Author: "I, Matea" - Searchworks@Jio Institute Digital Library Search Results

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185 results on '"I, Matea"'

1. The decay of the 21.47-MeV stretched resonance in 13C: A precise probe of the open nuclear quantum system description

Author: N. Cieplicka-Oryńczak, Y. Jaganathen, B. Fornal, S. Leoni, M. Płoszajczak, M. Ciemała, S. Ziliani, M. Kmiecik, A. Maj, J. Łukasik, P. Pawłowski, B. Sowicki, B. Wasilewska, M. Ziębliński, P. Bednarczyk, C. Boiano, S. Bottoni, A. Bracco, S. Brambilla, I. Burducea, F. Camera, I. Ciepał, C. Clisu, F.C.L. Crespi, K. Dhanmeher, N. Florea, E. Gamba, J. Grębosz, M.N. Harakeh, D.A. Iancu, Ł.W. Iskra, M. Krzysiek, P. Kulessa, N. Marginean, R. Marginean, I. Matea, M. Matejska-Minda, K. Mazurek, B. Million, W. Parol, M. Sferrazza, L. Stan, and B. Włoch
Subjects: 13C, Nuclear structure, Stretched resonance states, Gamow Shell Model, Physics, QC1-999
Abstract: The decay of the 21.47-MeV stretched resonance in 13C, arising from p3/2→d5/2 nucleon excitation coupled to maximum spin, was investigated in a (p,p′) experiment at 135 MeV proton bombarding energy, performed at the Cyclotron Centre Bronowice (CCB) at IFJ PAN in Krakow. First experimental information on the proton and neutron decay branches from this state was obtained by using coincidence measurement of protons inelastically scattered on a 13C target and γ rays from daughter nuclei, namely, 12B (proton decay) and 12C (neutron decay). The main branches lead to the Jπ=2+, first-excited state at 0.953 MeV in 12B, and to the Jπ=1+, T=1 level at 15.110 MeV in 12C. The results were compared with predictions from the Gamow Shell Model (GSM), which was used to describe the stretched resonance in terms of its energy, width, electromagnetic transition strengths and decay pattern. A very good agreement was obtained between the measured and calculated properties of the 21.47-MeV stretched resonance in 13C, demonstrating the high-quality and precision of the GSM wave function calculations, which include coupling to the resonant and non-resonant particle continuum.
Published: 2022
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2. Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

Author: I. Stefan, B. Fornal, S. Leoni, F. Azaiez, C. Portail, J.C. Thomas, A.V. Karpov, D. Ackermann, P. Bednarczyk, Y. Blumenfeld, S. Calinescu, A. Chbihi, M. Ciemala, N. Cieplicka-Oryńczak, F.C.L. Crespi, S. Franchoo, F. Hammache, Ł.W. Iskra, B. Jacquot, R.V.F. Janssens, O. Kamalou, T. Lauritsen, M. Lewitowicz, L. Olivier, S.M. Lukyanov, M. Maccormick, A. Maj, P. Marini, I. Matea, M.A. Naumenko, F. de Oliveira Santos, C. Petrone, Yu.E. Penionzhkevich, F. Rotaru, H. Savajols, O. Sorlin, M. Stanoiu, B. Szpak, O.B. Tarasov, and D. Verney
Subjects: Physics, QC1-999
Abstract: Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example. Keywords: Nuclear reactions, Deep-inelastic collisions, Exotic nuclei
Published: 2018
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3. Unexpected high-energy γ emission from decaying exotic nuclei

Author: A. Gottardo, D. Verney, I. Deloncle, S. Péru, C. Delafosse, S. Roccia, I. Matea, C. Sotty, C. Andreoiu, C. Costache, M.-C. Delattre, A. Etilé, S. Franchoo, C. Gaulard, J. Guillot, F. Ibrahim, M. Lebois, M. MacCormick, N. Marginean, R. Marginean, M. Martini, C. Mihai, I. Mitu, L. Olivier, C. Portail, L. Qi, B. Roussière, L. Stan, D. Testov, J. Wilson, and D.T. Yordanov
Subjects: Physics, QC1-999
Abstract: The N=52 Ga83 β decay was studied at ALTO. The radioactive 83Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ-ray emission following β decay. While β-delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ-ray yield of 16(4)% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β-decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.
Published: 2017
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4. First spectroscopic study of odd-odd Cu78

Author: L. G. Pedersen, E. Sahin, A. Görgen, F. L. Bello Garrote, Y. Tsunoda, T. Otsuka, M. Niikura, S. Nishimura, Z. Xu, H. Baba, G. Benzoni, F. Browne, A. M. Bruce, S. Ceruti, F. C. L. Crespi, R. Daido, G. de Angelis, M.-C. Delattre, Zs. Dombradi, P. Doornenbal, Y. Fang, S. Franchoo, G. Gey, A. Gottardo, T. Isobe, P. R. John, H. S. Jung, I. Kojouharov, T. Kubo, N. Kurz, I. Kuti, Z. Li, G. Lorusso, I. Matea, K. Matsui, D. Mengoni, T. Miyazaki, V. Modamio, S. Momiyama, A. I. Morales, P. Morfouace, D. R. Napoli, F. Naqvi, H. Nishibata, A. Odahara, R. Orlandi, Z. Patel, S. Rice, H. Sakurai, H. Schaffner, L. Sinclair, P.-A. Söderström, D. Sohler, I. G. Stefan, T. Sumikama, D. Suzuki, R. Taniuchi, J. Taprogge, Z. Vajta, J. J. Valiente-Dobón, H. Watanabe, V. Werner, J. Wu, A. Yagi, M. Yalcinkaya, R. Yokoyama, and K. Yoshinaga
Published: 2023

5. Evolution of single-particle strength in neutron-rich 71Cu

Author: P. Morfouace, S. Franchoo, K. Sieja, I. Matea, L. Nalpas, M. Niikura, A.M. Sánchez-Benítez, I. Stefan, M. Assié, F. Azaiez, D. Beaumel, S. Boissinot, C. Borcea, R. Borcea, G. Burgunder, L. Cáceres, N. De Séréville, Zs. Dombrádi, J. Elseviers, B. Fernández-Domínguez, A. Gillibert, S. Giron, S. Grévy, F. Hammache, O. Kamalou, V. Lapoux, L. Lefebvre, A. Lepailleur, C. Louchart, G. Marquinez-Duran, I. Martel, A. Matta, D. Mengoni, D.R. Napoli, F. Recchia, J.-A. Scarpaci, D. Sohler, O. Sorlin, M. Stanoiu, C. Stodel, J.-C. Thomas, and Zs. Vajta
Subjects: Physics, QC1-999
Abstract: The strength functions of the πf5/2, πp3/2 and πf7/2 orbitals in neutron-rich 71Cu were obtained in a 72Zn(d,3He)71Cu proton pick-up reaction in inverse kinematics using a radioactive beam of 72Zn at 38 MeV/u. A dedicated set-up was developed to overcome the experimental challenges posed by the low cross section of the reaction and the low energy of the outgoing 3He particles. The excitation-energy spectrum was reconstructed and spectroscopic factors were obtained after analysis of the angular distributions with the finite-range Distorted-Wave Born Approximation (DWBA). The results show that unlike for the πf5/2 orbital and contrary to earlier interpretation, the πf7/2 single-particle strength distribution is not appreciably affected by the addition of neutrons beyond N=40.
Published: 2015
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6. M4 Resonances in Light Nuclei Studied at CCB

