, R. Caballero-Folch, Pedro Sarriguren, Amanda Porta, Iain Moore, Muriel Fallot, F. G. Kondev, E. Estevez, Veli Kolhinen, M. Bowry, A.-A. Zakari-Issoufou, G. F. Farrelly, Zs. Podolyák, A. A. Sonzogni, M. D. Jordan, Heikki Penttilä, Alejandro Algora, Jorge Agramunt, J. L. Tain, Juha Äystö, P. H. Regan, Stephen Rice, V. M. Bui, and A. R. García

Subjects
Physics, Fission products, Decay scheme, Total absorption spectroscopy, 010308 nuclear & particles physics, Pandemonium effect, 01 natural sciences, Beta decay, Ionizing radiation, Nuclear physics, 0103 physical sciences, Beta particle, Decay heat, Nuclear Experiment, 010306 general physics
Abstract

The beta decays of 86Br and 91Rb have been studied using the total absorption spectroscopy technique. The radioactive nuclei were produced at the IGISOL facility in Jyvaskyla and further purified using the JYFLTRAP. 86Br and 91Rb are considered high priority contributors to the decay heat in reactors. In addition 91Rb was used as a normalization point in direct measurements of mean gamma energies released in the beta decay of fission products by Rudstam et al. assuming that this decay was well known from high-resolution measurements. Our results shows that both decays were suffering from the Pandemonium effect and that the results of Rudstam et al. should be renormalized.

Published
2017

7. r Process (n, \(\gamma \)) Rate Constraints from the \(\gamma \) Emission of Neutron Unbound States in \(\beta \)-Decay

Author

Stephen Rice, Juho Rissanen, J. N. Wilson, Volker Sonnenschein, Viki-Veikko Elomaa, Muriel Fallot, A. Algora, Jani Hakala, E. Valencia, R. Caballero-Folch, P. J. R. Mason, Iain Moore, Anu Kankainen, S. E. A. Orrigo, F. G. Kondev, Veli Kolhinen, Juha Äystö, A. R. García, D. Cano-Ott, Mikael Reponen, L. Batist, Ari Jokinen, E. Ganioglu, J. L. Tain, M. Lebois, B. Gomez-Hornillos, L. Le Meur, Ilkka Pohjalainen, M. Estienne, M. D. Jordan, M. Monserrate, A. A. Sonzogni, A. Cucoanes, Tommi Eronen, Heikki Penttilä, Jukka Koponen, Enrique Nácher, E. Mendoza, E. Estevez, José Antonio Briz, Amanda Porta, V. Gorlychev, T. Martinez, Jorge Agramunt, Dmitry Gorelov, K. Rytkönen, Juuso Reinikainen, T. Shiba, P. H. Regan, M. Bowry, V. Vedia, B. Rubio, G. F. Farrelly, A.-A. Zakari-Issoufou, Zs. Podolyák, Sami Rinta-Antila, W. Gelletly, Annika Voss, L. M. Fraile, V. Guadilla, V. M. Bui, A. Montaner-Pizá, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, 0103 physical sciences, r-process, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Atomic physics, Nuclear Experiment, 010306 general physics, 01 natural sciences
Abstract

International audience; Total absorption gamma-ray spectroscopy is used to measure accurately the intensity of γ emission from neutron-unbound states populated in the β-decay of delayed-neutron emitters. From the comparison of this intensity with the intensity of neutron emission a constraint on the (n, γ) cross section for highly unstable neutron-rich nuclei can be deduced. A surprisingly large γ branching was observed for a number of isotopes which might indicate the need to increase by a large factor the Hauser-Feshbach (n, γ) cross-section estimates that impact on r process abundance calculations.

Published
2017

8. Total absorption γ -ray spectroscopy of the β -delayed neutron emitters Br87 , Br88 , and Rb94

Author

Stephen Rice, Viki-Veikko Elomaa, L. Batist, A. Porta, B. Gomez-Hornillos, T. Martinez, V. Gorlichev, P. H. Regan, D. Cano-Ott, E. Valencia, V. M. Bui, J. L. Tain, M. Fallot, E. Mendoza, Juha Äystö, P. J. R. Mason, M. Bowry, A. A. Sonzogni, A.-A. Zakari-Issoufou, Mikael Reponen, F. G. Kondev, Volker Sonnenschein, B. Rubio, W. Gelletly, M. D. Jordan, Juho Rissanen, Ari Jokinen, Heikki Penttilä, Iain Moore, Zsolt Podolyak, G. F. Farrelly, Alejandro Algora, E. Estevez, Veli Kolhinen, Tommi Eronen, Jani Hakala, A. R. García, R. Caballero-Folch, and J. Agramunt

