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1. Total absorption gamma-ray spectroscopy study of the β-decay of 186Hg

Author

A. Algora, E. Ganioğlu, P. Sarriguren, V. Guadilla, L.M. Fraile, E. Nácher, B. Rubio, J.L. Tain, J. Agramunt, W. Gelletly, J.A. Briz, R.B. Cakirli, M. Fallot, D. Jordán, Z. Halász, I. Kuti, A. Montaner, A. Onillon, S.E.A. Orrigo, A. Perez Cerdan, S. Rice, V. Vedia, and E. Valencia

Subjects
Beta decay, Total absorption spectroscopy, Shape coexistence, Physics, QC1-999
Abstract

The Gamow-Teller strength distribution of the decay of 186Hg into 186Au has been determined for the first time using the total absorption gamma spectroscopy technique and has been compared with theoretical QRPA calculations using the SLy4 Skyrme force. The measured Gamow-Teller strength distribution and the half-life are described by mixing oblate and prolate configurations independently in the parent and daughter nuclei. In this theoretical framework the best description of the experimental beta strength is obtained with dominantly prolate components for both parent 186Hg and daughter 186Au. The approach also allowed us to determine an upper limit of the oblate component in the parent state. The complexity of the analysis required the development of a new approach in the analysis of the X-ray gated total absorption spectrum.

Published
2021
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2. Investigation of the Δn = 0 selection rule in Gamow-Teller transitions: The β-decay of 207Hg

Author

T.A. Berry, Zs. Podolyák, R.J. Carroll, R. Lică, H. Grawe, N.K. Timofeyuk, T. Alexander, A.N. Andreyev, S. Ansari, M.J.G. Borge, J. Creswell, C. Fahlander, L.M. Fraile, H.O.U. Fynbo, W. Gelletly, R.-B. Gerst, M. Górska, A. Gredley, P. Greenlees, L.J. Harkness-Brennan, M. Huyse, S.M. Judge, D.S. Judson, J. Konki, J. Kurcewicz, I. Kuti, S. Lalkovski, I. Lazarus, M. Lund, M. Madurga, N. Mărginean, R. Mărginean, I. Marroquin, C. Mihai, R.E. Mihai, E. Nácher, S. Nae, A. Negret, C. Niţă, R.D. Page, S. Pascu, Z. Patel, A. Perea, V. Pucknell, P. Rahkila, E. Rapisarda, P.H. Regan, F. Rotaru, C.M. Shand, E.C. Simpson, Ch. Sotty, S. Stegemann, T. Stora, O. Tengblad, A. Turturica, P. Van Duppen, V. Vedia, R. Wadsworth, P.M. Walker, N. Warr, F. Wearing, and H. De Witte

Subjects
Physics, QC1-999
Abstract

Gamow-Teller β decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This Δn=0 requirement plays a major role in the β decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical r-process pathway below both Z=50 (for N>82) and Z=82 (for N>126). The level of forbiddenness of the Δn=1ν1g9/2→π0g7/2 transition has been investigated from the β− decay of the ground state of 207Hg into the single-proton-hole nucleus 207Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible γ-ray transitions depopulating the π0g7/2−1 state in 207Tl, an upper limit of 3.9×10−3% was obtained for the probability of this decay, corresponding to log⁡ft>8.8 within a 95% confidence limit. This is the most stringent test of the Δn=0 selection rule to date.

Published
2019
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3. Multi-quasiparticle sub-nanosecond isomers in 178W

Author

M. Rudigier, P.M. Walker, R.L. Canavan, Zs. Podolyák, P.H. Regan, P.-A. Söderström, M. Lebois, J.N. Wilson, N. Jovancevic, A. Blazhev, J. Benito, S. Bottoni, M. Brunet, N. Cieplicka-Orynczak, S. Courtin, D.T. Doherty, L.M. Fraile, K. Hadynska-Klek, M. Heine, Ł.W. Iskra, J. Jolie, V. Karayonchev, A. Kennington, P. Koseoglou, G. Lotay, G. Lorusso, M. Nakhostin, C.R. Nita, S. Oberstedt, L. Qi, J.-M. Régis, V. Sánchez-Tembleque, R. Shearman, W. Witt, V. Vedia, and K.O. Zell

Subjects
Physics, QC1-999
Abstract

We report on the first measurement of the half-lives of Kπ=11− and 12+ four-quasiparticle states in the even-even nucleus 178W. The sub-nanosecond half-lives were measured by applying the centroid shift method to data taken with LaBr3(Ce) scintillator detectors of the NuBall array at the ALTO facility in Orsay, France. The half-lives of these states only became experimentally accessible by the combination of several experimental techniques - scintillator fast timing, isomer spectroscopy with a pulsed beam, and the event-by-event calorimetry information provided by the NuBall array. The measured half-lives are 476(44)ps and 275(65)ps for the Iπ=11− and 12+ states, respectively. The decay transitions include weakly hindered E1 and E2 branches directly to the ground-state band, bypassing the two-quasiparticle states. This is the first such observation for an E1 transition. The interpretation of the small hindrance hinges on mixing between the ground-state band and the t-band.

Published
2020
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4. The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus 133Sb

Author

G. Bocchi, S. Leoni, B. Fornal, G. Colò, P.F. Bortignon, S. Bottoni, A. Bracco, C. Michelagnoli, D. Bazzacco, A. Blanc, G. de France, M. Jentschel, U. Köster, P. Mutti, J.-M. Régis, G. Simpson, T. Soldner, C.A. Ur, W. Urban, L.M. Fraile, R. Lozeva, B. Belvito, G. Benzoni, A. Bruce, R. Carroll, N. Cieplicka-Oryǹczak, F.C.L. Crespi, F. Didierjean, J. Jolie, W. Korten, T. Kröll, S. Lalkovski, H. Mach, N. Mărginean, B. Melon, D. Mengoni, B. Million, A. Nannini, D. Napoli, B. Olaizola, V. Paziy, Zs. Podolyák, P.H. Regan, N. Saed-Samii, B. Szpak, and V. Vedia

Subjects
Neutron induced fission, Gamma spectroscopy, Nuclear state lifetime, Large Ge array, Particle-core couplings, Physics, QC1-999
Abstract

The γ-ray decay of excited states of the one-valence-proton nucleus 133Sb has been studied using cold-neutron induced fission of 235U and 241Pu targets, during the EXILL campaign at the ILL reactor in Grenoble. By using a highly efficient HPGe array, coincidences between γ-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 μs isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr3(Ce) scintillators, revealed a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus 132Sn and the valence proton, using the Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin.

Published
2016
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5. Results of DTAS Campaign at IGISOL : Overview

Author

V. Guadilla, A. Algora, M. Fallot, J.L. Tain, J. Agramunt, J. Äystö, J.A. Briz, A. Cucoanes, T. Eronen, M. Estienne, L.M. Fraile, E. Ganioğlu, W. Gelletly, D. Gorelov, J. Hakala, A. Jokinen, D. Jordan, A. Kankainen, V. Kolhinen, J. Koponen, M. Lebois, L. Le Meur, T. Martinez, M. Monserrate, A. Montaner-Pizá, I. Moore, E. Nácher, S.E.A. Orrigo, H. Penttilä, I. Pohjalainen, A. Porta, J. Reinikainen, M. Reponen, S. Rinta-Antila, B. Rubio, K. Rytkönen, T. Shiba, V. Sonnenschein, A.A. Sonzogni, E. Valencia, V. Vedia, A. Voss, J.N. Wilson, A.-A. Zakari-Issoufou, Matejska-Minda, M., Bednarczyk, P., and Kmiecik, M.

Subjects
spektrometria, tutkimuslaitteet, spektrometrit, General Physics and Astronomy, ydinfysiikka
Abstract

The β decays of more than twenty fission fragments were measured in the first experiments with radioactive-ion beams employing the Decay Total Absorption γ-ray Spectrometer. In this work, we summarize the main results obtained so far from this experimental campaign carried out at the Ion Guide Isotope Separator On-Line facility. The advances introduced for these studies represent the state-of-the-art of our analysis methodology for segmented spectrometers. peerReviewed

Published
2023

6. First Report of a Doublet 2209-keV State in $^{100}$Zr

Author

D. Kalaydjieva, P.E. Garrett, H. Bidaman, M. Rocchini, M. Zielińska, W. Korten, V. Bildstein, S. Pannu, Z. Ahmed, C. Andreoiu, D. Annen, G.C. Ball, G. Benzoni, S.S. Bhattacharjee, S. Buck, R.J. Coleman, S. Devinyak, I. Dillmann, R. Caballero-Folch, F.H. Garcia, A.B. Garnsworthy, B. Greaves, C.J. Griffin, G.F. Grinyer, E. Gyabeng Fuakye, G. Hackman, D. Hymers, R. Kanungo, K. Kapoor, E. Kasanda, N. Marchini, K.M. Mashtakov, A. Nannini, C. Natzke, B. Olaizola, K. Ortner, C.M. Petrache, M. Polettini, A.J. Radich, N. Saei, M. Satrazani, M. Siciliano, M. Singh, P. Spagnoletti, C.E. Svensson, D.A. Torres, R. Umashankar, V. Vedia, T. Zidar, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract

International audience; A β-decay experiment aiming at investigation of the low-spin structure of 100Zr was performed using the GRIFFIN spectrometer at TRIUMFISAC. Based on the obtained data, a new 2 + state is postulated which is degenerate in energy with the established (5+) level at 2209 keV.

Published
2022

7. Total absorption γ -ray spectroscopy of the β decays of Y96gs,m

Author

V. Guadilla, L. Le Meur, M. Fallot, J. A. Briz, M. Estienne, L. Giot, A. Porta, A. Cucoanes, T. Shiba, A.-A. Zakari-Issoufou, A. Algora, J. L. Tain, J. Agramunt, D. Jordan, M. Monserrate, A. Montaner-Pizá, E. Nácher, S. E. A. Orrigo, B. Rubio, E. Valencia, J. Äystö, T. Eronen, D. Gorelov, J. Hakala, A. Jokinen, A. Kankainen, V. Kolhinen, J. Koponen, I. Moore, H. Penttilä, I. Pohjalainen, J. Reinikainen, M. Reponen, S. Rinta-Antila, K. Rytkönen, V. Sonnenschein, A. Voss, L. M. Fraile, V. Vedia, E. Ganioğlu, W. Gelletly, M. Lebois, J. N. Wilson, T. Martinez, and A. A. Sonzogni

Published
2022

8. Advanced scintillators for fast-timing applications

Author

J. Benito, V. Vedia, L. M. Fraile, V. Sánchez-Tembleque, J. M. Udías, and M. García-Díez

Subjects
Nuclear and High Energy Physics, Signal processing, Materials science, business.industry, Nuclear state, 02 engineering and technology, Scintillator, 021001 nanoscience & nanotechnology, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Data acquisition, Optoelectronics, Gamma spectroscopy, 0210 nano-technology, business, Hpge detector, Instrumentation, Energy (signal processing), Effective atomic number
Abstract

Gamma spectroscopy has been recast by a new generation of inorganic scintillators, mostly halide compounds, with large effective atomic number, excellent timing properties and a good energy resolution. The most prominent example is LaBr3(Ce), commercially available for more than a decade. The impact of LaBr3(Ce) in fast-timing experiments dedicated to measure nuclear state lifetimes has been tremendous. In fact, it has been the key player in the development of fast-timing with mixed arrays of HPGe detectors and fast scintillators. In this contribution we discuss the main parameters affecting the precision of timing measurements. We describe the evaluation of a newly-available LaBr3(Ce+Sr) crystal for fast-timing applications, and compare the time and energy resolutions to a well-established LaBr3(Ce) of the same size and shape. The measurements are performed using a fully-digital signal processing data acquisition system, which has been proven to yield even better results than standard analog acquisition systems.

Published
2020

9. Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Physics and Nuclear Structure and Astrophysics

Author

Magali Estienne, V. Guadilla, M. Fallot, A. Algora, J. L. Taín, A. Porta, L. Giot, J. A. Briz, V. M. Bui, S. Cormon, D. Jordan, L. Le Meur, S. Rice, E. Valencia, A.-A. Zakari-Issoufou, J. Agramunt, J. Äystö, A. Cucoanes, T. Eronen, L. M. Fraile, E. Ganioglu, W. Gelletly, D. Gorelov, J. Hakala, A. Jokinen, A. Kankainen, V. Kolhinen, J. Koponen, M. Lebois, T. Martinez, M. Monserrate, A. Montaner-Pizá, I. Moore, E. Nácher, S. E. A. Orrigo, H. Penttilä, S. Péru, I. Pohjalainen, J. Reinikainen, M. Reponen, S. Rinta-Antila, B. Rubio, K. Rytkönen, T. Shiba, V. Sonnenschein, A. A. Sonzogni, V. Vedia, A. Voss, and J. N. Wilson

Subjects
General Medicine
Abstract

The accurate determination of reactor antineutrino spectra remains a very hot research topic, where new questions have emerged in recent years. Indeed, after the “reactor anomaly” – a deficit of measured antineutrinos at short baseline reactor experiments with respect to spectral predictions – the three international reactor neutrino experiments Double Chooz, Daya Bay and Reno have evidenced spectral distortions in their measurements with respect to the same spectral predictions. This puzzle is called the “shape anomaly”. Recently summation calculations of reactor antineutrino spectra based on the use of nuclear data have obtained the best agreement to date with the reactor neutrino flux measurements at the level of 2% thanks to a decade of Total Absorption Gamma-ray Spectroscopy (TAGS) measurements at the radioactive beam facility of the University of Jyväskylä in two experimental campaigns. A selection of the results obtained so far is presented.