Author: N. Cieplicka-Oryńczak, B. Fornal, M. Ciemała, M. Kmiecik, A. Maj, J. Łukasik, P. Pawłowski, B. Sowicki, B. Wasilewska, M. Ziębliński, P. Bednarczyk, I. Ciepał, K. Dhanmeher, J. Grębosz, Ł.W. Iskra, M. Krzysiek, M. Matejska-Minda, K. Mazurek, W. Parol, B. Włoch, C. Boiano, S. Brambilla, B. Million, Y. Jaganathen, M. Płoszajczak, I. Burducea, C. Clisu, N. Florea, D.A. Iancu, N. Marginean, R. Marginean, L. Stan, M.N. Harakeh, P. Kulessa, I. Matea, M. Sferrazza, 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), 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: [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], General Physics and Astronomy
Abstract: International audience; M4 resonances in light nuclei result from the p3/2 → d5/2 stretched excitations. Their configurations should be relatively simple, which makes them good benchmarks for the theoretical calculations taking into account the role of continuum couplings. The first experimental studies aiming at tracing the decay of the M4 stretched resonance in 13C, located at 21.47 MeV, were undertaken at the Cyclotron Centre Bronowice at the Institute of Nuclear Physics Polish Academy of Sciences in Kraków, Poland (IFJ PAN). They provided information on the proton and neutron decay channels of this resonance to 12B and 12C daughter nuclei, respectively. These experimental results were then compared with the theoretical calculations based on the Gamow Shell Model approach, in terms of energy, width, and in particular, the decay pattern. Furthermore, the studies of the next cases, namely, 14N and 16O, where several M4 resonances appear at around 20 MeV, have been recently performed at CCB. The new experimental findings will serve as a testing ground for future calculations describing the heavier nuclei in this important region of the nuclear chart.
Published: 2022

7. New narrow resonances observed in the unbound nucleus F15

Author: V. Girard-Alcindor, A. Mercenne, I. Stefan, F. de Oliveira Santos, N. Michel, M. Płoszajczak, M. Assié, A. Lemasson, E. Clément, F. Flavigny, A. Matta, D. Ramos, M. Rejmund, J. Dudouet, D. Ackermann, P. Adsley, M. Assunção, B. Bastin, D. Beaumel, G. Benzoni, R. Borcea, A. J. Boston, D. Brugnara, L. Cáceres, B. Cederwall, I. Celikovic, V. Chudoba, M. Ciemala, J. Collado, F. C. L. Crespi, G. D'Agata, G. De France, F. Delaunay, C. Diget, C. Domingo-Pardo, J. Eberth, C. Fougères, S. Franchoo, F. Galtarossa, A. Georgiadou, J. Gibelin, S. Giraud, V. González, N. Goyal, A. Gottardo, J. Goupil, S. Grévy, V. Guimaraes, F. Hammache, L. J. Harkness-Brennan, H. Hess, N. Jovančević, D. S. Judson Oliver, O. Kamalou, A. Kamenyero, J. Kiener, W. Korten, S. Koyama, M. Labiche, L. Lalanne, V. Lapoux, S. Leblond, A. Lefevre, C. Lenain, S. Leoni, H. Li, A. Lopez-Martens, A. Maj, I. Matea, R. Menegazzo, D. Mengoni, A. Meyer, B. Million, B. Monteagudo, P. Morfouace, J. Mrazek, M. Niikura, J. Piot, Zs. Podolyak, C. Portail, A. Pullia, B. Quintana, F. Recchia, P. Reiter, K. Rezynkina, T. Roger, J. S. Rojo, F. Rotaru, M. D. Salsac, A. M. Sánchez Benítez, E. Sanchis, M. Şenyigit, N. de Séréville, M. Siciliano, J. Simpson, D. Sohler, O. Sorlin, M. Stanoiu, C. Stodel, D. Suzuki, C. Theisen, D. Thisse, J. C.Thomas, P. Ujic, J. J. Valiente-Dobón, and M. Zielińska
Published: 2022

8. Spectroscopy of neutron-rich nitrogen isotopes with Agata+Paris+Vamos

Author: S. Ziliani, M. Ciemała, F.C.L. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S.M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D.R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Ziębliński, M. Zielińska, Ziliani, S., Ciemała, M., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clément, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, Ł. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Müller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., 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 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), 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), Institut Laue-Langevin (ILL), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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), ILL, and Research unit Nuclear & Hadron Physics
Subjects: Physics, education.field_of_study, Spectrometer, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Population, Gamma ray, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Excited state, 0103 physical sciences, Neutron, AGATA, 010306 general physics, Spectroscopy, education, Beam (structure)
Abstract: Excited states of 17N, 18N and 19N were investigated through the measurement of gamma rays, following their population via deep-inelastic reactions induced by an 18O beam (7 MeV/u) on a thick 181Ta target. The experimental setup comprised the AGATA+PARIS detection system, coupled to the VAMOS++ magnetic spectrometer. In the 17N nucleus, the analysis of gamma-ray transitions de-exciting two states around 4-5 MeV clearly pointed to discrepancies with the lifetime values reported in literature. Three new gamma rays were observed in 18N at the energies of 1662.3 (3) keV, 2073.4 (8) keV and 2300.9 (8) keV, and hints for other two new transitions around 1566 keV and 1720 keV were found. In addition, a new transition with energy of 2489.7 (8) keV was observed in 19N.
Published: 2020