Subjects
Physics, Fission products, 010308 nuclear & particles physics, Fission, 7. Clean energy, 01 natural sciences, Spectral line, 13. Climate action, Isotopes of bromine, 0103 physical sciences, r-process, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Delayed neutron
Abstract

We investigate the decay of 87,88Br and 94Rb using total absorption γ -ray spectroscopy. These important fission products are β-delayed neutron emitters. Our data show considerable βγ intensity, so far unobserved in high-resolution γ -ray spectroscopy, from states at high excitation energy. We also find significant differences with the β intensity that can be deduced from existing measurements of the β spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the range 1–100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for γ emission from neutron unbound states populated in the daughter nucleus. The γ branching is compared to Hauser-Feshbach calculations, which allow one to explain the large value for bromine isotopes as due to nuclear structure. However the branching for 94Rb, although much smaller, hints of the need to increase the radiative width γ by one order of magnitude. This increase in γ would lead to a similar increase in the calculated (n,γ ) cross section for this very neutron-rich nucleus with a potential impact on r process abundance calculations.

Published
2017

9. Strong γ-ray emission from neutron unbound states populated in β-decay: Impact on (n,γ) cross-section estimates

Author

T. Shiba, Juho Rissanen, M. Estienne, M. Monserrate, J. N. Wilson, M. Fallot, L. M. Fraile, W. Gelletly, A. R. García, B. Rubio, V. Vedia, Sami Rinta-Antila, A. Montaner-Pizá, Jorge Agramunt, Juha Äystö, Mikael Reponen, José Antonio Briz, K. Rytkönen, F. G. Kondev, A. Algora, Volker Sonnenschein, G. F. Farrelly, Zs. Podolyák, Jani Hakala, M. Lebois, A.-A. Zakari-Issoufou, E. Estevez, Annika Voss, Ari Jokinen, L. Le Meur, E. Valencia, Jukka Koponen, M. D. Jordan, Heikki Penttilä, Tommi Eronen, D. Cano-Ott, Enrique Nácher, E. Mendoza, Ilkka Pohjalainen, R. Caballero-Folch, T. Martinez, V. Guadilla, E. Ganioglu, Iain Moore, Anu Kankainen, P. H. Regan, Veli Kolhinen, V. Gorlychev, Dmitry Gorelov, P. J. R. Mason, V.-V. Elomaa, M. Bowry, V.M. Bui, S.E.A. Orrigo, A. A. Sonzogni, Stephen Rice, L. Batist, A. Porta, B. Gomez-Hornillos, Juuso Reinikainen, J. L. Tain, A. Cucoanes, Plompen, A., Hambsch, F.-J., Schillebeeckx, P., Mondelaers, W., Heyse, J., Kopecky, S., Siegler, P., Oberstedt, S., Universidad de Valencia, Academy of Finland, Engineering and Physical Sciences Research Council (UK), National Measurement Office (UK), European Commission, Department of Energy (US), SCOAP, and Ministerio de Economía y Competitividad (España)

Subjects
Physics, ta114, 010308 nuclear & particles physics, Branching fraction, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, QC1-999, Nuclear Theory, 7. Clean energy, 01 natural sciences, 3. Good health, 0103 physical sciences, r-process, Neutron, Atomic physics, 010306 general physics, Spectroscopy, Nucleon, Nuclear Experiment, Delayed neutron, Radioactive decay, astro nuclear physics
Abstract

J. L. Taín et al. -- 6 pags., 7 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0, Total absorption gamma-ray spectroscopy is used to measure accurately the intensity of ¿ emission from neutron-unbound states populated in the ß-decay of delayed-neutron emitters. From the comparison of this intensity with the intensity of neutron emission one can deduce information on the (n,¿) cross section for unstable neutron-rich nuclei of interest in r process abundance calculations. A surprisingly large ¿ branching was observed for a number of isotopes. The results are compared with Hauser-Feshbach calculations and discussed., This work was supported by Spanish Ministerio de Economía y Competitividad under grants FPA2008-06419, FPA2010- 17142, FPA2011-24553, FPA2014-52823-C2-1-P, CPAN CSD- 2007-00042 (Ingenio2010) and the program Severo Ochoa (SEV-2014-0398). WG would like to thank the University of Valencia for support. This work was supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2012-2017 (Project No. 21350). Work supported by EPSRC(UK) and STFC(UK) and the UK National Measurement Office. Work supported by the European Commission under the FP7/EURATOM contract 605203. FGK acknowledges support from the U.S. Department of Energy, under contract number DEAC02- 06CH11357.