Published
2023

10. Total absorption gamma-ray spectroscopy study of the β-decay of 186Hg

Author

Berta Rubio, J. L. Tain, L. M. Fraile, Jorge Agramunt, Enrique Nácher, E. Valencia, A. Perez Cerdan, R. B. Cakirli, W. Gelletly, E. Ganioglu, Stephen Rice, V. Guadilla, István Kuti, A. Onillon, V. Vedia, Zoltán Halász, M. Fallot, S. E. A. Orrigo, José Antonio Briz, Pedro Sarriguren, A. Algora, D. Jordan, A. Montaner, SCOAP, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Nuclear Science and Applications Research, European Commission, Organisation for Economic Co-operation and Development, Max Planck Society, Science and Technology Facilities Council (UK), National Science Centre (Poland), National Research, Development and Innovation Office (Hungary), Ministerio de Ciencia, Innovación y Universidades (España), 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), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Physics, Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Absorption spectroscopy, Total absorption spectroscopy, 010308 nuclear & particles physics, QC1-999, Shape coexistence, Beta decay, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, 3. Good health, Distribution (mathematics), Beta (plasma physics), 0103 physical sciences, Gamma spectroscopy, Atomic physics, 010306 general physics, Absorption (electromagnetic radiation), Mixing (physics)
Abstract

7 pags., 9 figs., 1 tab., The Gamow-Teller strength distribution of the decay of Hg into Au has been determined for the first time using the total absorption gamma spectroscopy technique and has been compared with theoretical QRPA calculations using the SLy4 Skyrme force. The measured Gamow-Teller strength distribution and the half-life are described by mixing oblate and prolate configurations independently in the parent and daughter nuclei. In this theoretical framework the best description of the experimental beta strength is obtained with dominantly prolate components for both parent Hg and daughter Au. The approach also allowed us to determine an upper limit of the oblate component in the parent state. The complexity of the analysis required the development of a new approach in the analysis of the X-ray gated total absorption spectrum., This work was supported by Spanish Ministerio de Economía y Competitividad under grants FPA2011-24553, FPA2014-52823-C2-1-P, FPA2017-83946-C2-1-P, FPA2017-87568-P, Ministerio de Ciencia e Innovación grants PID2019-104714GB-C21 and RTI2018-098868-B-100, program Severo Ochoa (SEV-2014-0398), ENSAR (grant 262010) and by the European Union Horizon 2020 research and innovation programme under Grant Agreement No. 654002. S.E.A.O. thanks the support of CPAN Consolider-Ingenio 2010 Programme CSD2007-00042 grant. E.G. acknowledges support from TÜBITAK 2219 Abroad Research Fellowship Programme. R.B.C. acknowledges support by the Max-Planck-Partner group. Support from the technical staff and engineers of ISOLDE-CERN is acknowl- edged. W.G. acknowledges the support of STFC (UK) council grant ST/P005314/1. V.G. acknowledges the support of the National Science Center, Poland, under Contract No. 2019/35/D/ST2/02081. This work was also supported by the National Research, Development and Innovation Fund of Hungary, financed under the K18 funding scheme with Projects No. K 128729 and NN128072. P.S. acknowledges support from MCI/AEI/FEDER, UE (Spain) under grant PGC2018-093636-B-I00

Published
2021

11. Competition between allowed and first-forbidden β decays of At208 and expansion of the Po208 level scheme

Author

L. J. Harkness-Brennan, I. Marroquin, Raymond J. Carroll, Zs. Podolyák, E. Rapisarda, R. Shearman, S. Vinals, J. Konki, C. Sotty, R. Mărginean, A. N. Andreyev, Edward Simpson, R. Lica, J. Kurcewicz, J. G. Cubiss, L. M. Fraile, P. Rahkila, A. Negret, Paul Greenlees, M. Piersa, H. O. U. Fynbo, Olof Tengblad, S. Pascu, P. H. Regan, F. Rotaru, Ángel Perea, V. Vedia, Marc Huyse, M. J. G. Borge, I.H. Lazarus, N. Marginean, V. F. E. Pucknell, Robert Page, B. A. Brown, R. Wadsworth, P. Van Duppen, D. S. Judson, C. Mihai, M. Rudigier, T. Berry, M. Madurga, Enrique Nácher, Thierry Stora, H. De Witte, C. M. Shand, N. Warr, J. Phrompao, E.R. Gamba, and M. Brunet

Subjects
Physics, 010308 nuclear & particles physics, SHELL model, 01 natural sciences, Core (optical fiber), Nucleosynthesis, Position (vector), Beta (plasma physics), Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Excitation
Abstract

The structure of Po-208 populated through the EC/beta(+) decay of At-208 is investigated using gamma-ray spectroscopy at the ISOLDE Decay Station. The presented level scheme contains 27 new excited states and 43 new transitions, as well as a further 50 previously observed. rays which have been (re)assigned a position. The level scheme is compared to shell model calculations. Through this analysis approximately half of the beta-decay strength of At-208 is found to proceed via allowed decay and half via first-forbidden decay. The first-forbidden transitions predominantly populate core excited states at high excitation energies, which is qualitatively understood using shell model considerations. This mass region provides an excellent testing ground for the competition between allowed and first-forbidden beta-decay calculations, important for the detailed understanding of the nucleosynthesis of heavy elements.

Published
2021

12. Investigation of the Δn = 0 selection rule in Gamow-Teller transitions: The β-decay of 207Hg

Author

Mark Huyse, Claes Fahlander, Edward Simpson, R. Lica, F. Rotaru, A. Negret, R. Wadsworth, C. Sotty, H. O. U. Fynbo, István Kuti, Ángel Perea, Olof Tengblad, N.K. Timofeyuk, María José García Borge, M. V. Lund, A. Gredley, W. Gelletly, R. Mărginean, Raymond J. Carroll, C. R. Niţă, Zena Patel, R. E. Mihai, V. Vedia, Philip M Walker, Zs. Podolyák, C. Mihai, Miguel Madurga, E. Rapisarda, F. Wearing, Joonas Konki, S. Lalkovski, P. Van Duppen, I. Marroquin, V. F. E. Pucknell, H. De Witte, T. Alexander, Panu Rahkila, I.H. Lazarus, J. Creswell, L. M. Fraile, Paul Greenlees, S. Ansari, P. H. Regan, L. J. Harkness-Brennan, N. Marginean, T. Berry, Thierry Stora, R. B. Gerst, S. M. Judge, C. M. Shand, Enrique Nácher, S. Pascu, A. Turturica, S. Stegemann, Andrei Andreyev, N. Warr, S. Nae, R. D. Page, D. S. Judson, J. Kurcewicz, H. Grawe, M. Górska, European Commission, Science and Technology Facilities Council (UK), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Research Foundation - Flanders, University of Leuven, Belgian Science Policy Office, Helmholtz-Zentrum Berlin for Materials and Energy, National Measurement Office (UK), and SCOAP

Subjects
Physics, Nuclear and High Energy Physics, ta114, 010308 nuclear & particles physics, State (functional analysis), 01 natural sciences, lcsh:QC1-999, Nuclear physics, medicine.anatomical_structure, Nucleosynthesis, 0103 physical sciences, medicine, Nuclear Physics - Experiment, Limit (mathematics), Gamow-Teller transitions, ydinfysiikka, 010306 general physics, Ground state, Wave function, Nuclear Experiment, Nucleus, lcsh:Physics
Abstract

5 pags., 3 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0, Gamow-Teller β decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This Δn=0 requirement plays a major role in the β decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical r-process pathway below both Z=50 (for N>82) and Z=82 (for N>126). The level of forbiddenness of the Δn=1ν1g →π0g transition has been investigated from the β decay of the ground state of Hg into the single-proton-hole nucleus Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible γ-ray transitions depopulating the π0g state in Tl, an upper limit of 3.9×10 % was obtained for the probability of this decay, corresponding to log⁡ft>8.8 within a 95% confidence limit. This is the most stringent test of the Δn=0 selection rule to date., Support from the European Union seventh framework through ENSAR contract no. 262010, the Science and Technology Facilities Council through grants ST/P005314/1, ST/L005743/1 and ST/J000051/1 (UK), the MINECO projects FPA2015-64969-P, FPA2015-65035-P and FPA2017-87568-P (Spain), FWO-Vlaanderen (Belgium), GOA/2015/010 (BOF KU Leuven), the Excellence of Science programme (EOS-FWO), and the Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (BriX network P7/12) is acknowledged. ZsP acknowledges support by the ExtreMe Matter Institute EMMI at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. PHR and SMJ ac-knowledge support from the UK Department for Business, Energy and Industrial Strategy via the National Measurement Office.

Published
2019

13. Optimizing time-pickup algorithms in radiation detectors with a genetic algorithm

Author

L. M. Fraile, J. M. Udías, V. Vedia, Stefan Ritt, and V. Sánchez-Tembleque

Subjects
Physics, Nuclear and High Energy Physics, Photomultiplier, 010308 nuclear & particles physics, business.industry, Detector, Dynode, Constant fraction discriminator, 01 natural sciences, Particle detector, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Data acquisition, 0103 physical sciences, business, Instrumentation, Digital filter, Algorithm, Digital signal processing
Abstract

Pulse digitization at high rates has paved the way for the use of complex, non-standard algorithms, beyond the conventional constant fraction discriminator (CFD) option to obtain the time-stamps of gamma photons arriving to nuclear detectors. Detector pulses can be shaped with digital filters in digital signal processing (DSP) hardware or software, and timestamps can be derived by interpolating or extrapolating the acquired samples. Digitized pulses can be stored in a computer for off-line analysis allowing for many different algorithm variations to be tried on the same data. One difficulty is that the number of filters and parameters to be tuned in order to optimize the timing performance may become too large to be done by hand. For this, in this work we use a genetic algorithm to tune in-silico digital filters, digital time pickup algorithms and their associated parameters. The data set consisted of 500,000 pulses obtained from the last dynode of two ultrafast photomultiplier tubes (model R9779 by Hamamatsu) coupled to monolithic fast inorganic LaBr 3 (Ce) scintillators , in a truncated cone geometry 1.5 × 1 × 1.5” . With finely tuned conventional (CFD+TAC) timing electronics, a CRT of 155 ps (FWHM) for a 60Co source has been measured by our group, within the state of the art for detectors of this size. Our alternate digital, in-silico implementation of CFD+TAC, fine-tuned with the same parameters obtained during manual adjustment of the conventional DAQ and applied to pulses digitized at 5 GS/s and 14 bits of vertical resolution, reproduces the performance of the conventional DAQ. On the other hand, a genetic algorithm (GA) is employed to optimize digital recursive filters with up to 8 parameters, and different time-pickup strategies (upper level thresholding, CFD, time extrapolation). The same 500,000 pulses are employed for which the GA finds several families of filters outperforming the manually tuned algorithm by more than 10%.

Published
2019

14. Spectroscopy and lifetime measurements in Te134,136,138 isotopes and implications for the nuclear structure beyond N=82

Author

D. Verney, D. Ralet, J. Wiederhold, S. Bottoni, L. Matthieu, B. Fornal, A. Blazhev, P. H. Regan, C. Schmitt, R.L. Canavan, K. Rezynkina, D. Reygadas Tello, A. Lopez-Martens, K. Hauschild, B. Wasilewska, I. Matea, A. Korgul, C. Henrich, J. Jolie, V. Guadilla, M. Lebois, M. Babo, Th. Kröll, L. M. Fraile, J. Benito, G. Benzoni, T. Kurtukian-Nieto, L. Qi, Stephan Oberstedt, C. Porzio, M. Bunce, N. Warr, R. B. Gerst, P. A. Söderström, Y. Popovitch, W. Paulsen, F. Ibrahim, Ł. W. Iskra, G. Häfner, J. N. Wilson, S. Jazwari, M. S. Yavahchova, R. Chakma, C. Delafosse, A. Boso, R. Lozeva, N. Jovančević, V. Sanchez, H. Naïdja, M. Rudigier, P. Adsley, L. Le-meur, N. Cieplicka-Oryńczak, I. Homm, E. Adamska, G. Tocabens, K. Belvedere, D. Gjestvang, D. Thisse, M. L. Cortés, P. Koseoglou, P. Davies, V. Vedia, J. Nemer, M. Piersa, Muriel Fallot, C. Sürder, K. Miernik, S. M. Collins, S. Ziliani, D. Etasse, Fabio Zeiser, and J. Ljungvall

Subjects
Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, Fission, Nuclear structure, Context (language use), 7. Clean energy, 01 natural sciences, Excited state, 0103 physical sciences, Neutron source, Atomic physics, 010306 general physics, Spectroscopy
Abstract

We report on spectroscopic information and lifetime measurements of even-even neutron-rich Te isotopes. Excited states were populated in fast-neutron induced fission of U238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid ν-ball spectrometer. We provide first results on lifetimes of the 61+ state in Te136 and the (61+), (41+), and (21+) states in Te138 and discuss the results in the context of large-scale shell-model calculations. The level schemes of Te136 and Te138 are revised in terms of lifetimes of their 21+,41+ states and updated information on the (42+) state in Te136 is presented. In addition, previously reported data on spectroscopy and lifetimes in Te134 are reexamined. This work provides new insights into the evolution of collectivity for Te isotopes with N=82,84,86.

Published
2021

15. Angular momentum generation in nuclear fission

Author

B. Fornal, M. S. Yavahchova, C. Delafosse, A. Boso, V. Sánchez-Tembleque, K. Rezynkina, M. Lebois, K. Hauschild, T. Kröll, Muriel Fallot, P. Adsley, J. Ljungvall, Ł. W. Iskra, F. Ibrahim, E. Adamska, C. Henrich, A. Gottardo, Stephan Oberstedt, R. Chakma, C. Sürder, V. Guadilla, C. Porzio, P. H. Regan, J. Benito, A. Korgul, R. Lozeva, L. Le Meur, M. Piersa, P. Ivanov, V. Vedia, J. Nemer, B. Wasilewska, N. Jovančević, Y. Popovitch, W. Paulsen, C. Schmitt, N. Cieplicka-Oryńczak, R. B. Gerst, Sunniva Siem, G. Tocabens, P. A. Söderström, K. Belvedere, S. Courtin, S. Ziliani, R. Canavan, D. Gjestvang, L. Qi, D. Etasse, P. Koseoglou, G. Häfner, I. Matea, I. Homm, M. Heine, L. M. Fraile, T. Kurtukian-Nieto, Fabio Zeiser, P. Davies, D. Thisse, M. L. Cortés, A. Blazhev, S. Jazrawi, M. Bunce, A. Lopez-Martens, K. Miernik, Alejandro Algora, M. Rudigier, J. N. Wilson, N. Warr, J. Wiederhold, D. Verney, D. Ralet, M. Babo, L. Gaudefroy, G. Benzoni, S. Bottoni, S. Leoni, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Oslo (UiO), Department of Physics, University of Surrey, University of Surrey (UNIS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CEA, Bruyeres le Chatel, France, affiliation inconnue, University of Warsaw (UW), Facultat de Fisica [València] (UV), Universitat de València (UV), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Università degli Studi di Milano = University of Milan (UNIMI), Institut für Kernphysik der Universität zu Köln, Universität zu Köln = University of Cologne, National Physical Laboratory [Teddington] (NPL), Instytut Fizyki Jądrowej PAN (IFJ), Polskiej Akademii Nauk, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), University of Manchester [Manchester], 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), European Commission - Joint Research Centre [Geel] (JRC), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Horia Hulubei Natl Inst Phys & Nucl Engn IFIN HH, ELI NP Dept, Reactorului Str 30, Magurele 077125, Romania, Софийски университет = Sofia University, Technische Universität Darmstadt (TU Darmstadt), Universidad Complutense de Madrid [Madrid] (UCM), Università degli studi di Milano [Milano], Universität zu Köln, Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes - Faculté des Sciences et des Techniques, 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), Technical University Darmstadt (TU), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), University of Sofia, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Università degli Studi di Milano [Milano] (UNIMI), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Direction des Applications Militaires (DAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, [PHYS]Physics [physics], Angular momentum, Multidisciplinary, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Spins, 010308 nuclear & particles physics, Fission, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Nuclear fission, 0103 physical sciences, Atomic nucleus, Nuclear Experiment, 010306 general physics, Nucleon, Excitation, ComputingMilieux_MISCELLANEOUS, Spin-½
Abstract

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4–12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18. γ-ray spectroscopy experiments on the origin of spin in the products of nuclear fission of spin-zero nuclei suggest that the fission fragments acquire their spin after scission, rather than before.