9. β-delayed neutron spectroscopy of 85As with MONSTER

Author: A. Pérez de Rada, D. Cano-Ott, T. Martínez, V. Alcayne, E. Mendoza, J. Plaza, A. Sanchez-Caballero, D. Villamarín, J. Äystö, A. Jokinen, A. Kankainen, H. Penttilä, S. Rinta-Antila, J. Agramunt, A. Algora, C. Domingo-Pardo, J. Lerendegui-Marco, J.L. Taín, K. Banerjee, C. Bhattacharya, P. Roy, F. Calviño, G. Cortés, C. Delafosse, I. Matea, J. Benito, S. Alhomaidhi, and A.K. Mistry
Subjects: General Medicine
Abstract: The β-delayed neutron emission in the 85As β-decay has been measured at the IGISOL facility of the Accelerator Laboratory of the University of Jyväskylä (JYFL). The complete β-decay has been studied with a setup which consists of a plastic scintillator, the MOdular Neutron time-of-flight SpectromeTER (MONSTER), and two types of γ-rays detectors (HPGe and LaBr3). The, β-delayed neutron energy distribution has been determined by unfolding the TOF spectrum with the iterative Bayesian unfolding method.
Published: 2023

10. Experimental Level Scheme of $^{78}$Cu

Author: L.G. Pedersen, E. Sahin, A. Görgen, F.L. Bello Garrote, Y. Tsunoda, T. Otsuka, M. Niikura, S. Nishimura, Z. Xu, H. Baba, G. Benzoni, F. Browne, A.M. Bruce, S. Ceruti, F.C.L. Crespi, R. Daido, G. de Angelis, M.-C. Delattre, Zs. Dombradi, P. Doornenbal, Y. Fang, S. Franchoo, G. Gey, A. Gottardo, T. Isobe, P.R. John, H.S. Jung, I. Kojouharov, T. Kubo, N. Kurz, I. Kuti, Z. Li, G. Lorusso, I. Matea, K. Matsui, D. Mengoni, T. Miyazaki, V. Modamio, S. Momiyama, A.I. Morales, P. Morfouace, D.R. Napoli, F. Naqvi, H. Nishibata, A. Odahara, R. Orlandi, Z. Patel, S. Rice, H. Sakurai, H. Schaffner, L. Sinclair, P.-A. Söderström, D. Sohler, I.G. Stefan, T. Sumikama, D. Suzuki, R. Taniuchi, J. Taprogge, Z. Vajta, J.J. Valiente-Dobón, H. Watanabe, V. Werner, J. Wu, A. Yagi, M. Yalcinkaya, R. Yokoyama, and K. Yoshinaga
Subjects: General Physics and Astronomy
Published: 2023

11. Feeding of the Residual States with GDR gamma Decay Studied by nuBall Coupled with PARIS

Author: M. Ciemała, M. Kmiecik, A. Maj, B. Fornal, P. Bednarczyk, N. Cieplicka-Oryńczak, Ł.W. Iskra, M. Matejska-Minda, K. Mazurek, B. Wasilewska, M. Ziębliński, F.C.L. Crespi, A. Bracco, S. Bottoni, F. Camera, S. Leoni, G. Benzoni, B. Million, O. Wieland, S. Brambilla, J. Wilson, I. Matea, M. Lebois, N. Jovančević, O. Dorvaux, Ch. Schmitt, J. Dudek, S. Kihel, P.J. Napiorkowski, M. Kicińska-Habior, I. Mazumdar, and V. Nanal
Subjects: General Physics and Astronomy
Published: 2023

12. Beta Decay of $^{82}$Ga Studied at the ALTO Facility

Author: L. Al Ayoubi, I. Matea, A. Kankainen, D. Verney, H. Al Falou, G. Benzoni, V. Bozkurt, M. Ciemala, C. Delafosse, I. Deloncle, F. DidierJean, M. Fallot, C. Gaular, A. Gottardo, V. Guadilla, J. Guillot, K. Hadyńska-Klęk, F. Ibrahim, N. Jovancevic, F. Le Blanc, M. Lebois, R. Li, T. Martínez, P. Napiorkowski, B. Roussiere, Yu.G. Sobolev, B. Sowicki, I. Stefan, S. Stukalov, D. Thisse, and G. Tocabens
Subjects: General Physics and Astronomy
Published: 2023

13. Complete set of bound negative-parity states in the neutron-rich nucleus 18N

Author: S. Ziliani, M. Ciemała, F. C. L. Crespi, S. Leoni, B. Fornal, T. Suzuki, T. Otsuka, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M. N. Harakeh, Ł. W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S. M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D. R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Ziębliński, M. Zielińska, 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 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), Institut Laue-Langevin (ILL), ILL, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay
Subjects: Set (abstract data type), Physics, Particle physics, medicine.anatomical_structure, 010308 nuclear & particles physics, 0103 physical sciences, medicine, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Parity (mathematics), 01 natural sciences, Nucleus
Abstract: International audience; High-resolution γ-ray spectroscopy of N18 is performed with the Advanced GAmma Tracking Array, following deep-inelastic processes induced by an O18 beam on a Ta181 target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in N18 below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 01− and 12− excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions and help to simultaneously reproduce the ground and first-excited states in N16 and N18, for the first time. Understanding the N18 structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.
Published: 2021

14. Coulomb and nuclear excitations of Zn70 and Ni68 at intermediate energy

Author: G. de Angelis, J. Mrazek, L. Perrot, R. Borcea, R. Astabatyan, F. Carstoiu, H. Guerin, M. Stanoiu, T. Roger, S. Grévy, L. Stuhl, C. Petrone, Zs. Podolyák, M. N. Harakeh, A. Lepailleur, J. C. Thomas, L. Cáceres, D. D. Dao, I. Stefan, F. Negoita, M. Krzysiek, A. Gottardo, V. Maslov, S. Bagchi, C. Borcea, Dóra Sohler, I. Matea, O. Wieland, Z. Vajta, F. Nowacki, M. Vandebrouck, P. Morfouace, F. Rotaru, S. Lukyanov, I. Kuti, O. Sorlin, Megumi Niikura, S. Franchoo, A. Krasznahorkay, K. Mazurek, Y. Penionzhkevich, M. Ciemála, A. Maj, Zsolt Dombrádi, C. Rigollet, M. Kmiecik, I. M. Harca, Eric Clément, O. Kamalou, S. Calinescu, and L. Olivier
Subjects: Physics, Proton, 010308 nuclear & particles physics, Prolate spheroid, 01 natural sciences, Spectral line, Intermediate energy, 0103 physical sciences, Oblate spheroid, Coulomb, Atomic physics, 010306 general physics, Beam energy, Excitation
Abstract: The reduced transition probabilities B ( E 2 ; 0 g.s. + → 2 1 + , 2 2 + ) in Zn 70 and the full B ( E 2 ; 0 g.s. + → 2 + ) strength up to S n = 7.79 MeV in Ni 68 have been determined at the LISE/GANIL facility using the Coulomb-excitation technique at intermediate beam energy on a Pb 208 target. The γ rays emitted in-flight were detected with an array of 46 BaF 2 crystals. The angles of the deflected nuclei were determined in order to disentangle and extract the Coulomb and nuclear contributions to the excitation of the 2 + states. The measured B ( E 2 ; 0 g.s. + → 2 1 + ) of 1432(124) e 2 fm 4 for Zn 70 falls in the lower part of the published values which clustered either around 1600 or above 2000 e 2 fm 4 , while the B ( E 2 ; 0 g.s. + → 2 2 + ) of 53(7) e 2 fm 4 agrees very well with the two published values. The relatively low B ( E 2 ; 0 g.s. + → 2 1 + ) of 301(38) e 2 fm 4 for Ni 68 agrees with previous studies and confirms a local magicity at Z = 28 , N = 40 . Combining the results of the low-energy spectra of Ni 68 and Zn 70 and their shell-model interpretations, it is interesting to notice that four different shapes (spherical, oblate, prolate, and triaxial) are present. Finally, a summed E 2 strength of only about 150 e 2 fm 4 has been found experimentally at high excitation energy, likely due to proton excitations across the Z = 28 gap. The experimental distribution of this high-energy E 2 excitation agrees with shell-model calculations, but its strength is about two times weaker.
Published: 2021