Published
2017

10. Total absorption studies of high priority decays for reactor applications: 86Br and 91Rb

Author

V. Vedia, Sami Rinta-Antila, M. Estienne, E. Ganioglu, J. L. Tain, T. Shiba, M. Monserrate, M. Fallot, T. Martinez, A. R. García, W. Gelletly, L. M. Fraile, V.M. Bui, E. Valencia, Iain Moore, A. Cucoanes, J.-Ch. Sublet, M. Lebois, Anu Kankainen, E. Estevez, V. Guadilla, S.E.A. Orrigo, Veli Kolhinen, Juha Äystö, Annika Voss, A. A. Sonzogni, Juho Rissanen, Tommi Eronen, Mikael Reponen, Michael Fleming, Volker Sonnenschein, Zsolt Podolyak, R. Caballero-Folch, J. N. Wilson, José Antonio Briz, Stephen Rice, D. Cano-Ott, F. G. Kondev, M. Bowry, A. Algora, P. H. Regan, Jani Hakala, Viki-Veikko Elomaa, Jorge Agramunt, V. Gorlychev, Jukka Koponen, A. Montaner-Pizá, Enrique Nácher, E. Mendoza, Dmitry Gorelov, B. Rubio, P. J. R. Mason, L. Batist, Juuso Reinikainen, A. Porta, B. Gomez-Hornillos, Ilkka Pohjalainen, K. Rytkönen, D. Jordan, Ari Jokinen, G. F. Farrelly, Heikki Penttilä, A.-A. Zakari-Issoufou, Plompen, A., Hambsch, F.-J., Schillebeeckx, P., Mondelaers, W., Heyse, J., Kopecky, S., Siegler, P., and Oberstedt, S.

Subjects
Physics, ta114, 010308 nuclear & particles physics, QC1-999, 01 natural sciences, Beta decay, Nuclear physics, nuclear masses, Beta (plasma physics), 0103 physical sciences, structure, decay data measurements, Atomic physics, 010306 general physics, Absorption (electromagnetic radiation), Nuclear Experiment
Abstract

Preliminary results from beta decay studies of nuclei that are important for reactor applications are presented. The beta decays have been studied using the total absorption technique (TAS) and the pure beams provided by the JYFLTRAP system at the IGISOL facility of the University of Jyväskylä. peerReviewed

Published
2017

11. Excited states and reduced transition probabilities in Os168

Author

Paul Stevenson, Paul Greenlees, Pauli Peura, K. Andgren, Jan Sarén, A. Dewald, Markus Nyman, Matti Leino, J. L. Wood, Tuomas Grahn, D. M. Cullen, H. Iwasaki, P. J. Sapple, B. Saygi, Juha Uusitalo, J. Simpson, A. Petts, H. V. Watkins, Sanna Stolze, O. Möller, Kristiaan Heyde, R. D. Page, Peter M. Jones, Steffen Ketelhut, Ulrika Jakobsson, L. Bianco, D. T. Joss, David O'Donnell, Panu Rahkila, Catherine Scholey, Norbert Pietralla, Kosuke Nomura, N. M. Lumley, Juha Sorri, Rauno Julin, D. S. Judson, P. J. R. Mason, M. Akmali, Th. Pissulla, and Sakari Juutinen

Subjects
Physics, Recoil, Isotope, Spectrometer, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Gamma ray, Nuclide, Atomic physics, 010306 general physics, 01 natural sciences, Coincidence
Abstract

The level scheme of the neutron-deficient nuclide 168Os has been extended and mean lifetimes of excited states have been measured by the recoil distance Doppler-shift method using the JUROGAM \gamma-ray spectrometer in conjunction with the IKP K\"oln plunger device. The 168Os \gamma rays were measured in delayed coincidence with recoiling fusion-evaporation residues detected at the focal plane of the RITU gas-filled separator. The ratio of reduced transition probabilities B(E2;4_1^+ \rightarrow 2_1^+)/B(E2;2_1^+ \rightarrow 0_1^+) is measured to be 0.34(18), which is very unusual for collective band structures and cannot be reproduced by IBM-2 model calculations based on the SkM* energy-density functional.