Published
2021

16. First lifetime investigations of $N>82$ iodine isotopes: The quest for collectivity

Author

A. Korgul, J. Wiederhold, Th. Kröll, S. Leoni, P. Adsley, Muriel Fallot, M. Babo, J. Benito, G. Benzoni, V. Vedia, K. Miernik, L. Qi, J. Nemer, V. Guadilla, C. Sürder, S. Bottoni, D. Verney, S. Jazwari, N. Warr, A. Boso, K. Rezynkina, D. Ralet, J. Ljungvall, F. Ibrahim, L. M. Fraile, T. Kurtukian-Nieto, M. Lebois, Fabio Zeiser, R. Chakma, A. Blazhev, P. H. Regan, R. Lozeva, C. Schmitt, L. Matthieu, R.L. Canavan, M. Piersa-Siłkowska, A. Algora, N. Jovančević, J. N. Wilson, Y. Popovitch, N. Cieplicka-Oryńczak, W. Paulsen, E. Adamska, G. Tocabens, P. Davies, K. Belvedere, D. Gjestvang, S. M. Collins, S. Ziliani, D. Etasse, M. Bunce, C. Henrich, R. B. Gerst, A. Lopez-Martens, M. Rudigier, Ł. W. Iskra, G. Häfner, B. Wasilewska, Stephan Oberstedt, C. Porzio, P. A. Söderström, C. Delafosse, V. Sánchez-Tembleque, L. Le-meur, H. Naïdja, M. S. Yavahchova, P. Koseoglou, I. Homm, D. Thisse, M. L. Cortés, D. Reygadas Tello, K. Hauschild, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ILL, and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, chemistry.chemical_element, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Iodine, 01 natural sciences, chemistry, Excited state, 0103 physical sciences, Neutron source, Física nuclear, Atomic physics, 010306 general physics
Abstract

International audience; We report on spectroscopic information and lifetime measurements in the neutron-rich I135,137,139 isotopes. This is the first lifetime data on iodine isotopes beyond N=82. Excited states were populated in fast neutron-induced fission of U238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid ν-ball spectrometer. The level schemes of the I135,137,139 isotopes are revised in terms of excited states with up to maximum spin-parity of (33/2+), populated for the first time in fast neutron-induced fission. We provide first results on the lifetimes of the (9/21+) and (13/21+) states in I137 and I139, and the (17/21+) state in I137. In addition, we give upper lifetime limits for the (11/21+) states in I135−139, the (15/21+) state in I137, the (17/21+) state in I139, and reexamine the (29/21+) state in I137. The isomeric data in I135 are reinvestigated, such as the previously known (15/21+) and (23/21−) isomers with T1/2 of 1.64(14) and 4.6(7) ns, respectively, as obtained in this work. The new spectroscopic information is compared to that from spontaneous or thermal-neutron induced fission and discussed in the context of large scale shell-model (LSSM) calculations for the region beyond Sn132, indicating the behavior of collectivity for the three valence-proton iodine chain with N=82,84,86.

Published
2021

17. The novel Mechanical Ventilator Milano for the COVID-19 pandemic

Author

M. Tardocchi, P. Lu, Silvia Bonfanti, C. Fricbergs, J. M. Cela Ruiz, M. Del Tutto, R. Brown, D. Salomoni, C. Jillings, A. Visioli, A. Abba, B. Smith, P. Stringari, Valerio Ippolito, K. Olchanski, S. Yue, A. Razeto, L. Parmeggiano, M. Beschi, I. Palumbo, C. C. James, M. Daley, Andrea Bombarda, Eugenio Scapparone, T. Boccali, D. Vonica, G. Luzón, E. Panontin, Nigel Hessey, E. Elliott, O. Putignano, R. Maharaj, M. H. L. S. Wang, M. Laclaustra, A. Sher, E. Gramellini, P. Napoli, S. Parmeggiano, E. Meazzi, S. Sala, A. Muraro, T. Girma, D. Trask, A. Lennarz, F. Golf, G. Magni, C. Di Guardo, A. S. Slutsky, C. Lim, B. Shaw, C. Duma, V. Pesudo, S. Gillespie, A. Devoto, E. Guetre, L. Camozzi, B. Bell, C. E. Dahl, M. Dossi, E. Alessi, M. MacDonald, A. J. Noble, F. Ardellier Desages, O. Davignon, B. Morrison, R. D. Fournier, Alberto Annovi, S. Kuula, Elvinia Riccobene, A. Rizzi, G. Hersak, J. Bagger, S. Brice, S. Khan, L. VanPagee, P. Salvo, R. Lubna, A. Bayo, M. Bouchard, J. Romualdez, G. Bianchi, H. Wang, S. Bicelli, T. A. Mohayai, A. Dal Molin, M. Breviario, C. Ienzi, M. Carlini, K. Hayashi, G. Monzani, G. A. Lukhanin, R. J. Ford, D. Yates, B. Velghe, G. Finocchiaro, C. Charette, M.H. Kushoro, E. Sansoucy, D. Reed, Pierre-Andre Amaudruz, A. Pocar, S. Scorza, M. Camozzi, T. Reilly, C. Crippa, S. Pordes, F. Padula, S. Westerdale, C. Straubel, P. Garcia Abia, A. Shi, D. Giorgi, A. Capra, S. Shawyer, S. Martin, F. Prelz, S. Back, D. Sablone, L. Takeuchi, D. Franco, L. Martin, An. Ianni, L. Tseng, P. McClurg, M. I. Martínez, D. Wood, A. Norrick, C. Pellegrino, J. Tseng, C. Ratti, M. Constable, V. Vedia, L. M. Tosatti, L. S. Giarratana, G. Fiorillo, M. Razeti, A. Patel, C. R. Natzke, S. Manni, M. Wada, S. Tacchino, M. Paterno, P. Gorel, P. Diaz Gomez Maqueo, N. Massacret, S. Cudmore, Marco Pallavicini, A. Heavey, Gabriele Croci, E. Kim, B. Celano, G. Batignani, E. Druszkiewicz, A. L. Renshaw, L. Giacomelli, D. Walter, S. Viel, Angelo Gargantini, D. Goeldi, P. Liimatainen, N. J. T. Smith, T. Schaubel, G. Cogliati, G. Foti, C. Mapelli, F. Retriere, Giuseppe Gorini, K. Patel, R. Tartaglia, N. Papini, M. Settimo, P. Pelliccione, P. Skensved, M. Leyton, V. Basile, A. Kittmer, G. D'Avenio, D. Rigamonti, R. Krücken, F. Guescini, F. Giacomini, E. Thomas, K. Hudson, Claudio Moretti, R. Santorelli, G. Hackman, R. Gobui, L. Viviani, C. Savarese, I. Kochanek, R. Migalla, J. Rode, F. Gabriele, D. Farina, F. Ferroni, F. Di Francesco, J. M. Calvo-Mozota, M. Suchenek, G. Hockin, J. Refsgaard, J. Kowalkowski, A. Pope, T. Lomonaco, S. King, Bhaskar Sur, C. L. Kendziora, M. Caravati, A. Ceccanti, W. Hawkins, W. Bonivento, C. Fernandes, G. Leblond, M. Mountaniol, A. B. McDonald, C. Accorsi, A. Stenzler, Federico Nati, V. Zambrano, D. Bishop, M. King, A. Sandoval, X. Li, P. Margetak, P. Agnes, J. L. Raaf, J. De Ruiter, Cristiano Galbiati, Giovanni Grosso, L. Lee, A. Ortiz de Solórzano, T. Hadden, T. Lindner, D. Biagini, L. Russel, C. Badia, Abba, A., Accorsi, C., Agnes, P., Alessi, E., Amaudruz, P., Annovi, A., Desages, F. A., Back, S., Badia, C., Bagger, J., Basile, V., Batignani, G., Bayo, A., Bell, B., Beschi, M., Biagini, D., Bianchi, G., Bicelli, S., Bishop, D., Boccali, T., Bombarda, A., Bonfanti, S., Bonivento, W. M., Bouchard, M., Breviario, M., Brice, S., Brown, R., Calvo-Mozota, J. M., Camozzi, L., Camozzi, M., Capra, A., Caravati, M., Carlini, M., Ceccanti, A., Celano, B., Cela Ruiz, J. M., Charette, C., Cogliati, G., Constable, M., Crippa, C., Croci, G., Cudmore, S., Dahl, C. E., Dal Molin, A., Daley, M., Di Guardo, C., D'Avenio, G., Davignon, O., Del Tutto, M., De Ruiter, J., Devoto, A., Diaz Gomez Maqueo, P., Di Francesco, F., Dossi, M., Druszkiewicz, E., Duma, C., Elliott, E., Farina, D., Fernandes, C., Ferroni, F., Finocchiaro, G., Fiorillo, G., Ford, R., Foti, G., Fournier, R. D., Franco, D., Fricbergs, C., Gabriele, F., Galbiati, C., Garcia Abia, P., Gargantini, A., Giacomelli, L., Giacomini, F., Giarratana, L. S., Gillespie, S., Giorgi, D., Girma, T., Gobui, R., Goeldi, D., Golf, F., Gorel, P., Gorini, G., Gramellini, E., Grosso, G., Guescini, F., Guetre, E., Hackman, G., Hadden, T., Hawkins, W., Hayashi, K., Heavey, A., Hersak, G., Hessey, N., Hockin, G., Hudson, K., Ianni, A., Ienzi, C., Ippolito, V., James, C. C., Jillings, C., Kendziora, C., Khan, S., Kim, E., King, M., King, S., Kittmer, A., Kochanek, I., Kowalkowski, J., Krucken, R., Kushoro, M., Kuula, S., Laclaustra, M., Leblond, G., Lee, L., Lennarz, A., Leyton, M., Li, X., Liimatainen, P., Lim, C., Lindner, T., Lomonaco, T., Lu, P., Lubna, R., Lukhanin, G. A., Luzon, G., Macdonald, M., Magni, G., Maharaj, R., Manni, S., Mapelli, C., Margetak, P., Martin, L., Martin, S., Martinez, M., Massacret, N., Mcclurg, P., Mcdonald, A. B., Meazzi, E., Migalla, R., Mohayai, T., Tosatti, L. M., Monzani, G., Moretti, C., Morrison, B., Mountaniol, M., Muraro, A., Napoli, P., Nati, F., Natzke, C. R., Noble, A. J., Norrick, A., Olchanski, K., Ortiz De Solorzano, A., Padula, F., Pallavicini, M., Palumbo, I., Panontin, E., Papini, N., Parmeggiano, L., Parmeggiano, S., Patel, K., Patel, A., Paterno, M., Pellegrino, C., Pelliccione, P., Pesudo, V., Pocar, A., Pope, A., Pordes, S., Prelz, F., Putignano, O., Raaf, J. L., Ratti, C., Razeti, M., Razeto, A., Reed, D., Refsgaard, J., Reilly, T., Renshaw, A., Retriere, F., Riccobene, E., Rigamonti, D., Rizzi, A., Rode, J., Romualdez, J., Russel, L., Sablone, D., Sala, S., Salomoni, D., Salvo, P., Sandoval, A., Sansoucy, E., Santorelli, R., Savarese, C., Scapparone, E., Schaubel, T., Scorza, S., Settimo, M., Shaw, B., Shawyer, S., Sher, A., Shi, A., Skensved, P., Slutsky, A., Smith, B., Smith, N. J. T., Stenzler, A., Straubel, C., Stringari, P., Suchenek, M., Sur, B., Tacchino, S., Takeuchi, L., Tardocchi, M., Tartaglia, R., Thomas, E., Trask, D., Tseng, J., Tseng, L., Vanpagee, L., Vedia, V., Velghe, B., Viel, S., Visioli, A., Viviani, L., Vonica, D., Wada, M., Walter, D., Wang, H., Wang, M. H. L. S., Westerdale, S., Wood, D., Yates, D., Yue, S., Zambrano, V., AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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), École des Mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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 (IMT Atlantique), Abba, A, Accorsi, C, Agnes, P, Alessi, E, Amaudruz, P, Annovi, A, Desages, F, Back, S, Badia, C, Bagger, J, Basile, V, Batignani, G, Bayo, A, Bell, B, Beschi, M, Biagini, D, Bianchi, G, Bicelli, S, Bishop, D, Boccali, T, Bombarda, A, Bonfanti, S, Bonivento, W, Bouchard, M, Breviario, M, Brice, S, Brown, R, Calvo-Mozota, J, Camozzi, L, Camozzi, M, Capra, A, Caravati, M, Carlini, M, Ceccanti, A, Celano, B, Cela Ruiz, J, Charette, C, Cogliati, G, Constable, M, Crippa, C, Croci, G, Cudmore, S, Dahl, C, Dal Molin, A, Daley, M, Di Guardo, C, D'Avenio, G, Davignon, O, Del Tutto, M, De Ruiter, J, Devoto, A, Diaz Gomez Maqueo, P, Di Francesco, F, Dossi, M, Druszkiewicz, E, Duma, C, Elliott, E, Farina, D, Fernandes, C, Ferroni, F, Finocchiaro, G, Fiorillo, G, Ford, R, Foti, G, Fournier, R, Franco, D, Fricbergs, C, Gabriele, F, Galbiati, C, Garcia Abia, P, Gargantini, A, Giacomelli, L, Giacomini, F, Giarratana, L, Gillespie, S, Giorgi, D, Girma, T, Gobui, R, Goeldi, D, Golf, F, Gorel, P, Gorini, G, Gramellini, E, Grosso, G, Guescini, F, Guetre, E, Hackman, G, Hadden, T, Hawkins, W, Hayashi, K, Heavey, A, Hersak, G, Hessey, N, Hockin, G, Hudson, K, Ianni, A, Ienzi, C, Ippolito, V, James, C, Jillings, C, Kendziora, C, Khan, S, Kim, E, King, M, King, S, Kittmer, A, Kochanek, I, Kowalkowski, J, Krucken, R, Kushoro, M, Kuula, S, Laclaustra, M, Leblond, G, Lee, L, Lennarz, A, Leyton, M, Li, X, Liimatainen, P, Lim, C, Lindner, T, Lomonaco, T, Lu, P, Lubna, R, Lukhanin, G, Luzon, G, Macdonald, M, Magni, G, Maharaj, R, Manni, S, Mapelli, C, Margetak, P, Martin, L, Martin, S, Martinez, M, Massacret, N, Mcclurg, P, Mcdonald, A, Meazzi, E, Migalla, R, Mohayai, T, Tosatti, L, Monzani, G, Moretti, C, Morrison, B, Mountaniol, M, Muraro, A, Napoli, P, Nati, F, Natzke, C, Noble, A, Norrick, A, Olchanski, K, Ortiz De Solorzano, A, Padula, F, Pallavicini, M, Palumbo, I, Panontin, E, Papini, N, Parmeggiano, L, Parmeggiano, S, Patel, K, Patel, A, Paterno, M, Pellegrino, C, Pelliccione, P, Pesudo, V, Pocar, A, Pope, A, Pordes, S, Prelz, F, Putignano, O, Raaf, J, Ratti, C, Razeti, M, Razeto, A, Reed, D, Refsgaard, J, Reilly, T, Renshaw, A, Retriere, F, Riccobene, E, Rigamonti, D, Rizzi, A, Rode, J, Romualdez, J, Russel, L, Sablone, D, Sala, S, Salomoni, D, Salvo, P, Sandoval, A, Sansoucy, E, Santorelli, R, Savarese, C, Scapparone, E, Schaubel, T, Scorza, S, Settimo, M, Shaw, B, Shawyer, S, Sher, A, Shi, A, Skensved, P, Slutsky, A, Smith, B, Smith, N, Stenzler, A, Straubel, C, Stringari, P, Suchenek, M, Sur, B, Tacchino, S, Takeuchi, L, Tardocchi, M, Tartaglia, R, Thomas, E, Trask, D, Tseng, J, Tseng, L, Vanpagee, L, Vedia, V, Velghe, B, Viel, S, Visioli, A, Viviani, L, Vonica, D, Wada, M, Walter, D, Wang, H, Wang, M, Westerdale, S, Wood, D, Yates, D, Yue, S, and Zambrano, V