15. Persistence of the Z=28 shell gap in A=75 isobars: Identification of a possible (1/2−) μs isomer in Co75 and β decay to Ni75

Author: Hiroki Nishibata, A. I. Morales, Hirofumi Watanabe, Shin-Ichiro Nishimura, Megumi Niikura, Daisuke Suzuki, H. S. Jung, V. Werner, Ryo Taniuchi, D. Sohler, D. R. Napoli, Jan Taprogge, T. Isobe, N. Kurz, I. Kojouharov, Toshiyuki Sumikama, Jinguang Wu, P. A. Söderström, Ayumi Yagi, I. Matea, P. Morfouace, P. R. John, S. Franchoo, Shigeru Kubono, S. Escrig, F. Naqvi, Alfredo Poves, Atsuko Odahara, K. Matsui, Giuseppe Lorusso, H. Baba, Hiroyoshi Sakurai, Zhengyu Xu, Z. H. Li, E. Sahin, P. Doornenbal, D. Mengoni, Zs. Vajta, H. Schaffner, K. Yoshinaga, I. Stefan, F. Browne, and Guillaume Gey
Subjects: Physics, Proton, 010308 nuclear & particles physics, Center (category theory), Nuclear structure, Nuclear isomer, 7. Clean energy, 01 natural sciences, Spectral line, Nuclear physics, Nucleosynthesis, Excited state, 0103 physical sciences, Isobar, 010306 general physics
Abstract: Background: The evolution of shell structure around doubly-magic exotic nuclei is of great interest in nuclear physics and astrophysics. In the `south-west' region of $^{78}$Ni, the development of deformation might trigger a major shift in our understanding of explosive nucleosynthesis. To this end, new spectroscopic information on key close-lying nuclei is very valuable. Purpose: We intend to measure the isomeric and $\beta$ decay of $^{75}$Co, with one proton- and two neutron-holes relative to $^{78}$Ni, to access new nuclear structure information in $^{75}$Co and its $\beta$-decay daughters $^{75}$Ni and $^{74}$Ni. Methods: The nucleus $^{75}$Co is produced in relativistic in-flight fission reactions of $^{238}$U at the Radioactive Ion Beam Factory (RIBF) in the RIKEN Nishina Center. Its isomeric and $\beta$ decay are studied exploiting the BigRIPS and EURICA setups. Results: We obtain partial $\beta$-decay spectra for $^{75}$Ni and $^{74}$Ni, and report a new isomeric transition in $^{75}$Co. The energy ($E_{\gamma}=1914(2)$ keV) and half-life ($t_{1/2}=13(6)$ $\mu$s) of the delayed $\gamma$ ray lend support for the existence of a $J^{\pi}=(1/2^-)$ isomeric state at 1914(2) keV. A comparison with PFSDG-U shell-model calculations provides good account for the observed states in $^{75}$Ni, but the first calculated $1/2^-$ level in $^{75}$Co, a prolate $K=1/2$ state, is predicted about 1 MeV below the observed $(1/2^-)$ level. Conclusions: The spherical-like structure of the lowest-lying excited states in $^{75}$Ni is proved. In the case of $^{75}$Co, the results suggest that the dominance of the spherical configurations over the deformed ones might be stronger than expected below $^{78}$Ni. Further experimental efforts to discern the nature of the $J^{\pi}=(1/2^-)$ isomer are necessary.
Published: 2021

16. Accessing tens-to-hundreds femtoseconds nuclear state lifetimes with low-energy binary heavy-ion reactions

Author: M. Zieblinski, J. Grebosz, K. Mazurek, Simone Coelli, S. Brambilla, H. J. Li, B. Million, M. Rejmund, Bertrand Jacquot, P. Bednarczyk, N. Cieplicka-Oryńczak, M. Ciemala, M. Bast, S. Ziliani, O. Dorvaux, S. Erturk, Eric Clément, Ł. W. Iskra, C. Fransen, S. M. Lenzi, B. Fornal, P. J. Napiorkowski, C. Müller-Gatermann, M. Zielińska, B. Wasilewska, I. Matea, A. Maj, M. Kmiecik, Y. H. Kim, M. Kicińska-Habior, C. Michelagnoli, I. Stefan, M. Beckers, F. C. L. Crespi, O. Wieland, M. Lewitowicz, R. Palit, D. R. Napoli, Ch. Schmitt, A. V. Karpov, M. Stanoiu, F. Camera, Emanuele Vardaci, M. Matejska-Minda, A. Bracco, G. Benzoni, S. Bottoni, S. Leoni, V. Nanal, C. Boiano, A. Lemasson, Mohsen Harakeh, Thomas Braunroth, A. Goldkuhle, 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 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), Institut Laue-Langevin (ILL), ILL, 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 de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y. -H., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., H. Niewodniczanski Institute of Nuclear Physics, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Dipartimento di Fisica (Milano), Università degli Studi di Milano [Milano] (UNIMI), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Institut für Kernphysik der Universität zu Köln, Universität zu Köln, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Milano = University of Milan (UNIMI), Universität zu Köln = University of Cologne, 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), 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 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 Nuclear Energy
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Monte Carlo method, Hadron, FOS: Physical sciences, Binary number, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Excited state, 0103 physical sciences, Nuclear fusion, AGATA, Nuclear Experiment (nucl-ex), Connection (algebraic framework), Atomic physics, Nuclear Experiment, 010306 general physics
Abstract: A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range in products of low-energy heavy-ion binary reactions, with complex velocity distributions. The method is based on a detailed study of Doppler-broadened $$\gamma $$ γ -ray lineshapes. Its relevance is demonstrated in connection with the $$^{18}\text {O}(7.0\, \text {MeV/u})+\,^{181}\text {Ta}$$ 18 O ( 7.0 MeV/u ) + 181 Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in $$^{17}\text {O}$$ 17 O and $$^{19}\text {O}$$ 19 O , with known lifetimes, are used to validate the method over the $$\sim 20{-}400\,\text {fs}$$ ∼ 20 - 400 fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by $$\gamma $$ γ -tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.
Published: 2021