Published
2016

12. Total absorption spectroscopy of fission fragments relevant for reactor antineutrino spectra

Author

T. Martinez, Muriel Fallot, E. Estevez, Iain Moore, J. N. Wilson, L. Batist, Anu Kankainen, W. Gelletly, Amanda Porta, Veli Kolhinen, A. Cucoanes, Alejandro Sonzogni, M. Bowry, Juuso Reinikainen, L. M. Fraile, F. G. Kondev, D. Cano-Ott, Jukka Koponen, V. Gorlychev, Pasi Karvonen, Michael Fleming, F. Molina, Enrique Nácher, E. Mendoza, J. A. Briz, A. Perez, A. Montaner-Pizá, Tommi Eronen, Dmitry Gorelov, Juha Äystö, Ari Jokinen, Mikael Reponen, Juho Rissanen, V. Guadilla, Annika Voss, B. Rubio, L. Le Meur, M. B. Gómez-Hornillos, P. J. R. Mason, E. Ganogliu, Volker Sonnenschein, Jorge Agramunt, V. Vedia, A.-A. Zakari-Issoufou, Sami Rinta-Antila, R. Caballero-Folch, C. Weber, P. H. Regan, J. L. Tain, M. Estienne, M. D. Jordan, M. Monserrate, M. Lebois, Heikki Penttilä, Viki-Veikko Elomaa, V. M. Bui, E. Valencia, Ilkka Pohjalainen, A. Algora, Jani Hakala, Stephen Rice, T. Shiba, S.E.A. Orrigo, A. R. García, Jean-Christophe Sublet, S. Cormon, G. F. Farrelly, Zs. Podolyák, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Plompen, A, Hambsch, FJ, Schillebeeckx, P, Mondelaers, W, Heyse, J, Kopecky, S, Siegler, P, Oberstedt, S, Helsinki Institute of Physics, Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Plompen, A., Hambsch, F.-J., Schillebeeckx, P., Mondelaers, W., Heyse, J., Kopecky, S., Siegler, P., Oberstedt, S., Laboratoire de physique subatomique et des technologies associées ( SUBATECH ), IMT Atlantique Bretagne-Pays de la Loire ( IMT Atlantique ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Nantes ( UN ), Institut de Physique Nucléaire d'Orsay ( IPNO ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Total absorption spectroscopy, Fission, QC1-999, CHOOZ, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, 114 Physical sciences, Spectral line, law.invention, Physics::Geophysics, Nuclear physics, law, nuclear masses, 0103 physical sciences, structure, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Physics, Fission products, ta114, 010308 nuclear & particles physics, Pressurized water reactor, Nuclear data, Pandemonium effect, PRODUCTS, 13. Climate action, decay data measurements
Abstract

International audience; The accurate determination of reactor antineutrino spectra remains a very active research topic for which new methods of study have emerged in recent years. Indeed, following the long-recognized reactor anomaly (measured antineutrino deficit in short baseline reactor experiments when compared with spectral predictions), the three international reactor neutrino experiments Double Chooz, Daya Bay and Reno have recently demonstrated the existence of spectral distortions in their measurements with respect to the same predictions. These spectral predictions were obtained through the conversion of integral beta-energy spectra obtained at the ILL research reactor. Several studies have shown that the underlying nuclear physics required for the conversion of these spectra into antineutrino spectra is not totally understood. An alternative to such converted spectra is a complementary approach that consists of determining the antineutrino spectrum by means of the measurement and processing of nuclear data. The beta properties of some key fission products suffer from the pandemonium effect which can be circumvented by the use of the Total Absorption Gamma-ray Spectroscopy technique (TAGS). The two main contributors to the Pressurized Water Reactor antineutrino spectrum in the region where the spectral distortion has been observed are 92Rb and 142Cs, which have been measured at the radioactive beam facility of the University of Jyväskylä in two TAGS experiments. We present the results of the analysis of the TAGS measurements of the β-decay properties of 92Rb along with preliminary results on 142Cs and report on the measurements already performed.