Subjects
ventilator, Emergency Use Authorization, Coronavirus disease 2019 (COVID-19), Fault conditions, Computational Mechanics, Certification, 01 natural sciences, 010305 fluids & plasmas, law.invention, Mechanical parts, Food and drug administration, Compressed oxygen, Food and Drug Administration, Health care professionals, Industrial partners, Intensive therapy, Ventilation mode, Mechanical ventilator, law, 0103 physical sciences, Pandemic, medicine, 010306 general physics, Fluid Flow and Transfer Processes, Physics, [PHYS]Physics [physics], Mechanical Engineering, healthcare, Articles, Condensed Matter Physics, medicine.disease, 3. Good health, Medical gas supply, Mechanical Ventilation, COVID-19 Pandemic, covid-19, Mechanics of Materials, Others, Ventilation (architecture), Medical emergency, Settore ING-INF/05 - Sistemi di Elaborazione delle Informazioni, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world

Published
2021

18. Prompt and delayed γ spectroscopy of neutron-rich Kr94 and observation of a new isomer

Author

R. Chakma, N. Cieplicka-Oryńczak, P. Adsley, G. Tocabens, Muriel Fallot, K. Belvedere, D. Gjestvang, L. Qi, J. Wiederhold, S. Leoni, C. Sürder, J. Benito, J. N. Wilson, K. Hauschild, R. B. Gerst, Stephan Oberstedt, Ł. W. Iskra, C. Porzio, P. A. Söderström, G. Häfner, M. Rudigier, I. Matea, C. Henrich, D. Verney, R.L. Canavan, K. Miernik, V. Vedia, D. Ralet, J. Nemer, P. Koseoglou, M. Piersa, N. Warr, R. Lozeva, L. Le Meur, A. Algora, M. Lebois, N. Jovančević, K. Rezynkina, S. Jazrawi, A. Blazhev, S. Courtin, M. Bunce, S. Bottoni, P. H. Regan, A. Boso, A. Lopez-Martens, C. Schmitt, B. Fornal, P. Ivanov, B. Wasilewska, L. M. Fraile, F. Ibrahim, M. Babo, T. Kurtukian-Nieto, A. Gottardo, G. Benzoni, T. Kröll, D. Reygadas-Tello, E. Adamska, J. Ljungvall, V. Guadilla, A. Korgul, Y. Popovitch, W. Paulsen, I. Homm, D. Thisse, M. L. Cortés, M. Heine, Fabio Zeiser, C. Delafosse, V. Sánchez-Tembleque, P. Davies, M. Yavachova, S. Ziliani, and D. Etasse

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Yrast, Nuclear Theory, 01 natural sciences, 7. Clean energy, Atomic orbital, Nuclear fission, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Spectroscopy
Abstract

Prompt and delayed γ -ray spectroscopy of the neutron-rich 94 Kr was performed, as part of the fission campaign at the ALTO facility of the IPN Orsay, using the fast-neutron-induced fission reaction 238 U ( n , f ) in combination with the ν -Ball array, a novel hybrid γ spectrometer for energy and lifetime measurements. Several new yrast and nonyrast transitions were observed for the first time, extending the previously known level scheme. Additionally, we report on the observation of a new short-lived isomer at 3444 keV with a half-life of 32(3) ns. The analysis of the Nilsson orbitals obtained from Gogny cranked Hartree-Fock-Bogoliubov calculations suggests a ( 9 − ) spin and an oblate deformation for this isomer corresponding to a two-quasineutron state, indicating an isomeric structure very similar to that of the neighboring isotones 96 Sr and 92 Se

Published
2020

19. Competition between Allowed and First-Forbidden β Decay: The Case of Hg208→Tl208

Author

V. F. E. Pucknell, R.-B. Gerst, M. Lund, I.H. Lazarus, P. H. Regan, N. Marginean, R. Shearman, J. Phrompao, M. Piersa, V. Vedia, Miguel Madurga, R. Lica, Marc Huyse, F. Wearing, J. Kurcewicz, J. R. Creswell, María José García Borge, R. Mărginean, L. M. Fraile, W. Gelletly, S. Pascu, István Kuti, S. Stegemann, T. Alexander, A. Negret, C. R. Nita, Paul Greenlees, C. Mihai, Raymond J. Carroll, Andrei Andreyev, F. Rotaru, Ángel Perea, R. D. Page, P. M. Walker, M. Brunet, Zs. Podolyák, I. Marroquin, R. Wadsworth, D. S. Judson, A. Gredley, P. Van Duppen, E. Rapisarda, M. Rudigier, H. De Witte, Zena Patel, T. Berry, Enrique Nácher, H. Grawe, M. Górska, N. Warr, L. J. Harkness-Brennan, S. Lalkovski, S. M. Judge, P. Rahkila, Joonas Konki, S. Ansari, Thierry Stora, C. M. Shand, R. E. Mihai, E. R. Gamba, Claes Fahlander, H. O. U. Fynbo, Olof Tengblad, and C. Sotty

Subjects
Physics, Nuclear Theory, General Physics and Astronomy, Parity (physics), 01 natural sciences, 7. Clean energy, Neutron capture, medicine.anatomical_structure, Nucleosynthesis, Excited state, 0103 physical sciences, medicine, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus, Fermi Gamma-ray Space Telescope
Abstract

The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z

Published
2020

20. Octupole states in Tl207 studied through β decay

Author

István Kuti, A. Turturica, Claes Fahlander, F. Rotaru, Ángel Perea, P. Van Duppen, I. Lazarus, Joonas Konki, H. Grawe, M. Górska, S. Pascu, A. Negret, Raymond J. Carroll, Zs. Podolyák, S. Stegemann, B. A. Brown, J. Phrompao, Miguel Madurga, F. Wearing, D. S. Judson, R. Mărginean, M. Rudigier, P. Greenlees, M. Lund, T. Alexander, S. Lalkovski, H. O. U. Fynbo, Olof Tengblad, S. Ansari, R. Shearman, Natalia Timofeyuk, R.-B. Gerst, V. Vedia, Marc Huyse, E. Rapisarda, J. Kurcewicz, H. De Witte, C. Mihai, M. Brunet, P. M. Walker, P. H. Regan, Edward Simpson, R. Lica, J. R. Cresswell, E.R. Gamba, T. Berry, Enrique Nácher, N. Warr, C. Niţă, Magda Kowalska, A. Gredley, Thierry Stora, A. N. Andreyev, S. M. Judge, L. J. Harkness-Brennan, María José García Borge, C. M. Shand, W. Gelletly, R. D. Page, P. Rahkila, N. Marginean, C. Sotty, Zena Patel, R. E. Mihai, M. Piersa, S. Nae, L. M. Fraile, V. Pucknell, and I. Marroquin

Subjects
Physics, Coupling, 010308 nuclear & particles physics, SHELL model, State (functional analysis), 01 natural sciences, Atomic orbital, 0103 physical sciences, Atomic physics, 010306 general physics, 10. No inequality, Nucleon, Spectroscopy, Mixing (physics)
Abstract

The β decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through γ-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the πs−11/2, πd−13/2, and πh−111/2 shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s1/2-coupled) are identified and three more states (d3/2-coupled) are tentatively assigned using spin-parity inferences, while further h11/2-coupled states may also have been observed for the first time. Comparisons are made with state-of-the-art large-scale shell model calculations and previous observations made in this region, and systematic underestimation of the energy of the octupole vibrational states is noted. We suggest that in order to resolve the difference in predicted energies for collective and noncollective t=1 states (t is the number of nucleons breaking the 208Pb core), the effect of t=2 mixing may be reduced for octupole-coupled states. The inclusion of mixing with t=0,2,3 excitations is necessary to replicate all t=1 state energies accurately.

Published
2020

21. Search for beta-delayed proton emission from 11 Be

Author

M. V. Lund, Johannes Lachner, Silke Merchel, E. Nacher, V. Vedia, Thomas Nilsson, Miguel Madurga, Olof Tengblad, M. Carmona-Gallardo, J. A. Briz, H. O. U. Fynbo, A. Garzon Camacho, K. Riisager, Peter Steier, María José García Borge, O. Forstner, J. G. Johansen, Björn Jonson, L. M. Fraile, European Commission, Ministerio de Economía y Competitividad (España), and Danish Council for Independent Research

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, 010308 nuclear & particles physics, Branching fraction, FOS: Physical sciences, nucl-ex, 7. Clean energy, 01 natural sciences, Ion source, Ion, Nuclear physics, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, 0103 physical sciences, Nuclear Physics - Experiment, Física nuclear, Proton emission, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Accelerator mass spectrometry
Abstract

8 pags., 4 figs., 4 tabs., We report on an attempt to reproduce the observation of β-delayed proton emission from Be through detection of the final state nucleus Be with accelerator mass spectrometry. Twelve samples were collected at the ISOLDE facility at CERN at different separator settings, allowing tests of different sources of contamination to be carried out. The observed amounts of Be per collected Be rule out several contamination sources, but do not agree internally. Formation of BeH molecular ions in the ion source may explain our data, in which case an upper limit of the βp branching ratio of 2.2 × 10 can be derived., We would like to acknowledge support from the European Union’s Horizon 2020 research and innovation programme under Grant agreement no. 654002, from the Spanish research projects FPA2015-64969- P, FPA2015-65035-P and FPA2017-87568-P (MINECO/FEDER, UE), and from the Danish Council for Independent Research (DFF-4181- 00218).

Published
2020

22. Half-life measurements in Dy164,166 using γ−γ fast-timing spectroscopy with the ν -Ball spectrometer

Author

K. Hadynska-Klek, S. Bottoni, Stephan Oberstedt, D. T. Doherty, P. A. Söderström, D. Thisse, R. Shearman, V. Sánchez-Tembleque, V. Vedia, V. Karayonchev, S. Courtin, Zs. Podolyák, Giuseppe Lorusso, J. N. Wilson, G. Häfner, M. Rudigier, C. R. Niţă, M. Lebois, Mohammad Nakhostin, M. Brunet, L. M. Fraile, W. Witt, A. R. L. Kennington, L. Qi, Gavin Lotay, N. Jovancevic, R.L. Canavan, N. Cieplicka-Oryńczak, Ł. W. Iskra, Sean Collins, P. H. Regan, J.-M. Régis, M. Heine, J. Benito, and P. Koseoglou

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Yrast, Nuclear Theory, Gamma ray, Nuclear structure, Coulomb excitation, 01 natural sciences, Excited state, 0103 physical sciences, Quadrupole, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

We report on the measurement of lifetimes of excited states in the near-mid-shell nuclei Dy164,166 using the gamma-ray coincidence fast-timing method. The nuclei of interest were populated using reactions between an O18 beam and a gold-backed isotopically enriched Dy164 target of thickness 6.3mg/cm2 at primary beam energies of 71, 76, and 80 MeV from the IPN-Orsay laboratory, France. Excited states were populated in Dy164, Dy166, and W178,179 following Coulomb excitation, inelastic nuclear scattering, two-neutron transfer, and fusion-evaporation reaction channels respectively. Gamma rays from excited states were measured using the ν-Ball high-purity germanium (HPGe)-LaBr3 hybrid γ-ray spectrometer with the excited state lifetimes extracted using the fast-timing coincidence method using HPGe-gated LaBr3-LaBr3 triple coincident events. The lifetime of the first Iπ=2+ excited state in Dy166 was used to determine the transition quadrupole deformation of this neutron-rich nucleus for the first time. The experimental methodology was validated by showing consistency with previously determined excited state lifetimes in Dy164. The half-lives of the yrast 2+ states in Dy164 and Dy166 were 2.35(6) and 2.3(2) ns, respectively, corresponding to transition quadrupole moment values of Q0=7.58(9) and 7.5(4) eb, respectively. The lifetime of the yrast 2+ state in Dy166 is consistent with a quenching of nuclear quadrupole deformation at β≈0.35 as the N=104 mid-shell is approached.