17. High-spin states in S35

Author: Shoji Nakamura, Yosuke Toh, K. Kisamori, Yuichi Hatsukawa, F. Azaiez, Yutaka Utsuno, I. Matea, Shin'ichiro Michimasa, Megumi Niikura, Ayumi Yagi, Mitsuo Koizumi, Rin Yokoyama, Hideo Harada, M. Sugawara, Daisuke Suzuki, Motoki Kobayashi, Nori Aoi, Kazuyoshi Furutaka, Noritaka Shimizu, D. Verney, Hiroki Nishibata, Hiroyuki Miya, Susumu Shimoura, T. Shizuma, Eiji Ideguchi, Motonobu Takaki, Shintaro Go, A. Kimura, and Fumito Kitatani
Subjects: Physics, Spin states, Condensed matter physics, 010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences
Published: 2021

18. 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

19. Charged-particle branching ratios above the neutron threshold in F19 : Constraining N15 production in core-collapse supernovae

Author: I. Matea, A. Gottardo, I. Sivacek, Mahmoud Mahgoub, M. Assié, S. Gillespie, L. Olivier, F. Hammache, M. Degerlier, V. Alcindor, I. Stefan, C. Delafosse, Didier Beaumel, A. Georgiadou, Jérôme Guillot, R. Garg, Marin Chabot, J. Riley, T. Faestermann, Alison Laird, L. Perrot, Valdir Guimaraes, F. Flavigny, Ralf Hertenberger, J. Kiener, P. Adsley, A. Lefebvre-Schuhl, N. de Sereville, Vincent Tatischeff, H.-F. Wirth, Arnd Meyer, and S. P. Fox
Subjects: Physics, 010308 nuclear & particles physics, Inelastic scattering, Branching (polymer chemistry), 01 natural sciences, Charged particle, Nuclear physics, Supernova, Nucleosynthesis, Excited state, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Ground state
Abstract: Spatially-correlated overabundances of $^{15}$N and $^{18}$O observed in some low-density graphite meteoritic grains have been connected to nucleosynthesis taking place in the helium-burning shell during core-collapse supernovae. Two of the reactions which have been identified as important to the final abundances of $^{15}$N and $^{18}$O are $^{18}$F($n,\alpha$)$^{15}$N and $^{18}$F($n,p$)$^{18}$O. The relative strengths of the $^{18}$F($n,\alpha$)$^{15}$N and $^{18}$F($n,p$)$^{18}$O reactions depend on the relative $\alpha_0$ and $p_0$ decays from states above the neutron threshold in $^{19}$F in addition to other properties. Experimental data on the charged-particle decays from these highly excited states are lacking or inconsistent. Two experiments were performed using proton inelastic scattering from LiF targets and magnetic spectrographs. The first experiment used the high-resolution Q3D spectrograph at Munich to constrain properties of levels in $^{19}$F. A second experiment using the Orsay Split-Pole spectrograph and an array of silicon detectors was performed in order to measure the charged-particle decays of neutron-unbound levels in $^{19}$F. A number of levels in $^{19}$F have been identified along with their corresponding charged-particle decays. The first state above the neutron threshold which has an observed proton-decay branch to the ground state of $^{18}$O lies 68 keV above the neutron threshold while the $\alpha$-particle decays from the neutron-unbound levels are generally observed to be much stronger than the proton decays. Neutron-unbound levels in $^{19}$F are observed to decay predominantly by $\alpha$-particle emission, supporting the role of $^{18}$F($n,\alpha$)$^{15}$N in the production of $^{15}$N in the helium-burning shell of supernovae. Improved resonant-scattering reaction data are required in order to be able to determine the reaction rates accurately.
Published: 2021

20. 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

21. Study of $$^{123}$$Ag $$\beta $$-decay at ALTO

Author: I. Matea, D. Susuki, E. A. Sokol, D. Verney, M. Lebois, Jh. Wilson, Yu. E. Penionzhkevich, N. N. Arsenyev, B. Roussière, I. Stefan, V. Smirnov, A. P. Severyukhin, F. Ibrahim, D. A. Testov, Joint Institute for Nuclear Research (JINR), 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), and The National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) [Moscow, Russia]
Subjects: inorganic chemicals, Nuclear and High Energy Physics, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], β-delayed neutron emission, 01 natural sciences, Nuclear physics, beams of radioactive nuclei, 0103 physical sciences, medicine, Nuclear fusion, Neutron, Beta (velocity), 010306 general physics, Physics, integumentary system, 010308 nuclear & particles physics, β-decay, technology, industry, and agriculture, Photofission, Beta decay, medicine.anatomical_structure, biological sciences, lipids (amino acids, peptides, and proteins), Nucleus, Delayed neutron
Abstract: The neutron rich $$^{123}$$ Ag nucleus was populated via induced photofission of UC $$_x$$ at the ALTO ISOL facility. Its $$\beta $$ -decay properties were studied by means of detecting $$\beta $$ -delayed $$\gamma $$ and neutron activities. The measured half-life T $$_{1/2}$$ = 0.350(20) s agreed with the earlier data; the $$\beta $$ -delayed neutron emission branching P $$_{1n}$$ = 1.01(24)% was reestablished using $$\gamma $$ and neutron counting.
Published: 2021

22. Coulomb and nuclear excitations of Zn 70 and Ni 68 at intermediate energy

Author: S. Calinescu, O. Sorlin, I. Matea, F. Carstoiu, D. D. Dao, F. Nowacki, G. de Angelis, R. Astabatyan, S. Bagchi, C. Borcea, R. Borcea, L. Cáceres, M. Ciemála, E. Clément, Z. Dombrádi, S. Franchoo, A. Gottardo, S. Grévy, H. Guerin, M. N. Harakeh, I. M. Harca, O. Kamalou, M. Kmiecik, A. Krasznahorkay, M. Krzysiek, I. Kuti, A. Lepailleur, S. Lukyanov, A. Maj, V. Maslov, K. Mazurek, P. Morfouace
Published: 2021
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23. Probing nuclear forces beyond the nuclear drip line: the cases of $^{16}$F and $^{15}$F: A Tribute to Mahir Hussein