Published
2016

13. Characterization of a neutron-beta counting system with beta-delayed neutron emitters

Author

V. Gorlychev, Dmitry Gorelov, W. Gelletly, M. B. Gómez-Hornillos, Juho Rissanen, Zs. Podolyák, D. Cano-Ott, G. Cortes, R. Caballero-Folch, Iain Moore, Anu Kankainen, P. J. R. Mason, C. Domingo-Pardo, Antti Saastamoinen, A. Riego, J. L. Tain, Tommi Eronen, F. Calviño, Ari Jokinen, T. Martinez, B. Rubio, M. D. Jordan, Heikki Penttilä, Mikael Reponen, C. Pretel, Ariel Tarifeño-Saldivia, E. Valencia, A. Algora, A. R. García, H. Hakala, J. Agramunt, L. Kucuk, F. Albiol, V. Kolhinen, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, and Universitat Politècnica de Catalunya. NERG - Grup de Recerca d'Enginyeria Nuclear

Subjects
Nuclear and High Energy Physics, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Montecarlo, Mètode de, 01 natural sciences, Self-triggered digital data acquisition system, Nuclear physics, Neutron and beta counters, 0103 physical sciences, Geant4 simulations, Neutron cross section, Neutron detection, Neutron, self-triggered digital data acquisition system, 010306 general physics, Nuclear Experiment, Instrumentation, Beta-delayed neutron emission probability, Physics, Bonner sphere, beta-delayed neutron emission probability, Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, ta114, ta213, 010308 nuclear & particles physics, Neutron stimulated emission computed tomography, Neutron temperature, Monte Carlo method, Física::Física molecular [Àrees temàtiques de la UPC], Delayed neutron, neutron and beta counters
Abstract

A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known β-delayed neutron emission properties. The setup consists of BELEN-20, a 4π neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for β counting and a self-triggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emission windows allowed the study of the effect of energy dependency on neutron, β and β–neutron rates. The observed effect is well reproduced by Monte Carlo simulations. The impact of this dependency on the accuracy of neutron emission probabilities is discussed. A new accurate value of the neutron emission probability for the important delayed-neutron precursor 137I was obtained, P n = 7.76 ( 14 ) %.

Published
2016

14. Persistence of collective behavior at high spin in theN=88nucleusTb153

Author

J. Simpson, E. S. Paul, M. A. Riley, T. Lauritsen, P. J. Nolan, D. C. Radford, J. P. Revill, J. Ollier, P. Hampson, J. M. Rees, R. V. F. Janssens, F. G. Kondev, U. Garg, Marina Petri, S. Zhu, Saul L. Miller, A. D. Ayangeakaa, Martin Carpenter, P. J. R. Mason, Ingemar Ragnarsson, J. T. Matta, D. J. Hartley, C. J. Chiara, Xuejun Wang, Calem Hoffman, and L. L. Riedinger

Subjects
Physics, Nuclear and High Energy Physics, Collective behavior, medicine.anatomical_structure, Spins, Excited state, Yrast, medicine, Gammasphere, Atomic physics, Nucleus, Line (formation), Spin-½
Abstract

Excited states in the N = 88 nucleus Tb-153 were observed up to spin similar to 40 in an experiment utilizing the Gammasphere array. The Tb-153 states were populated in a weak alpha 4n evaporation channel of the Cl-37 + Sn-124 reaction. Two previously known sequences were extended to higher spins, and a new decoupled structure was identified. The pi h(11/2) band was observed in the spin region where other N = 88 isotopes exhibit effects of prolate to oblate shape changes leading to band termination along the yrast line, whereas Tb-153 displays a persistent collective behavior. However, minor perturbations of the very highest state in both signatures of this h(11/2) band are observed, which perhaps signal the start of the transition towards band termination. (Less)

Published
2015

15. High-spin terminating states in theN=88Ho155andEr156isotones

Author

R. V. F. Janssens, D. C. Radford, J. Ollier, J. P. Revill, D. J. Hartley, P. J. R. Mason, J. Simpson, J. T. Matta, C. J. Chiara, T. Lauritsen, Martin Carpenter, F. G. Kondev, Ingemar Ragnarsson, A. D. Ayangeakaa, E. S. Paul, P. J. Nolan, Xuejun Wang, P. Hampson, Saul L. Miller, S. Zhu, Jnaneswari Gellanki, J. M. Rees, Calem Hoffman, U. Garg, Marina Petri, and M. A. Riley

Subjects
Physics, Nuclear and High Energy Physics, Normalization property, medicine.anatomical_structure, medicine, Shell (structure), Atomic physics, Spin (physics), Nucleus, Excitation
Abstract

The Sn-124(Cl-37, 6n gamma) fusion-evaporation reaction at a bombarding energy of 180 MeV has been used to significantly extend the excitation level scheme of Ho-155(67)88. The collective rotational behavior of this nucleus breaks down above spin I similar to 30 and a fully aligned noncollective (band terminating) state has been identified at I-pi = 79/2(-). Comparison with cranked Nilsson-Strutinsky calculations also provides evidence for core-excited noncollective states at I-pi = 87/2(-) and (89/2(+)) involving particle-hole excitations across the Z = 64 shell gap. A similar core-excited state in Er-156(68)88 at I-pi = (46(+)) is also presented.