Published
2020

23. Disentangling decaying isomers and searching for signatures of collective excitations in β decay

Author

José Antonio Briz, Dmitry Gorelov, Jani Hakala, Juha Äystö, V. Vedia, Sami Rinta-Antila, Heikki Penttilä, E. Ganioǧlu, Iain Moore, W. Gelletly, M. Lebois, Anu Kankainen, S. E. A. Orrigo, Muriel Fallot, Jorge Agramunt, Tommi Eronen, A. Cucoanes, Jukka Koponen, M. Monserrate, Enrique Nácher, J. L. Tain, M. Estienne, D. Jordan, Amanda Porta, J. N. Wilson, E. Valencia, B. Rubio, Annika Voss, T. Shiba, A. A. Sonzogni, L. M. Fraile, Volker Sonnenschein, T. Martinez, A.-A. Zakari-Issoufou, V. Kolhinen, Ari Jokinen, L. Le Meur, A. Algora, Juuso Reinikainen, Ilkka Pohjalainen, K. Rytkönen, A. Montaner-Pizá, M. Reponen, V. Guadilla, Centre National de la Recherche Scientifique (France), Ministerio de Economía y Competitividad (España), European Commission, Consejo Superior de Investigaciones Científicas (España), 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
Neutron-rich nuclei, History, Isotope-separator-on-line, Ground state, Penning trap, spektroskopia, Beta decay, 01 natural sciences, Education, Nuclear physics, 0103 physical sciences, Gamma-ray spectroscopy, 010306 general physics, Nuclear Experiment, Physics, Pygmy dipole resonances, 010308 nuclear & particles physics, Gamma rays, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], 3. Good health, Computer Science Applications, Quasiparticle, Isomeric state, Física nuclear, ydinfysiikka, Gamma ray spectrometers, Collective excitations
Abstract

6 pags., 3 figs., 1 tab. -- 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK, In this contribution we summarize the recent study of the β decay of neutron-rich nuclei with isomeric states close in energy to the ground states. The disentanglement of each pair of β-decaying states was achieved by applying different strategies and using the purification capabilities of the JYFLTRAP double Penning trap system at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. The Total Absorption γ-ray Spectroscopy technique was employed to determine the β intensity probabilities populating the excited states in the daughter nuclei. Previously undetected β intensity was found and we have already evaluated the impact of part of these results on reactor summation calculations. The possibility to populate states associated with the Pygmy Dipole Resonance in the β decay of 96gsY has also been investigated thanks to the sensitivity of our technique to high-lying strength in the daughter nuclei., This work has been supported by the CNRS challenge NEEDS and the associated NACRE project, as well as by the Spanish Ministerio de Econom´ıa y Competitividad under Grants No. FPA2011-24553, No. AIC-A-2011-0696, No. FPA2014-52823-C2-1-P, No. FPA2015-65035-P, No. FPI/BES-2014-068222, No. FPA2017-83946-C2-1-P and the program Severo Ochoa (SEV-2014-0398), by the Spanish Ministerio de Educacion under the FPU12/01527 Grant, by the European Commission under the FP7/EURATOM contract 605203 and the FP7/ENSAR contract 262010, and by the Junta para la Ampliacion de Estudios ´ Programme (CSIC JAE-Doc contract) co-financed by ESF.

Published
2020

24. Determination of β -decay ground state feeding of nuclei of importance for reactor applications

Author

V. Vedia, Sami Rinta-Antila, Volker Sonnenschein, D. Jordan, T. Martinez, Muriel Fallot, V. Guadilla, W. Gelletly, Amanda Porta, A. A. Sonzogni, Dmitry Gorelov, L. M. Fraile, A. Montaner-Pizá, Ari Jokinen, L. Le Meur, José Antonio Briz, Juha Äystö, T. Shiba, A. Cucoanes, A.-A. Zakari-Issoufou, K. Rytkönen, Jukka Koponen, Heikki Penttilä, Iain Moore, Anu Kankainen, S. E. A. Orrigo, Enrique Nácher, Veli Kolhinen, Annika Voss, Ilkka Pohjalainen, Tommi Eronen, E. Valencia, Berta Rubio, Jani Hakala, M. Lebois, Juuso Reinikainen, J. N. Wilson, M. Reponen, M. Monserrate, E. Ganioglu, M. Estienne, Jorge Agramunt, J. L. Tain, Alejandro Algora, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), Science and Technology Facilities Council (UK), 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, Work (thermodynamics), Fission products, 010308 nuclear & particles physics, Nuclear structure, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 7. Clean energy, 01 natural sciences, Synthetic data, Nuclear physics, 13. Climate action, Robustness (computer science), 0103 physical sciences, Neutron, High Energy Physics::Experiment, Decay heat, Nuclear Experiment (nucl-ex), 010306 general physics, Ground state, Nuclear Experiment
Abstract

12 pags., 6 figs., 3 tabs., In β-decay studies the determination of the decay probability to the ground state (g.s.) of the daughter nucleus often suffers from large systematic errors. The difficulty of the measurement is related to the absence of associated delayed γ -ray emission. In this work we revisit the 4π γ − β method proposed by Greenwood and collaborators in the 1990s, which has the potential to overcome some of the experimental difficulties. Our interest is driven by the need to determine accurately the β-intensity distributions of fission products that contribute significantly to the reactor decay heat and to the antineutrinos emitted by reactors. A number of such decays have large g.s. branches. The method is relevant for nuclear structure studies as well. Pertinent formulas are revised and extended to the special case of β-delayed neutron emitters, and the robustness of the method is demonstrated with synthetic data. We apply it to a number of measured decays that serve as test cases and discuss the features of the method. Finally, we obtain g.s. feeding intensities with reduced uncertainty for four relevant decays that will allow future improvements in antineutrino spectrum and decay heat calculations using the summation method., This work has been supported by the Spanish Ministerio de Economía y Competitividad under Grants No. FPA2011- 24553, No. AIC-A-2011-0696, No. FPA2014-52823-C2- 1-P, No. FPA2015-65035-P, No. FPI/BES-2014-068222, No. FPA2017-83946-C2-1-P, and No. RTI2018-098868-BI00 and the program Severo Ochoa (SEV-2014-0398); by the Spanish Ministerio de Educación under Grant No. FPU12/01527; by the Spanish Ministerio de Ciencia e Innovación under Grant No. PID2019-104714GB-C21; by the European Commission under CHANDA project funded under FP7-EURATOM-FISSION Grant No. 605203; the FP7/ENSAR Contract No. 262010; the SANDA project funded under H2020-EURATOM-1.1 Grant No. 847552; the Horizon 2020 research and innovation programme under Grant No. 771036 (ERC CoG MAIDEN); by the Generalitat Valenciana regional funds PROMETEO/2019/007/; and by the Junta para la Ampliacion de Estudios ´ Programme (CSIC JAE-Doc contract) co-financed by ESF. We acknowledge the support of the UK Science and Technology Facilities Council (STFC) Grant No. ST/P005314/1; of the Polish National Agency for Academic Exchange (NAWA) under Grant No. PPN/ULM/2019/1/00220; and of the National Science Center, Poland, under Contract No. 2019/35/D/ST2/02081. This work was also supported by the Academy of Finland under the Finnish Centre of Excellence Programme (Project No. 213503, Nuclear and Accelerator-Based Physics Research at JYFL). A.K. and T.E. acknowledge support from the Academy of Finland under Projects No. 275389 and No. 295207, respectively. This work has also been supported by the CNRS challenge NEEDS and the associated NACRE project, the CNRS/in2p3 PICS TAGS between Subatech and IFIC, and the CNRS/in2p3 Master projects Jyvaskyla and OPALE.

Published
2020

25. Study of exotic decay of Cs isotope close to the proton drip line

Author

R. Wadsworth, Thierry Stora, Ushasi Dattaf, Panu Rahkila, Miguel Madurga, S. Chakraborty, A Becerril, F. Rotaru, E. Rapisarda, Ángel Perea, Olof Tengblad, S. Pascu, P Bhattacharya, L. M. Fraile, V. F. E. Pucknell, L. J. Harkness-Brennan, S. K. Mandal, P. Das, A. Bhattacharyya, I.H. Lazarus, Robert Page, R. Mărginean, A. Rahman, N. Marginean, Enrique Nácher, N. Warr, Andrei Andreyev, V. Vedia, Joonas Konki, J. Ray, Marc Huyse, Paul Greenlees, D. S. Judson, A. Gottberg, Joakim Cederkäll, Cosmin Teodor Mihai, I. Morroquin, H. De Witte, Magda Kowalska, R. Lica, María José García Borge, J. Kurcewicz, C. Sotty, A. Negret, P. Van Duppen, Science and Engineering Research Board (India), Department of Atomic Energy (India), European Commission, Ministerio de Economía y Competitividad (España), and Council for Scientific and Industrial Research (India)

Subjects
History, Proton, Ground state, Particle emissions, Nuclear Theory, Exotic decay, Proton spectra, Spallation reactions, Cesium, 01 natural sciences, Lanthanum compounds, Education, Nuclear physics, Particle emission, Germanium compounds, Gamma detectors, 0103 physical sciences, Nuclear Physics - Experiment, Spallation, 010306 general physics, Nuclear Experiment, Line (formation), Physics, Large Hadron Collider, Isotope, 010308 nuclear & particles physics, Charged particle arrays, Charged particle, Computer Science Applications, Physics::Accelerator Physics, Time distribution, Física nuclear, Unbound state, ydinfysiikka
Abstract

6 pags., 6 figs. -- 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK, The neutron-deficient 115Cs was produced at ISOLDE, CERN by spallation reaction using 1.4 GeV proton on LaC2 target. The exotic decay modes were studied by using a charged particle array (DSSD and pad detectors) and a ¿-detector array (four Clovers) at the ISOLDE decay station (IDS). In this report, results on observed ß-delayed particle emission from 115Cs, a nucleus close to proton drip line, is presented. By measuring the time distribution in the delayed proton spectrum, the half-life of the ground state of 115Cs was extracted. The obtained half-life is in agreement with previous reported value. For the first time, the p-unbound states of 115Xe, obtained by measuring beta-delayed protons from 115Cs is reported., Ushasi Datta acknowledges with thanks to SERB, India for the financial support (travel) for attending and presenting the paper in the conference (INPC2019). Authors of SINP deeply acknowledge the SEND (XI th plan, DAE, India) and IENP/HENPP (XII th plan, DAE, India) project grant. This project has received funding from the European Union’s Horizon 2020 ENSAR2 project under grant agreement no 654002 and the Spanish research council under contract FPA2015-64969-P. The authors (P.Das and A.Bhattacharyya) acknowledge with thanks the financial support provided by the CSIR vide file number 09/489(0111)/2019EMR-I and 09/489(0115)/2019EMR-I respectively.

Published
2020

26. Multi-quasiparticle sub-nanosecond isomers in $^{178}$W

Author

M. Lebois, R. Shearman, M. Brunet, L. Qi, Gavin Lotay, V. Vedia, V. Sánchez-Tembleque, J.-M. Régis, M. Heine, S. Courtin, R. Canavan, Mohammad Nakhostin, Giuseppe Lorusso, D. T. Doherty, Ł. W. Iskra, J. N. Wilson, C. R. Nita, S. Bottoni, V. Karayonchev, N. Cieplicka-Oryńczak, A. R. L. Kennington, Zs. Podolyák, J. Jolie, J. Benito, P. H. Regan, P. Koseoglou, A. Blazhev, P. A. Söderström, L. M. Fraile, P. M. Walker, Stephan Oberstedt, W. Witt, K. O. Zell, N. Jovancevic, K. Hadynska-Klek, M. Rudigier, Institut de Physique Nucléaire d'Orsay (IPNO), 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), Université Paris-Sud - Paris 11 (UP11), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Detector, Aucun, Calorimetry, Scintillator, Nanosecond, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, lcsh:QC1-999, 3. Good health, 0103 physical sciences, Quasiparticle, ddc:530, Física nuclear, Atomic physics, 010306 general physics, Spectroscopy, lcsh:Physics, Beam (structure), Mixing (physics)
Abstract

We report on the first measurement of the half-lives of K-pi = 11(-) and 12(+) four-quasiparticle states in the even-even nucleus W-178. The sub-nanosecond half-lives were measured by applying the centroid shift method to data taken with LaBr3(Ce) scintillator detectors of the NuBall array at the ALTO facility in Orsay, France. The half-lives of these states only became experimentally accessible by the combination of several experimental techniques - scintillator fast timing, isomer spectroscopy with a pulsed beam, and the event-by-event calorimetry information provided by the NuBall array. The measured half-lives are 476(44)ps and 275(65)ps for the I-pi = 11(-) and 12(+) states, respectively. The decay transitions include weakly hindered E1 and E2 branches directly to the ground-state band, bypassing the two-quasiparticle states. This is the first such observation for an E1 transition. The interpretation of the small hindrance hinges on mixing between the ground-state band and the t-band. (C) 2019 The Author(s). Published by Elsevier B.V.

Published
2020

27. Performance evaluation of novel LaBr 3 (Ce) scintillator geometries for fast-timing applications

Author

Henryk Mach, M. Carmona-Gallardo, J. M. Udías, L. M. Fraile, and V. Vedia

Subjects
Physics, Nuclear and High Energy Physics, Scintillation, Photomultiplier, 010308 nuclear & particles physics, business.industry, Monte Carlo method, Detector, Constant fraction discriminator, Scintillator, Atomic packing factor, 01 natural sciences, Optics, 0103 physical sciences, Calibration, 010306 general physics, business, Instrumentation
Abstract

We evaluate the performance of two LaBr 3 (Ce) crystals that were produced with special geometries, aimed at enhancing the scintillation light collection and thus the time resolution. Their design was motivated by the construction of high-performance fast-timing arrays like the FAst TIMing array for DESPEC (FATIMA), which demands a high packing factor in addition to good time and energy resolutions. Energy resolution and efficiency were measured using standard calibration sources. Timing measurements were performed at 60 Co and 22 Na γ -energies against a fast BaF 2 reference detector. The time resolution was optimized by the choice of the photomultiplier bias voltage and the fine tuning of the constant fraction discriminator parameters. Monte Carlo simulations using the Geant4 toolkit were performed in order to achieve a better understanding of how the new geometries affect the light transport and thus the performance of the crystals. It is found that the conical-shaped LaBr 3 (Ce) crystals are optimal for fast-timing applications and for the construction of arrays such as FATIMA.

Published
2017

28. Fast-timing measurements in the ground-state band of Pd114

Author

T. Lauritsen, T. Kröll, L. A. Gurgi, F. G. Kondev, G. J. Lane, I. Burrows, D. M. Cullen, O. Yordanov, S. Lalkovski, Alison Bruce, John P. Greene, T. Daniel, V. F. E. Pucknell, D. Seweryniak, D. J. Hartley, Gavin Lotay, C. M. Shand, M. Smolen, T. Berry, S. Bottoni, C. R. Niţă, E. A. Stefanova, J. Sethi, E.R. Gamba, R. Ilieva, M. Carmona Gallardo, S. Zhu, J. Rohrer, J. T. Anderson, A. D. Ayangeakaa, S. Ilieva, J. Simpson, Matthew Reed, M. P. Carpenter, P. Copp, M. Rudigier, V. Vedia, I.H. Lazarus, P. H. Regan, Raymond J. Carroll, Zs. Podolyák, and G. Fernández Martínez

Subjects
Physics, Work (thermodynamics), Isotope, Yrast, chemistry.chemical_element, medicine.anatomical_structure, chemistry, medicine, Gammasphere, Interacting boson model, Atomic physics, Ground state, Nucleus, Palladium
Abstract

Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in ¹¹⁴Pd populated via ²⁵²Cf decay, have been measured. The measured lifetimes are τ₂+=103(10)ps, τ₄+=22(13)ps, and τ₆+≤10ps for the 2⁺₁, 4⁺₁, and 6⁺₁ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2;J→J−2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E₂)=B(E2;4⁺₁→2⁺₁)/B(E2;2⁺₁→0⁺₁)=0.80(42) is measured for the first time in ¹¹⁴Pd and compared with the known values RB(E₂) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs.