Author: L. Caceres, A.M. Sánchez Benítez, Igor T. Čeliković, A. Matta, D. Verney, F. Rotaru, Valdir Guimaraes, P. Adsley, O. Sorlin, J. Guillot, T. Roger, C. Portail, V. Girard-Alcindor, I. Matea, A. Georgiadou, C. Petrone, D. Pantelica, R. Borcea, D. Suzuki, O. Kamalou, V. Lapoux, Megumi Niikura, I. Stefan, J. Piot, F. Flavigny, G. D’Agata, F. de Oliveira Santos, M. Ciemala, V. Tatischeff, V. Chudoba, L. Lalanne, C. Stodel, J. C. Thomas, N. Goyal, M. Stanoiu, C. Fougeres, S. Grévy, F. Negoita, N. de Séréville, L. Perrot, G. Dumitru, M. Assie, A. Meyer, J. C. Angelique, Marlete Assunção, Nicolas Michel, F. Hammache, D. Beaumel, S. Franchoo, Predrag Ujić, Dieter Ackermann, Shoko Koyama, F. de Grancey, J. Kiener, E. Berthoumieux, P. Morfouace, J. Mrazek, K. Subotic, 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), 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)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Elastic scattering, Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Hadron, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Asymmetry, Excited state, 0103 physical sciences, Nuclear force, Mirror nuclei, Atomic physics, 010306 general physics, Wave function, Nuclear Experiment, media_common
Abstract: The unbound proton-rich nuclei $$^{16}$$ F and $$^{15}$$ F are investigated experimentally and theoretically. Several experiments using the resonant elastic scattering method were performed at GANIL with radioactive beams to determine the properties of the low lying states of these nuclei. Strong asymmetry between $$^{16}$$ F– $$^{16}$$ N and $$^{15}$$ F– $$^{15}$$ C mirror nuclei is observed. The strength of the $$nucleon-nucleon$$ effective interaction involving the loosely bound proton in the $$s_{1/2}$$ orbit is significantly modified with respect to their mirror nuclei $$^{16}$$ N and $$^{15}$$ C. The reduction of the effective interaction is estimated by calculating the interaction energies with a schematic zero-range force. It is found that, after correcting for the effects due to changes in the radial distribution of the single-particle wave functions, the mirror symmetry of the $$n-p$$ interaction is preserved between $$^{16}$$ F and $$^{16}$$ N, while a difference of 63% is measured between the $$p-p$$ versus $$n-n$$ interactions in the second excited state of $$^{15}$$ F and $$^{15}$$ C nuclei. Several explanations are proposed.
Published: 2021

24. Detailed study of the decay of 32Ar

Author: M. J. G. Borge, F. de Oliveira Santos, B. Blank, A. Bey, N. Adimi, J. C. Thomas, K. Suemmerer, J. Giovinazzo, Ángel Perea, H. H. Knudsen, Carole Dossat, I. Matea, H. O. U. Fynbo, Olof Tengblad, M. Alcorta, M. Madurga, B. A. Brown, A. Magilligan, 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), 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), 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), 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), Région Nouvelle-Aquitaine, Consorcio de Universidades Mexicanas, and National Science Foundation (US)
Subjects: Physics, Nuclear and High Energy Physics, Decay scheme, Silicon, 010308 nuclear & particles physics, Detector, Nuclear Theory, Gamma ray, chemistry.chemical_element, FOS: Physical sciences, Germanium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Beta decay, Nuclear physics, chemistry, 0103 physical sciences, High Energy Physics::Experiment, Cube, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Fermi Gamma-ray Space Telescope
Abstract: 16 pags., 9 figs., 7 tabs., In an experiment performed at the SPIRAL1 facility of GANIL, the β decay of Ar has been studied by means of the “Silicon Cube” device associated with germanium clover detectors from the EXOGAM array. Beta-delayed protons and γ rays have been observed and allowed the determination of all relevant decay branches. The Gamow–Teller strength distribution is compared to shell-model calculations and excellent agreement is found. The Fermi strength is inline with expectations. A quasi-complete decay scheme of Ar is established., This work was partly funded by the Conseil régional de la Nouvelle Aquitaine and the EU through the Human Capital and Mobility program. We acknowledge support from CICYT via contract FPA2007-62179. BAB is supported by NSF via Grant PHY1811855.
Published: 2021
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25. 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

26. Using γ rays to disentangle fusion-fission and quasifission near the Coulomb barrier: A test of principle in the fusion-fission and quasielastic channels

Author: C. Petrone, C. Borcea, A. Maj, K. V. Novikov, G. N. Knyazheva, Emanuele Vardaci, V. V. Kirakosyan, A. Bracco, S. Brambilla, G. Sposito, D. Verney, I. M. Harca, D. Quero, K. Saveleva, John W. Wilson, A. Pulcini, S. Calinescu, I. V. Kolesov, M. Ciemala, O. Dorvaux, E. M. Kozulin, F. Camera, I. M. Itkis, O. Stezowski, M. Ashaduzzaman, B. de Canditiis, C. Schmitt, D. Pierroutsakou, A. Di Nitto, P. K. Rath, G. La Rana, C. Parascandolo, N. I. Kozulina, I. Matea, 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: [PHYS]Physics [physics], Physics, Nuclear reaction, Angular momentum, Photon, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Spectrometer, Mass distribution, 010308 nuclear & particles physics, Coulomb barrier, Observable, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Ion, Nuclear physics, 0103 physical sciences, Nuclear Reactions, Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; The overlap in the mass symmetric region of the reaction products from fusion-fission and quasifission complicates the assignment of symmetric events to complete fusion on the basis of the mass distribution alone. Additional observables, besides mass distribution, should be used. The approach proposed here relies on the fact that fusion-fission and quasifission are characterized by different timescales. Within this framework, we performed a detailed study to find out how timescales can be probed via angular momentum transfer as measured via γ-ray multiplicities. The proof of principle was carried out by measuring the γ rays in coincidence with fusion-fission and quasielastic binary fragments in the reaction S32 + Au197 at beam energy near the Coulomb barrier. The experiment was performed at the Accélérateur Linéaire Tandem à Orsay (ALTO) facility at the Institut De Physique Nucléaire (IPN) in Orsay (France) using a detection setup consisting of ORGAM (ORsay GAMma) and PARIS (Photon Array Radioactive Ion Stable beams) γ-detectors arrays coupled with the CORSET (CORrelation SETup) time-of-flight spectrometer. Results of the sensitivity of this method to distinguish reaction channels with different dynamics are discussed.
Published: 2020

27. Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2+ state in C16 and O20

Author: M. Ciemała, S. Ziliani, F. C. L. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M. N. Harakeh, Ł. W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S. M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D. R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Zieblinski, M. Zielińska, A. Ataç, D. Barrientos, B. Birkenbach, A. J. Boston, B. Cederwall, L. Charles, J. Collado, D. M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Dudouet, J. Eberth, V. González, J. Goupil, L. J. Harkness-Brennan, H. Hess, D. S. Judson, A. Jungclaus, W. Korten, M. Labiche, A. Lefevre, R. Menegazzo, D. Mengoni, J. Nyberg, R. M. Perez-Vidal, Zs. Podolyak, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, O. Stezowski, Ch. Theisen, J. J. Valiente-Dobón, J. D. Holt, J. Menéndez, A. Schwenk, and J. Simonis
Subjects: Physics, 010308 nuclear & particles physics, 0103 physical sciences, Nuclear structure, Ab initio, Neutron, State (functional analysis), Atomic physics, 010306 general physics, 7. Clean energy, 01 natural sciences, Nuclear theory
Abstract: To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2(+) state in neutron-rich O-20, tau(2(2)(+)) = 150(-30)(+80) fs, and an estimate for the lifetime of ...
Published: 2020

28. Potential of prompt $\gamma $-ray emission studies in fast-neutron induced fission: a first step

Author: Ali Al-Adili, I. Matea, G. Georgiev, Andreas Oberstedt, C. Schmitt, A. Göök, D. Choudhury, Fabio Zeiser, L. Qi, A. Chatillon, Angélique Gatera, Stephan Oberstedt, B. Wasilewska, S. J. Rose, J. N. Wilson, M. Lebois, B. Laurent, A. Maj, 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), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), 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), 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: [PHYS]Physics [physics], Physics, Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, Nuclear structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Spectral line, Nuclear physics, 0103 physical sciences, Neutron source, Nuclear fusion, Neutron, 010306 general physics, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS, Spontaneous fission
Abstract: International audience; Prompt $\gamma $-ray spectra emitted in fast-neutron induced fission of $^{239}$Pu have been recently measured by using the LICORNE directional neutron source at E$_n$ = 1.8 MeV. The results are used in parallel with the measurements of fast-neutron induced fission of $^{238}$U and spontaneous fission of $^{252}$Cf to assess the potential of such reactions and observables, in contributing to the understanding of fission. The $\gamma $-ray spectra were measured and analyzed under similar conditions, allowing a consistent and robust comparison between the three systems. They are further compared to Monte–Carlo simulations based on two widely-used semi-empirical codes, FREYA and GEF. Differences in the low and high energy portions of the spectrum are interpreted based on simple arguments involving nuclear structure and evaporation effects. The significance and potential of experimental campaigns of this kind, as well as current limitations, are highlighted, together with straightforward but mandatory extensions.
Published: 2020

29. Features of the Fission Fragments Formed in the Heavy Ion induced $^{32}\hbox {S}$+$^{197}\hbox {Au}$ reaction near the interaction barrier

Author: G. N. Knyazheva, Emanuele Vardaci, O. Dorvaux, P.K. Rath, D. Verney, E. M. Kozulin, B. Decanditiis, S. Brambilla, E. Saveleva, D. Quero, G. La Rana, J. N. Wilson, S. Calinescu, N. I. Kozulina, C. Schmitt, I. M. Itkis, F. Camera, A. Bracco, K. V. Novikov, W. H. Trzaska, O. Stezowski, I. Matea, A. Pulcini, I. M. Harca, A. Di Nitto, M. Ciemala, V. V. Kirakosyan, C. Petrone, M. Ashaduzzaman, I. V. Kolesov, C. Borcea, A. Maj, 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), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), SPS, PARIS, 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Kozulin, E. M., Harca, I. M., Vardaci, E., Matea, I., Maj, A., Itkis, I., Knyazheva, G., Novikov, K., Dorvaux, O., Ciemala, M., Brambilla, S., Kozulina, N., Kolesov, I. V., Saveleva, E., Kirakosyan, V. V., Schmitt, C., Borcea, C., Calinescu, S., Petrone, C., Ashaduzzaman, M., Decanditiis, B., Pulcini, A., Quero, D., Rath, P., di Nitto, A., La Rana, G., Bracco, A., Camera, F., Stezowski, O., Wilson, J., Verney, D., and Trzaska, W. H.
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Fission, Hadron, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Kinetic energy, 7. Clean energy, 01 natural sciences, Semi-empirical mass formula, Yield (chemistry), 0103 physical sciences, Physics::Atomic and Molecular Clusters, Nuclear fusion, Neutron, Atomic physics, 010306 general physics, Nuclear Experiment, Beam (structure)
Abstract: International audience; The features of fission fragments formed in the near barrier reaction $^{32}\hbox {S}$ + $^{197}\hbox {Au}$ ($E^\mathrm{lab}_\mathrm{beam}=166\,\hbox {MeV}$) are investigated. The measurement was performed at the ALTO facility of IPN Orsay, France, with the aim of clarifying the quantitative contribution of the quasi-fission process to the total fission events. The mass and total kinetic energy of the fission fragments were compared to the expectations of the liquid drop model, revealing an asymmetric fission component which may be traced back to a quasi-fission process mixed with the fusion–fission events. The $\gamma $-rays and neutrons measured in coincidence with the fission fragments were used to yield additional information for the discrimination of the two aforementioned mechanisms. All observed trends are consistent and fairly well reproduced by the statistical model.
Published: 2020

30. B(E2) anomalies in the yrast band of Os170

Author: A. Etile, Georgi Georgiev, L. Grente, J. Ljungvall, Tomás R. Rodríguez, S. Roccia, M. Klintefjord, A. Goasduff, I. Matea, M. D. Salsac, F. L. Bello Garrote, C. Sotty, A. Kusoglu, and F. Giacoppo
Subjects: Physics, 010308 nuclear & particles physics, Yrast, Nuclear structure, chemistry.chemical_element, Prolate spheroid, 01 natural sciences, 7. Clean energy, chemistry, Neutron number, Excited state, 0103 physical sciences, Osmium, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Energy (signal processing)
Abstract: Background: The neutron-deficient osmium isotopic chain provides a great laboratory for the study of shape evolution, with the transition from the soft triaxial rotor in $^{168}\mathrm{Os}$ to the well-deformed prolate rotor in $^{180}\mathrm{Os}$, while shape coexistence appears around $N=96$ in $^{172}\mathrm{Os}$. Therefore, the study of the Os isotopic chain should provide a better understanding of shape changes in nuclei and a detailed scrutiny of nuclear structure calculations. In this paper, the lifetimes of the low-lying yrast states of $^{170}\mathrm{Os}$ have been measured for the first time to investigate the shape evolution with neutron number.Purpose: Lifetimes of excited states in the ground-state band of $^{170}\mathrm{Os}$ are measured to investigate the shape evolution with neutron number in osmium isotopes and compare with state-of-the-art calculations.Methods: The states of interest were populated via the fusion-evaporation reaction $^{142}\mathrm{Nd}(^{32}\mathrm{S},4n)$ at a bombarding energy of 170 MeV at the ALTO facility from IPN (Orsay, France). Lifetimes of the ${2}_{1}^{+}$ and ${4}_{1}^{+}$ states in $^{170}\mathrm{Os}$ were measured with the recoil-distance Doppler-shift method using the Orsay universal plunger system.Results: Lifetimes of the two first excited states in $^{170}\mathrm{Os}$ were measured for the first time. A very small $B(E2;{4}_{1}^{+}\ensuremath{\rightarrow}{2}_{1}^{+})/B(E2;{2}_{1}^{+}\ensuremath{\rightarrow}{0}_{1}^{+})=0.38(11)$ was found, which is very uncharacteristic for collective nuclei. These results were compared to state-of-the-art beyond-mean-field calculations.Conclusions: Although theoretical results give satisfactory results for the energy of the first few excited states in $^{170}\mathrm{Os}$ and the $B(E2;{2}_{1}^{+}\ensuremath{\rightarrow}{0}_{1}^{+})$ they fail to reproduce the very small $B(E2;{4}_{1}^{+}\ensuremath{\rightarrow}{2}_{1}^{+})$, which remains a puzzle.
Published: 2019