Published
2015

16. Spectroscopy ofHf161from low to high spin

Author

Kalle Auranen, Joonas Konki, Ulrika Jakobsson, Pauli Peura, J. P. Wrigh, C. McPeake, Juha Sorri, K. Villafani, Philippos Papadakis, Sanna Stolze, A. J. Boston, Catherine Scholey, Mikael Sandzelius, Panu Ruotsalainen, D. T. Joss, Jan Sarén, J. Simpson, Jill S. Baron, J.F. Sharpey-Schafer, F. Wearing, E. S. Paul, Tuomas Grahn, G. J. O'Neill, Jari Partanen, Janne Pakarinen, S. L. Miller, H. Badran, Juha Uusitalo, M. A. Riley, Paul Greenlees, Rauno Julin, T. R. Davis-Merry, Matti Leino, Andrej Herzan, Sakari Juutinen, L. Sinclair, Panu Rahkila, and P. J. R. Mason

Subjects
Physics, Nuclear and High Energy Physics, Nuclear magnetic resonance, Excited state, Quasiparticle, Side band, Atomic physics, Spectroscopy, Ground state, Spin-½
Abstract

Excited states in the neutron-deficient nucleus $_{72}^{161}\mathrm{Hf}_{89}$ have been populated using the $^{118}\mathrm{Sn}(^{48}\mathrm{Ti},5n)^{161}\mathrm{Hf}$ and $^{110}\mathrm{Pd}(^{56}\mathrm{Fe},5n)^{161}\mathrm{Hf}$ fusion-evaporation reactions at 240 and 270 MeV, respectively. The level scheme for $^{161}\mathrm{Hf}$ has been extended with the observation of new band structures and an ${I}^{\ensuremath{\pi}}=(13/{2}^{+})$ isomeric state with a half-life of 4.8(2) $\ensuremath{\mu}\mathrm{s}$ has been identified. The decay path from this isomer to the $(7/{2}^{\ensuremath{-}})$ ground state is established. The yrast band, based on the $(13/{2}^{+})$ isomeric state, is extended up to $(73/{2}^{+})$ and side band structures are identified up to $(69/{2}^{\ensuremath{-}})$ and $(55/{2}^{\ensuremath{-}})$. Quasiparticle assignments for these rotational structures are made on the basis of their alignment properties and Woods-Saxon cranked shell-model calculations.

Published
2014

17. Recent Results at Ultrahigh Spin: Terminating States and Beyond in Mass 160 Rare-earth Nuclei

Author

D. J. Hartley, E. S. Paul, A. D. Ayangeakaa, M. A. Riley, J. P. Revill, Jill S. Baron, Martin Carpenter, R. V. F. Janssens, J. Simpson, Calem Hoffman, P. J. Nolan, Saul L. Miller, U. Garg, P. J. R. Mason, Marina Petri, S. Zhu, J. Ollier, Xuejun Wang, C. J. Chiara, P. Hampson, J. M. Rees, T. Lauritsen, F. G. Kondev, J. T. Matta, D. C. Radford, and Ingemar Ragnarsson

Subjects
Rare earth nuclei, Physics, Normalization property, Valence (chemistry), Oblate spheroid, General Physics and Astronomy, Atomic physics, Nucleon
Abstract

A classic region of band termination at high spin occurs in rare-earth nuclei with around ten valence nucleons above the Gd-146 closed core. Results are presented here for such non-collective oblate (gamma = 60 degrees) terminating states in odd-Z Ho-155, odd-odd Ho-156, and even-even Er-156, where they are compared with neighbouring nuclei. In addition to these particularly favoured states, the occurrence of collective triaxial strongly deformed (TSD) bands, bypassing the terminating states and extending to over 65 (h) over bar, is reviewed.

Published
2015

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