Published
2019

29. Total absorption γ -ray spectroscopy of the β -delayed neutron emitters I137 and Rb95

Author

T. Shiba, W. Gelletly, A. Cucoanes, Jukka Koponen, Enrique Nácher, L. M. Fraile, V. Guadilla, K. Rytkönen, Jorge Agramunt, Muriel Fallot, J. N. Wilson, T. Martinez, A. A. Sonzogni, Annika Voss, J. L. Tain, M. Reponen, Ari Jokinen, A. Montaner-Pizá, L. Le Meur, A. Algora, Juha Äystö, José Antonio Briz, M. Lebois, Dmitry Gorelov, A.-A. Zakari-Issoufou, Ilkka Pohjalainen, B. Rubio, M. Monserrate, Jani Hakala, Heikki Penttilä, Iain Moore, Anu Kankainen, S. E. A. Orrigo, E. Valencia, V. Vedia, Veli Kolhinen, Sami Rinta-Antila, Amanda Porta, T. Eronen, E. Ganioglu, M. Estienne, Juuso Reinikainen, Volker Sonnenschein, and D. Jordan

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, Penning trap, 01 natural sciences, Nuclear physics, 13. Climate action, 0103 physical sciences, Neutron, Gamma spectroscopy, Nuclear Experiment, 010306 general physics, Spectroscopy, Absorption (electromagnetic radiation), Delayed neutron
Abstract

The decays of the β-delayed neutron emitters I137 and Rb95 have been studied with the total absorption γ-ray spectroscopy technique. The purity of the beams provided by the JYFLTRAP Penning trap at the ion guide isotope separator on-line facility in Jyvaskyla allowed us to carry out a campaign of isotopically pure measurements with the decay total absorption γ-ray spectrometer, a segmented detector composed of 18 NaI(Tl) modules. The contamination coming from the interaction of neutrons with the spectrometer has been carefully studied, and we have tested the use of time differences between prompt γ rays and delayed neutron interactions to eliminate this source of contamination. Due to the sensitivity of our spectrometer, we have found a significant amount of β intensity to states above the neutron separation energy that deexcite by γ rays, comparable to the neutron emission probability. The competition between γ deexcitation and neutron emission has been compared with Hauser-Feshbach calculations, and it can be understood as a nuclear structure effect. In addition, we have studied the impact of the β-intensity distributions determined in this work on reactor decay heat and reactor antineutrino spectrum summation calculations. The robustness of our results is demonstrated by a thorough study of uncertainties and with the reproduction of the spectra of the individual modules and the module-multiplicity gated spectra. This work represents the state-of-the-art of our analysis methodology for segmented total absorption spectrometers.

Published
2019

30. $\gamma$-ray Spectroscopy of $^{85}$Se Produced in $^{232}$Th Fission

Author

I. Homm, M. Ciemała, Stephan Oberstedt, K. Rezynkina, P. A. Söderström, B. Fornal, A. Lopez-Martens, M. Bunce, V. Vedia, D. Verney, J. N. Wilson, J. Nemer, B. Wasilewska, A. Algora, M. Babo, R. B. Gerst, L. M. Fraile, Y. Popovitch, R. Chakma, T. Kurtukian-Nieto, Ł. W. Iskra, W. Paulsen, E. Adamska, D. Ralet, G. Häfner, M. Piersa, G. Benzoni, M. Rudigier, A. Fijałkowska, A. Blazhev, S. Leoni, D. Reygadas Tello, K. Hauschild, P. H. Regan, M. S. Yavahchova, J. Wiederhold, V. Guadilla, N. Warr, C. Delafosse, C. Schmitt, R.L. Canavan, V. Sánchez-Tembleque, K. Miernik, R. Lozeva, I. Matea, P. Davies, Muriel Fallot, N. Jovančević, S. Bottoni, M. Lebois, N. Cieplicka-Oryńczak, P. Adsley, C. Henrich, G. Tocabens, K. Belvedere, D. Gjestvang, T. Kröll, L. Cortes, C. Sürder, L. Qi, S. M. Collins, D. Etasse, M. Heine, Fabio Zeiser, A. Boso, F. Ibrahim, J. Benito, A. Korgul, J. Ljungvall, D. Thisse, L. Le-meur, A. Gottardo, P. Koseoglou, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), 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 Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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 (IMT Atlantique), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, Fission, Yrast, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Aucun, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Excited state, 0103 physical sciences, Neutron source, Gamma spectroscopy, Nuclear Experiment
Abstract

International audience; Excited states in the neutron-rich 85Se nucleus have been studied using for the first time a fast neutron-induced fission of 232Th. The experiment was performed at the ALTO facility of the IPN Orsay. Coupling of the LICORNE directional neutron source with the ν-ball high-resolution γ-ray spectrometer provided unique access to high-spin states in neutron-rich fission fragments from the 232Th(n, f) reaction. A preliminary level scheme of 85Se was established by the analysis of prompt γ–γ–γ coincidences. Identification of the all known yrast states in 85Se is the first step towards studies of more neutron-rich Se isotopes.

Published
2019

31. β decay of In133 : γ emission from neutron-unbound states in Sn133

Author

Robert Grzywacz, B. A. Marsh, J. G. Correia, M. Fila, L. M. Fraile, D. V. Fedorov, C. Costache, R. Lica, K. Chrysalidis, J. M. Udías, L. J. Harkness-Brennan, A. Turturica, S. Pascu, William B. Walters, Z. Janas, S. Viñals, S. Paulaskalas, Miguel Madurga, B. Olaizola, J. Benito, G. S. Simpson, A. Villa, R. Mărginean, V. N. Fedosseev, Henryk Mach, J. Kurcewicz, K. Miernik, V. F. E. Pucknell, C. Henrich, Joonas Konki, L. Stan, C. Mazzocchi, F. Rotaru, Ángel Perea, J.-M. Régis, C. Sotty, M. Kicińska-Habior, Robert Page, T. Day Goodacre, M. Carmona, A. Fijałkowska, E. Rapisarda, María José García Borge, A. E. Barzakh, R. Álvarez-Rodríguez, Sebastian Rothe, J. G. Cubiss, Paul Greenlees, C. Mihai, A. Illana, A. N. Andreyev, P. Rahkila, V. Vedia, A. Korgul, Marc Huyse, V. Sánchez-Tembleque, D. Galaviz, M. Stryjczyk, M. C. Martínez, H. De Witte, E. Adamska, I.H. Lazarus, N. Marginean, T. Berry, A. Negret, G. Fernández-Martínez, Enrique Nácher, N. Warr, H. O. U. Fynbo, Olof Tengblad, G. Benzoni, Karl Johnston, P. Van Duppen, M. Stanoiu, D. S. Judson, I. Marroquín, R. Wadsworth, V. Karanyonchev, and M. Piersa

Subjects
Physics, Spin states, 010308 nuclear & particles physics, Gamma ray, 01 natural sciences, 7. Clean energy, Beta decay, Ion source, 3. Good health, Ionization, Excited state, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Ground state
Abstract

Excited states in Sn-133 were investigated through the beta decay of In-133 at the ISOLDE facility. The ISOLDE Resonance Ionization Laser Ion Source (RILIS) provided isomer-selective ionization for In-133, allowing us to study separately, and in detail, the beta-decay branch of In-133 J(pi)= (9/2(+)) ground state and its J(pi) = (1/2(-)) isomer.Thanks to the large spin difference of the two beta-decaying states of In-133, it is possible to investigate separately the lower and higher spin states in the daughter, Sn-133, and thus to probe independently different single-particle and single-hole levels. We report here new gamma transitions observed in the decay of In-133, including those assigned to the deexcitation of the neutron-unbound states.

Published
2019

32. Large Impact of the Decay of Niobium Isomers on the Reactor ν¯e Summation Calculations

Author

M. Lebois, Tommi Eronen, Ilkka Pohjalainen, V. Guadilla, L. M. Fraile, Juha Äystö, J. A. Briz, Mikael Reponen, Jani Hakala, Jukka Koponen, Amanda Porta, Enrique Nácher, E. Ganioglu, T. Martinez, J. N. Wilson, A.-A. Zakari-Issoufou, M. Estienne, Volker Sonnenschein, Annika Voss, A. A. Sonzogni, E. Valencia, M. Monserrate, W. Gelletly, Muriel Fallot, Heikki Penttilä, Juuso Reinikainen, D. Jordan, Ari Jokinen, L. Le Meur, A. Algora, K. Rytkönen, A. Cucoanes, Iain Moore, Anu Kankainen, S. E. A. Orrigo, Veli Kolhinen, Dmitry Gorelov, T. Shiba, A. Montaner-Pizá, V. Vedia, Sami Rinta-Antila, Berta Rubio, J. L. Tain, and Jorge Agramunt

Subjects
Semileptonic decay, Physics, Isotope, Niobium, General Physics and Astronomy, chemistry.chemical_element, Penning trap, 7. Clean energy, 01 natural sciences, Beta decay, Ion, Nuclear physics, chemistry, 13. Climate action, Beta (plasma physics), 0103 physical sciences, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The beta-intensity distributions of Nb-100gs,Nb-100m and Nb-102gs,Nb-02m beta decays have been determined using the total absorption.-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyvaskyla. Here, the double Penning trap system JYFLTRAP was employed to disentangle the beta decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced.

Published
2019

33. Lifetimes and shape-coexisting states of $^{99}Zr$

Author

J. F. Smith, N. Saed-Samii, R. Lica, G. S. Simpson, V. Werner, L. M. Fraile, C. Bernards, W. Korten, S. Lalkovski, P. H. Regan, T. Kröll, N. Marginean, A. Vancraeyenest, Torsten Soldner, Paolo Mutti, P. Spagnoletti, V. Paziy, F. Drouet, C. Townsley, Marcus Scheck, Liam Gaffney, Henryk Mach, J. Jolie, G Thiamova, M. Zielińska, J.-M. Régis, C. A. Ur, N. Warr, S. Ilieva, Michael Jentschel, S. Kisyov, W. Urban, Aurelien Blanc, Zs. Podolyák, Ulli Köster, D. Ghita, Alison Bruce, C. Larijarni, D. Bucurescu, V. Vedia, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Laue-Langevin (ILL), ILL, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Physics, 010308 nuclear & particles physics, Fission, Nuclear structure, Shell (structure), Deformation (meteorology), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 01 natural sciences, medicine.anatomical_structure, Beamline, Excited state, 0103 physical sciences, Quadrupole, medicine, Física nuclear, Nuclear Physics - Experiment, Atomic physics, 010306 general physics, Nucleus
Abstract

Lifetimes of intermediate-spin states in two rotational bands of 99Zr have been measured. These states were populated following the neutron-induced fission of 235U at the PF1B beamline of the Institut Laue-Langevin, Grenoble, during the EXILL-FATIMA campaign. The nucleus 99Zr59 exhibits shape coexistence and lies precisely on the border of an abrupt change in ground-state deformation when going from N=58 to N=60, making its study interesting for understanding the mechanisms involved in the rapid onset of deformation here. The B(E2) values extracted for decays in the ν3/2[541] band allow quadrupole deformations of β2=0.34(1) and 0.26(3) to be determined for the 821.6- and 1236.6-keV members, whereas β2=0.32(3) was found for the 850.5-keV member of the ν3/2[411]band. Some of the excited states known in 99Zr have been reasonably described with interacting boson-fermion model (IBFM) calculations. Type-II shell evolution is proposed to play a major role in modifying single-particle energies in 99Zr.

Published
2019

34. Total absorption γ -ray spectroscopy of niobium isomers

Author

Ilkka Pohjalainen, A. Montaner-Pizá, Tommi Eronen, Dmitry Gorelov, E. Valencia, M. Monserrate, José Antonio Briz, B. Rubio, V. Vedia, Iain Moore, Sami Rinta-Antila, Anu Kankainen, S. E. A. Orrigo, V. Guadilla, Jani Hakala, Muriel Fallot, W. Gelletly, Juha Äystö, D. Jordan, Mikael Reponen, A.-A. Zakari-Issoufou, Heikki Penttilä, L. M. Fraile, J. L. Tain, A. A. Sonzogni, Pedro Sarriguren, Annika Voss, Volker Sonnenschein, Jorge Agramunt, A. Cucoanes, Jukka Koponen, E. Ganioglu, Enrique Nácher, M. Estienne, T. Martinez, M. Lebois, Amanda Porta, J. N. Wilson, T. Shiba, K. Rytkönen, V. Kolhinen, Ari Jokinen, L. Le Meur, A. Algora, Juuso Reinikainen, 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)-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), 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), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Consejo Superior de Investigaciones Científicas (España), European Science Foundation, Science and Technology Facilities Council (UK), Academy of Finland, International Atomic Energy Agency, Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), 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
spektroskopia, Niobium, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 7. Clean energy, 01 natural sciences, 0103 physical sciences, Decay heat, 010306 general physics, Spectroscopy, Absorption (electromagnetic radiation), Nuclear Experiment, Physics, Zirconium, Spectrometer, 010308 nuclear & particles physics, Pandemonium effect, Penning trap, nuclear structure and decays, chemistry, 13. Climate action, Física nuclear, beta decay, Atomic physics, isomer decays, ydinfysiikka
Abstract

15 pags. 17 figs., 5 tabs., The β-intensity distributions of the decays of Nb100gs,100m and Nb102gs,102m have been determined using the total absorption γ-ray spectroscopy technique. The JYFLTRAP double Penning trap system was employed in a campaign of challenging measurements performed with the decay total absorption γ-ray spectrometer at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. Different strategies were applied to disentangle the isomeric states involved, lying very close in energy. The low-spin component of each niobium case was populated through the decay of the zirconium parent, which was treated as a contaminant. We have applied a method to extract this contamination, and additionally we have obtained β-intensity distributions for these zirconium decays. The β-strength distributions evaluated with these results were compared with calculations in a quasiparticle random-phase approximation, suggesting a prolate configuration for the ground states of Zr100,102. The footprint of the Pandemonium effect was found when comparing our results for the analyses of the niobium isotopes with previous decay data. The β-intensities of the decay of Nb102m, for which there were no previous data, were obtained. A careful evaluation of the uncertainties was carried out, and the consistency of our results was validated taking advantage of the segmentation of our spectrometer. The final results were used as input in reactor summation calculations. A large impact on antineutrino spectrum calculations was already reported, and here we detail the significant impact on decay heat calculations., This work has been supported by the Spanish Ministerio de Economía y Competitividad under Grants No. FPA2011- 24553, No. AIC-A-2011-0696, No. FPA2014-52823-C2-1- P, No. FPA2015-65035-P, No. FPI/BES-2014-068222, No. FPA2017-83946-C2-1-P, and the program Severo Ochoa (SEV-2014-0398), by the Spanish Ministerio de Educación under the FPU12/01527 Grant, by the European Commission under the FP7/EURATOM Contract No. 605203 and the FP7/ENSAR Contract No. 262010, and by the Junta para la Ampliación de Estudios Programme (CSIC JAE-Doc contract) co-financed by ESF. We acknowledge the support of the UK Science and Technology Facilities Council (STFC) Grant No. ST/P005314/1. This work was also supported by the Academy of Finland under the Finnish Centre of Excellence Programme (Project No. 213503, Nuclear and AcceleratorBased Physics Research at JYFL). The authors thank the IAEA for supporting and encouraging the work in this field.

Published
2019

35. Large Impact of the Decay of Niobium Isomers on the Reactor ν[over ¯]_{e} Summation Calculations

Author

V, Guadilla, A, Algora, J L, Tain, M, Estienne, M, Fallot, A A, Sonzogni, J, Agramunt, J, Äystö, J A, Briz, A, Cucoanes, T, Eronen, L M, Fraile, E, Ganioğlu, W, Gelletly, D, Gorelov, J, Hakala, A, Jokinen, D, Jordan, A, Kankainen, V, Kolhinen, J, Koponen, M, Lebois, L, Le Meur, T, Martinez, M, Monserrate, A, Montaner-Pizá, I, Moore, E, Nácher, S E A, Orrigo, H, Penttilä, I, Pohjalainen, A, Porta, J, Reinikainen, M, Reponen, S, Rinta-Antila, B, Rubio, K, Rytkönen, T, Shiba, V, Sonnenschein, E, Valencia, V, Vedia, A, Voss, J N, Wilson, and A-A, Zakari-Issoufou

Abstract

Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of ^{100gs,100m}Nb and ^{102gs,102m}Nb β decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the β decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced.

Published
2018

36. Reaction Channel selection techniques and γ – γ fast-timing spectroscopy using the ν-Ball Spectrometer

Author

V. Karayonchev, L. Qi, C. R. Niţă, Gavin Lotay, Mohammad Nakhostin, Ł. W. Iskra, N. Cieplicka-Oryńczak, A. R. L. Kennington, J.-M. Régis, S. Bottoni, Sean Collins, S. Courtin, P. H. Regan, D. Thisse, V. Vedia, M. Heine, Giuseppe Lorusso, J. N. Wilson, R. Shearman, M. Lebois, Stephan Oberstedt, P. A. Söderström, M. Rudigier, P. Koseoglou, N. Jovančević, W. Witt, J. Benito, M. Brunet, Zs. Podolyák, K. Hadynska-Klek, D. T. Doherty, R.L. Canavan, L. M. Fraile, Institut de Physique Nucléaire d'Orsay (IPNO), 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), Institut Pluridisciplinaire Hubert Curien (IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
History, Materials science, Spectrometer, 010308 nuclear & particles physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computer Science Applications, Education, 0103 physical sciences, Ball (bearing), Physics::Accelerator Physics, Física nuclear, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

The reaction of a pulsed 18O beam on a self-supporting and gold-backed isotopically-enriched 164Dy target of thickness 6.3 mg/cm2 at separate primary beam energies of 71, 76 and 80 MeV was studied at the accelerator at the ALTO facility of the IPN Orsay. The γ rays produced were detected using the newly-constructed ν-Ball spectrometer which comprised of HPGe and LaBr3(Ce) detectors. This conference paper describes the methodology and effectiveness of multiplicity/sum-energy gating, for channel selection between fusion evaporation events and lower multiplicity/energy events from inelastic nuclear scattering and Coulomb excitation of the target, and from two-neutron transfer reactions to 166Dy.

Published
2020

37. The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus 133Sb

Author

B. Fornal, Alison Bruce, G. Benzoni, W. Korten, Raymond J. Carroll, R. Lozeva, Zs. Podolyák, G. Bocchi, A. Nannini, D. R. Napoli, B. Olaizola, Henryk Mach, J. Jolie, D. Mengoni, G. S. Simpson, V. Vedia, D. Bazzacco, Michael Jentschel, F. Didierjean, B. Belvito, N. Saed-Samii, C. A. Ur, N. Cieplicka-Oryǹczak, B. Melon, W. Urban, J.-M. Régis, Torsten Soldner, P. H. Regan, N. Marginean, F. C. L. Crespi, V. Paziy, L. M. Fraile, C. Michelagnoli, B. Szpak, B. Million, T. Kröll, Aurelien Blanc, P. Mutti, A. Bracco, Ulli Köster, Pier Francesco Bortignon, S. Leoni, Gianluca Colò, S. Bottoni, S. Lalkovski, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, Large Ge array, Fission, Neutron induced fission, FOS: Physical sciences, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Nuclear Theory (nucl-th), Gamma spectroscopy, Nuclear state lifetime, Particle-core couplings, 0103 physical sciences, medicine, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Valence (chemistry), 010308 nuclear & particles physics, Yrast, lcsh:QC1-999, medicine.anatomical_structure, Excited state, Física nuclear, Atomic physics, Nucleus, Order of magnitude, lcsh:Physics
Abstract

The gamma-ray decay of excited states of the one-valence-proton nucleus Sb-133 has been studied using cold-neutron induced fission of U-235 and Pu-241 targets, during the EXILL campaign at the ILL reactor in Grenoble. By using a highly efficient HPGe array, coincidences between gamma-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 mu s isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr3(Ce) scintillators, revealed a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus Sn-132 and the valence proton, using Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

Published
2016

38. Summation Calculations for Reactor Antineutrino Spectra, Decay Heat and Delayed Neutron Fractions Involving New TAGS Data and Evaluated Databases

Author

T. Shiba, M. Monserrate, L. Giot, M. Fallot, W. Gelletly, Juha Äystö, A. Cucoanes, Iain Moore, L. M. Fraile, M. Reponen, Jani Hakala, Anu Kankainen, S. E. A. Orrigo, José Antonio Briz, Veli Kolhinen, V. Vedia, Sami Rinta-Antila, C. Weber, Jukka Koponen, Enrique Nácher, Dmitry Gorelov, T. Martinez, Jorge Agramunt, M. Estienne, Annika Voss, J. L. Tain, E. Valencia, E. Ganogliu, J. N. Wilson, M. Lebois, A. Porta, V. Guadilla-Gomez, Tommi Eronen, K. Rytkönen, Ari Jokinen, L. Le Meur, A. Algora, Ilkka Pohjalainen, S. Cormon, A. Montaner-Pizá, Berta Rubio, M. D. Jordan, Heikki Penttilä, Volker Sonnenschein, A.-A. Zakari-Issoufou, Alejandro Sonzogni, Juuso Reinikainen, 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), Serot, O., Chebboubi, A., 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), and SCOAP

Subjects
Nuclear fission product, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Fission, QC1-999, Nuclear Theory, 114 Physical sciences, 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, SPECTROMETER, Gamma spectroscopy, Decay heat, 010306 general physics, Nuclear Experiment, Physics, [PHYS]Physics [physics], Fission products, 010308 nuclear & particles physics, Nuclear data, Física nuclear, High Energy Physics::Experiment, Delayed neutron, Radioactive decay
Abstract

9 pags., 3 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0, Three observables of interest for present and future reactors depend on the β decay properties of the fission products: antineutrinos from reactors, the reactor decay heat and delayed neutron emission. In these proceedings, we present new results from summation calculations of the first two quantities quoted above, performed with evolved independent yields coupled with fission product decay data, from various nuclear data bases or models. New TAGS results from the latest experiment of the TAGS collaboration at the JYFL facility of Jyväskylä will be displayed as well as their impact on the antineutrino spectra and the decay heat associated to fission pulses of the main actinides.

Published
2018

39. First Accurate Normalization of the β -delayed α Decay of N16 and Implications for the C12(α,γ)O16 Astrophysical Reaction Rate

Author

Oliver S. Kirsebom, H. De Witte, L. J. Harkness-Brennan, P. Rahkila, Jesper Hasseriis Mohr Jensen, P. Díaz Fernández, Esben Rohan Christensen, V. F. E. Pucknell, Ángel Perea, Björn Jonson, M. Munch, K. Riisager, P. Van Duppen, M.C. Gallardo, A. Negret, R. Mărginean, R. Lica, R. D. Page, María José García Borge, M. V. Lund, D.T. Doherty, O. Sorlin, T. Berry, N. Warr, Miguel Madurga, L. M. Fraile, H. Törnqvist, Paul Greenlees, J. A. Swartz, Andrei Andreyev, H. O. U. Fynbo, Olof Tengblad, N. Hubbard, I. Marroquin, C. Sotty, Håkan T Johansson, V. Vedia, Marc Huyse, D. S. Judson, H.B. Sørensen, C. Mihai, I.H. Lazarus, N. Marginean, and Joonas Konki

Subjects
Physics, Nuclear reaction, Nuclear physics, Reaction rate, Normalization (statistics), Light nucleus, 010308 nuclear & particles physics, Branching fraction, 0103 physical sciences, General Physics and Astronomy, Alpha decay, 010306 general physics, 01 natural sciences
Abstract

The C-12(alpha,gamma)O-16 reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced a width, gamma(11), of the bound 1(-) level in O-16 is particularly important to determine the cross section. The magnitude of gamma(11) is determined via sub-Coulomb a-transfer reactions or the beta-delayed a decay of N-16, but the latter approach is presently hampered by the lack of sufficiently precise data on the beta-decay branching ratios. Here we report improved branching ratios for the bound 1(-) level [b(beta,11) = (5.02 +/- 0.10) x 10(-2)] and for beta-delayed alpha emission [b(beta alpha) = (1.59 +/- 0.06) x 10(-5)]. Our value for b(beta alpha) is 33% larger than previously held, leading to a substantial increase in gamma(11). Our revised value for gamma(11) is in good agreement with the value obtained in a-transfer studies and the weighted average of the two gives a robust and precise determination of gamma(11), which provides significantly improved constraints on the C-12(alpha,gamma) cross section in the energy range relevant to hydrostatic He burning.

Published
2018

40. Characterization and performance of the DTAS detector

Author

J. N. Wilson, M. Monserrate, K. Rytkönen, Ilkka Pohjalainen, D. Jordan, Stephen Rice, V. Guadilla, Annika Voss, A.-A. Zakari-Issoufou, M. Lebois, Juha Äystö, Mikael Reponen, Muriel Fallot, S.E.A. Orrigo, E. Ganioglu, Tommi Eronen, Ari Jokinen, A. A. Sonzogni, Jukka Koponen, L. Le Meur, Juuso Reinikainen, M. Estienne, Enrique Nácher, Heikki Penttilä, Volker Sonnenschein, L. M. Fraile, Jani Hakala, E. Valencia, A. Cucoanes, Iain Moore, Anu Kankainen, Veli Kolhinen, Dmitry Gorelov, A. Montaner-Pizá, Berta Rubio, W. Gelletly, J. A. Briz, T. Martinez, T. Shiba, Jorge Agramunt, Alejandro Algora, J. L. Tain, Amanda Porta, V. Vedia, Sami Rinta-Antila, European Commission, Science and Technology Facilities Council (UK), Istanbul University, Ministerio de Economía y Competitividad (España), 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), 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), Université de Nantes - Faculté des Sciences et des Techniques, 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
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, spektrometrit, β decay, FOS: Physical sciences, Non-proportional scintillation light yield: Monte Carlo simulations, Monte Carlo simulations [Non-proportional scintillation light yield], y-ray spectrometer, B decay, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Monte Carlo simulations, Optics, Distortion, 0103 physical sciences, Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), 010306 general physics, Absorption (electromagnetic radiation), Nuclear Experiment, Instrumentation, [formula omitted] decay, Physics, ta114, Spectrometer, 010308 nuclear & particles physics, business.industry, NaI(Tl) detector, Pulse generator, Total absorption [formula omitted]-ray spectrometer, Detector, non-proportional scintillation light yield, Instrumentation and Detectors (physics.ins-det), Total absorption γ -ray spectrometer, Non-proportional scintillation light yield, Física nuclear, Total absorption, ydinfysiikka, business, Delayed neutron, Exotic nuclei
Abstract

11 pags., 16 figs., 3 tabs., DTAS is a segmented total absorption γ-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 γ-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 β-delayed neutron emitting nuclei., This work has been supported by the Spanish Ministerio de Economia y Competitividad under grants FPA2011-24553, AIC-A-2011-0696, FPA2014-52823-C2-1-P and the program Severo Ochoa (SEV-2014-0398), by the European Commission under the FP7/EURATOM contract 605203, and by the Spanish Ministerio de Educacion Cultura y Deporte under the FPU12/01527 grant. The work was also supported by the UK Science and Technology Facilities Council (STFC) grant 14 ST/P005314/1. E. Ganioglu was supported by the Istanbul University Scientic Research Project Unit under FYO-2017-24144 project.

Published
2018

41. Investigation of low-lying states in 133sn populated in the - Decay of 133in using isomer-selective laser ionization

Author

A. Villa, T. Berry, M. J. G. Borge, V. Sánchez-Tembleque, A. Illana, M. Carmona, B. A. Marsh, M. Stanoiu, C. Costache, L. M. Fraile, G. Correia, S. Paulaskalas, G. Fernández-Martínez, R. Álvarez, V. Karanyonchev, M. Stryjczyk, M. Madurga, W. B. Walters, C. Martínez, K. Chrysalidis, T. Day Goodacre, M. Piersa, G. S. Simpson, A. Turturica, G. Benzoni, M. Kicinska-Habior, A. E. Barzakh, D. V. Fedorov, D. Galaviz, V. Vedia, M. Fila, C. Henrich, R. E. Mihai, J. Benito, Sebastian Rothe, J. M. Udías, Karl Johnston, L. Stan, Robert Grzywacz, E. Adamska, I. Marroquin, A. Korgul, K. Miernik, B. Olaizola, V. N. Fedosseev, C. Mazzocchi, Z. Janas, Ch. Sotty, R. Lica, J.-M. Régis, National Science Centre (Poland), Fundação para a Ciência e a Tecnologia (Portugal), SCOAP, Ministerio de Economía y Competitividad (España), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
Physics, Isotope, 010308 nuclear & particles physics, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Laser, 01 natural sciences, Beta decay, 3. Good health, law.invention, law, Ionization, Excited state, 0103 physical sciences, Física nuclear, Beta (velocity), Atomic physics, 010306 general physics
Abstract

6 pags., 3 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0. -- Presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Poland, September 3–9, 2017., Excited states in the neutron-rich isotope 133Sn were studied via the ß decay of 133In. Isomer selective ionization using the ISOLDE RILIS enabled the ß decays of 133Ings (I¿ = 9=2+) and 133mIn (II¿ = 1=2-) to be studied independently for the first time. A description of the experimental setup at the ISOLDE Decay Station is presented together with preliminary results from the experiment., This work was supported in part by the National Science Centre, Poland (NCN) under contracts No. UMO-2015/18/E/ST2/00217 and No. UMO- 2015/18/M/ST2/00523, by the Spanish MINECO via FPA2015-65035-P project and by the Portuguese FCT via CERN/FIS-NUC/0004/2015 project.

Published
2018

42. Evolution of deformation in neutron-rich Ba isotopes up to A = 150

Author

R. Lică, G. Benzoni, T. R. Rodríguez, M. J. G. Borge, L. M. Fraile, H. Mach, A. I. Morales, M. Madurga, C. O. Sotty, V. Vedia, H. De Witte, J. Benito, R. N. Bernard, T. Berry, A. Bracco, F. Camera, S. Ceruti, V. Charviakova, N. Cieplicka-Oryńczak, C. Costache, F. C. L. Crespi, J. Creswell, G. Fernandez-Martínez, H. Fynbo, P. T. Greenlees, I. Homm, M. Huyse, J. Jolie, V. Karayonchev, and U. Köster

Published
2018
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43. Experimental study of the lifetime and phase transition in neutron-rich Zr98,100,102

Author

O. Stezowski, Tomoaki Togashi, S. Ansari, F. Drouet, N. Saed-Samii, G. S. Simpson, E. Wilson, S. Ilieva, C. A. Ur, W. Korten, V. Paziy, M. D. Salsac, C. Townsley, A. Vancraeyenest, L. M. Fraile, Marcus Scheck, Paolo Mutti, Emyr Clement, B. Olaizola, Henryk Mach, J. Jolie, J.-M. Régis, J. F. Smith, V. Vedia, Oliver J. Roberts, M. Zielińska, Raymond J. Carroll, Zs. Podolyák, W. Urban, Takaharu Otsuka, A. Ignatov, S. Lalkovski, P. H. Regan, N. Marginean, T. Soldner, C. Larijani, Alison Bruce, Yusuke Tsunoda, A.-L. Hartig, T. Kröll, Noritaka Shimizu, Aurelien Blanc, Ulli Köster, N. Warr, and Michael Jentschel

Subjects
Physics, Phase transition, 010308 nuclear & particles physics, Fission, Context (language use), Neutron radiation, 01 natural sciences, 7. Clean energy, Excited state, 0103 physical sciences, Neutron, Atomic physics, Interacting boson model, Nuclear Experiment, 010306 general physics, Line (formation)
Abstract

Rapid shape changes are observed for neutron-rich nuclei with A around 100. In particular, a sudden onset of ground-state deformation is observed in the Zr and Sr isotopic chains at N = 60: Low-lying states in $N\ensuremath{\le}58$ nuclei are nearly spherical, while those with $N\ensuremath{\ge}60$ have a rotational character. Nuclear lifetimes as short as a few picoseconds can be measured using fast-timing techniques with ${\mathrm{LaBr}}_{3}$(Ce) scintillators, yielding a key ingredient in the systematic study of the shape evolution in this region. We used neutron-induced fission of $^{241}\mathrm{Pu}$ and $^{235}\mathrm{U}$ to study lifetimes of excited states in fission fragments in the $A\ensuremath{\sim}100$ region with the EXILL-FATIMA array located at the PF1B cold neutron beam line at the Institut Laue-Langevin. In particular, we applied the generalized centroid difference method to deduce lifetimes of low-lying states for the nuclei $^{98}\mathrm{Zr}$ (N = 58), $^{100}\mathrm{Zr}$, and $^{102}\mathrm{Zr}$ ($N\ensuremath{\ge}60$). The results are discussed in the context of the presumed phase transition in the Zr chain by comparing the experimental transition strengths with the theoretical calculations using the interacting boson model and the Monte Carlo shell model.

Published
2017

44. Optimizing Time-Pickup Algorithms in Radiation Detectors with a Genetic Algorithm

Author

J. M. Udías, V. Sánchez-Tembleque, V. Vedia, and L. M. Fraile

Subjects
education.field_of_study, business.industry, Computer science, Detector, Population, Dynode, Constant fraction discriminator, Particle detector, Data acquisition, business, education, Digital filter, Algorithm, Digital signal processing
Abstract

Pulse digitation at high rates has opened the way to employ complex, non-standard algorithms to obtain the timestamps of gamma photons arriving to nuclear detectors, beyond the conventional constant fraction discriminator (CFD) option. Detector pulses can be shaped with digital filters by means of DSP hardware, and timestamps can be derived interpolating and/or, extrapolating the samples acquired. Digitized pulses can be stored in a computer for off-line analysis which makes it possible to try many different algorithm variations on the same data. Very soon, the number of filters and parameters to tune in order to optimize the best timing performance becomes too large. In this work we use a genetic algorithm to tune the in-silico digital filter, digital time pickup algorithm and associated parameters. The data set consisted in 500,000 pulses obtained from the last dynode of an ultrafast PMT (model R9779 form Hamamatsu) coupled to large monolithic inorganic BrLa(Ce) scintillators, in both truncated cone 1.5” $\times 1 '' \times 1.5$” . With finely tuned conventional (CFD +TAC) timing electronics, CRT of 155 ps (FWHM) have been obtained in our group, results that represent the state of the art with detectors this size. Our alternate digital, in-silico implementation of CFD+TAC, fine tuned with the same parameters obtained during manual adjustment of the conventional DAQ, and applied to pulses digitized at 5 GS/s and 12 bits, reproduces the performance of the conventional DAQ. On the other hand, a genetic algorithm (GA) is employed to optimize digital recursive filters with up to 8 parameters, and different time-pickup strategies (upper level tresholding, CFD, time extrapolation). The same 500,000 pulses are employed to test the fitness of the population in the GA. The GA finds several families of filters outperforming by more than 8% the performance of the algorithm tuned manually.

Published
2017

45. Search for the Ga73 ground-state doublet splitting in the β decay of Zn73

Author

W. B. Walters, R. Lica, G. S. Simpson, P. Hoff, J.-M. Régis, L. M. Fraile, Ani Aprahamian, Z. Dlouhý, W. Kurcewicz, Ulli Köster, Brian Bucher, L. Stroe, V. Vedia, José Antonio Briz, T. Sava, M. Rudigier, R. Mărginean, Henryk Mach, J. Jolie, N. Marginean, C. J. Chiara, V. Paziy, C. Bernards, B. Olaizola, M. Stanoiu, D. Ghiţă, and Ioana Gheorghe

Subjects
Physics, Work (thermodynamics), Large Hadron Collider, 010308 nuclear & particles physics, New energy, Coulomb excitation, State (functional analysis), 01 natural sciences, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Ground state, Spectroscopy
Abstract

The existence of two close-lying nuclear states in ⁷³Ga has recently been experimentally determined: a 1/2⁻ spin-parity for the ground state was measured in a laser spectroscopy experiment, while a J_π = 3/2⁻ level was observed in transfer reactions. This scenario is supported by Coulomb excitation studies, which set a limit for the energy splitting of 0.8 keV. In this work, we report on the study of the excited structure of ⁷³Ga populated in the β decay of ⁷³Zn produced at ISOLDE, CERN. Using β-gated, γ-ray singles, and γ –γ coincidences, we have searched for energy differences to try to delimit the ground-state energy splitting, providing a more stringent energy difference limit. Three new half-lives of excited states in ⁷³Ga have been measured using the fast-timing ;method with LaBr₃(Ce) detectors. From our study, we help clarify the excited structure of ⁷³G and we extend the existing ⁷³Zn decay to ⁷³Ga with 8 new energy levels and 35 γ transitions. We observe a 195-keV transition consistent with a γ ray de-exciting a short-lived state in the β-decay parent ⁷³Zn.

Published
2017

46. Experimental study of Tc100 β decay with total absorption γ -ray spectroscopy

Author

V. Vedia, Osvaldo Civitarese, Sami Rinta-Antila, E. Ganioglu, A.-A. Zakari-Issoufou, A. Cucoanes, Jukka Koponen, Enrique Nácher, A. Montaner-Pizá, José Antonio Briz, Ari Jokinen, W. Gelletly, Jouni Suhonen, Heikki Penttilä, J. N. Wilson, A. Algora, Ilkka Pohjalainen, Juha Äystö, M. Estienne, Mikael Reponen, D. Jordan, B. Rubio, L. M. Fraile, Muriel Fallot, K. Rytkönen, Jorge Agramunt, V. Guadilla, M. Lebois, Tommi Eronen, M. Monserrate, Volker Sonnenschein, A. A. Sonzogni, T. Martinez, J. L. Tain, Jani Hakala, Annika Voss, T. Shiba, E. Valencia, Juuso Reinikainen, Iain Moore, Anu Kankainen, S. E. A. Orrigo, Veli Kolhinen, Dmitry Gorelov, and Amanda Porta

Subjects
Physics, 010308 nuclear & particles physics, Branching fraction, Gamma ray, 01 natural sciences, Beta decay, Double beta decay, 0103 physical sciences, Gamma spectroscopy, Atomic physics, 010306 general physics, Ground state, Spectroscopy, Absorption (electromagnetic radiation)
Abstract

The beta decay of Tc-100 has been studied by using the total absorption gamma-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyvaskyla. In this work the new Decay Total Absorption gamma-ray Spectrometer in coincidence with a cylindrical plastic beta detector has been employed. The beta intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximation framework are also reported. Comparison of these calculations with our measurement serves as a benchmark for calculations of the double beta decay of Mo-100.

Published
2017

47. Erratum: Abrupt shape transition at neutron number N=60 : B(E2) values in Sr94,96,98 from fast γ−γ timing [Phys. Rev. C 95 , 054319 (2017)]

Author

J.-M. Régis, J. Jolie, N. Saed-Samii, N. Warr, M. Pfeiffer, A. Blanc, M. Jentschel, U. Köster, P. Mutti, T. Soldner, G. S. Simpson, F. Drouet, A. Vancraeyenest, G. de France, E. Clément, O. Stezowski, C. A. Ur, W. Urban, P. H. Regan, Zs. Podolyák, C. Larijani, C. Townsley, R. Carroll, E. Wilson, L. M. Fraile, H. Mach, V. Paziy, B. Olaizola, V. Vedia, A. M. Bruce, O. J. Roberts, J. F. Smith, M. Scheck, T. Kröll, A.-L. Hartig, A. Ignatov, S. Ilieva, S. Lalkovski, W. Korten, N. Mărginean, T. Otsuka, N. Shimizu, T. Togashi, and Y. Tsunoda

Subjects
Physics, Neutron number, Atomic physics
Published
2017

48. Abrupt shape transition at neutron number N=60 : B(E2) values in Sr94,96,98 from fast γ−γ timing

Author

J.-M. Régis, J. Jolie, N. Saed-Samii, N. Warr, M. Pfeiffer, A. Blanc, M. Jentschel, U. Köster, P. Mutti, T. Soldner, G. S. Simpson, F. Drouet, A. Vancraeyenest, G. de France, E. Clément, O. Stezowski, C. A. Ur, W. Urban, P. H. Regan, Zs. Podolyák, C. Larijani, C. Townsley, R. Carroll, E. Wilson, L. M. Fraile, H. Mach, V. Paziy, B. Olaizola, V. Vedia, A. M. Bruce, O. J. Roberts, J. F. Smith, M. Scheck, T. Kröll, A.-L. Hartig, A. Ignatov, S. Ilieva, S. Lalkovski, W. Korten, N. Mărginean, T. Otsuka, N. Shimizu, T. Togashi, and Y. Tsunoda

Subjects
Physics, Fission products, Proton, Isotope, 010308 nuclear & particles physics, Fission, Yrast, Nuclear Theory, Monte Carlo method, 7. Clean energy, 01 natural sciences, Nuclear physics, 13. Climate action, Neutron number, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

Lifetimes of low-lying yrast states in neutron-rich 94,96,98Sr have been measured by Germanium-gated γ−γ fast timing with LaBr3(Ce) detectors using the EXILL&FATIMA spectrometer at the Institut Laue-Langevin. Sr fission products were generated using cold-neutron-induced fission of 235U and stopped almost instantaneously within the thick target. The experimental B(E2) values are compared with results of Monte Carlo shell-model calculations made without truncation on the occupation numbers of the orbits spanned by eight proton and eight neutron orbits and show good agreement. Similarly to the Zr isotopes, the abrupt shape transition in the Sr isotopes near neutron number N=60 is identified as being caused by many-proton excitations to its g9/2 orbit.

Published
2017

49. Characterization of a cylindrical plastic {\beta}-detector with Monte Carlo simulations of optical photons

Author

J. L. Tain, K. Rytkönen, W. Gelletly, Juha Äystö, A. Cucoanes, Mikael Reponen, Ari Jokinen, E. Ganioglu, Volker Sonnenschein, Juuso Reinikainen, Heikki Penttilä, S.E.A. Orrigo, D. Jordan, Tommi Eronen, Dmitry Gorelov, José Antonio Briz, M. Lebois, A. Porta, B. Rubio, Jorge Agramunt, T. Martinez, L. M. Fraile, M. Estienne, Jukka Koponen, Annika Voss, Enrique Nácher, J. N. Wilson, Iain Moore, V. Vedia, Sami Rinta-Antila, Anu Kankainen, T. Shiba, Veli Kolhinen, A.-A. Zakari-Issoufou, V. Guadilla, E. Valencia, M. Monserrate, M. Fallot, A. Algora, Jani Hakala, Ilkka Pohjalainen, A. Montaner-Pizá, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Ministerio de Educación (España), European Commission, and Ministerio de Economía y Competitividad (España)

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Photon, Total absorption spectroscopy, optical photons, Monte Carlo method, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Electromagnetic radiation, Monte Carlo simulations, Optics, 0103 physical sciences, Plastic scintillators, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], plastic scintillators, 010306 general physics, Absorption (electromagnetic radiation), Nuclear Experiment, Instrumentation, Physics, Spectrometer, ta114, 010308 nuclear & particles physics, business.industry, Detector, total absorption spectroscopy, Computational physics, Optical photons, Dynamic Monte Carlo method, business
Abstract

V. Guadilla et al. -- 5 pags., 8 figs., tab., In this work we report on the Monte Carlo study performed to understand and reproduce experimental measurements of a new plastic β-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 γ-ray spectroscopy analysis., This work has been supported by the Spanish Ministerio de Economía y Competitividad under grants FPA2011-24553, AIC-A-2011-0696, FPA2014-52823-C2-1-P and the program Severo Ochoa (SEV-2014-0398), by the European Commission under the FP7/EURATOM contract 605203, and by the Spanish Ministerio de Educación under the FPU12/01527 grant.

Published
2017

50. Publisher's Note: Half-life of the 15/2+ state of I135 : A test of E2 seniority relations [Phys. Rev. C 95 , 021302(R) (2017)]

Author

W. Korten, V. Vedia, T. Soldner, T. Kroell, Henryk Mach, J. Jolie, U. Koester, Paolo Mutti, P. Spagnoletti, W. Urban, S. Lalkovski, P. H. Regan, N. Marginean, G. S. Simpson, J.-M. Régis, R. Lica, A. Gargano, G. Thiamova, S. Ilieva, Michael Jentschel, L. M. Fraile, A. Vancraeyenest, P. Van Isacker, N. Saed-Samii, Liam Gaffney, Marcus Scheck, Raymond J. Carroll, C. A. Ur, Zs. Podolyák, D. Ghita, C. Townsley, Alison Bruce, V. Paziy, C. Larijani, Aurelien Blanc, and F. Drouet

Subjects
Physics, Seniority, State (functional analysis), Test (assessment), Mathematical physics
Published
2017

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