31. $\gamma$-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

32. Spectroscopy of Neutron Induced Reactions with the $\nu $-ball Spectrometer

Author: S. Bottoni, M. Lebois, L. Qi, D. Reygadas Tello, R. Shearman, I. Homm, R. B. Gerst, J. N. Wilson, T. Kröll, D. Verney, A. Boso, A. Oberstedt, I. Matea, P. Koseoglou, P. A. Söderström, M. Babo, G. Häfner, M. Piersa, D. Thisse, B. Fornal, M. Rudigier, V. Sanchez, J. Wiederhold, C. Henrich, P. H. Regan, A. Lopez-Martens, F. Ibrahim, K. Miernik, J. Ljungvall, N. Cieplicka-Oryńczak, M. Diakaki, P. Inavov, A. Algora, C. Delafosse, N. Warr, G. Tocabens, J. Benito Garcia, K. Belvedere, S. Leoni, Y. Popovitch, Muriel Fallot, J. Nemer, K. Rezynkina, W. Paulson, C. Sürder, M. Bunce, D. Gestvang, D. Knezevic, V. Guadilla-Gomez, K. Hauschild, Zs. Podolyák, L. Cortes, D. Ralet, A. Gottardo, A. Dragic, E. Adamska, G. Benzoni, R. Lozeva, R. Chakma, N. Jovančević, S. Oberstedt, R. Canavan, F. Adsley, P. Davies, M. Yavachova, C. Schmitt, M. Heine, Fabio Zeiser, D. Etasse, L. M. Fraile, T. Kurtukian-Nieto, A. Blazhev, L. Iskra, 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-Saclay, 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 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 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), 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), 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 - Faculté des Sciences et des Techniques, and 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)
Subjects: Physics, education.field_of_study, Spectrometer, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Population, Aucun, General Physics and Astronomy, Shields, chemistry.chemical_element, Germanium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, chemistry, 0103 physical sciences, Neutron source, Neutron, Atomic physics, 010306 general physics, education, Spectroscopy, Nuclear Experiment
Abstract: The ʋ-ball is a high-efficiency hybrid spectrometer which consists of both germanium (Ge) detectors and associated anti-Compton BGO shields, coupled to lanthanum bromide (LaBr3) detectors. The hybrid configuration provides a combination of both excellent energy and timing resolutions. The ʋ-ball geometry allows the coupling with the LICORNE directional neutron source at the ALTO facility of the IPN, Orsay. This opens the possibility to perform precise spectroscopy of neutron induced reactions and was used for two experiments during the recent experimental campaign. These two experiments are described here: 1. Spectroscopy of the neutron-rich fission fragments produced in the 238U(n; f) and 232Th(n; f) reactions; 2. Spectroscopy above the shape isomer in 238U. The 238U(n; f) and 232Th(n; f) reactions produce hundreds of neutron-rich nuclei on which gamma-ray spectroscopy can be performed. The main goal of the experiment aiming to populate the shape isomer in 238U is the measurement of the gamma-ray and fission decay branches as well as determination of level scheme in the super-deformed minimum. The shape isomer is populated by 238U(n; n') reaction, which gives a very advantageous population cross section over other reactions. More detailed descriptions of these two ʋ-ball experiments will be presented here.
Published: 2019

33. SPECTROSCOPY OF NEUTRON-RICH C, O, N AND F ISOTOPES WITH THE AGATA plus PARIS plus VAMOS SETUP AT GANIL

Author: S. Ziliani, M. Ciemała, F. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, O. Dorvaux, S. Erturk, G. De France, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, B. Million, C. Müller-Gatermann, P. Napiorkowski, V. Nanal, M. Matejska-Minda, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, B. Wasilewska, M. Ziębliński, Fornal, Bogdan -- 0000-0002-1142-8067, Ciemala, Michal -- 0000-0001-5328-720X, [Ziliani, S. -- Crespi, F. -- Leoni, S. -- Bracco, A. -- Bottoni, S. -- Camera, F.] Univ Milan, Milan, Italy -- [Ziliani, S. -- Crespi, F. -- Leoni, S. -- Benzoni, G. -- Bracco, A. -- Boiano, C. -- Bottoni, S. -- Brambilla, S. -- Camera, F. -- Million, B.] INFN, Sez Milano, Milan, Italy -- [Ciemala, M. -- Fornal, B. -- Maj, A. -- Bednarczyk, P. -- Cieplicka-Orynczak, N. -- Grebosz, J. -- Iskra, L. W. -- Kmiecik, M. -- Mazurek, K. -- Wasilewska, B.] Polish Acad Sci, Inst Nucl Phys, Krakow, Poland -- [Bast, M. -- Beckers, M. -- Braunroth, T. -- Goldkuhle, A. -- Mueller-Gatermann, C.] IKP Cologne, Cologne, Germany -- [Clement, E. -- De France, G. -- Jacquot, B. -- Kim, Y. -- Lemasson, A. -- Li, H. -- Rejmund, M.] CEA, DSAM, GANIL, Caen, France -- [Clement, E. -- De France, G. -- Jacquot, B. -- Kim, Y. -- Lemasson, A. -- Li, H. -- Rejmund, M.] CNRS, IN2P3, Caen, France -- [Dorvaux, O. -- Schmitt, Ch] CNRS, IN2P3, IPHC UMR 7178, Strasbourg, France -- [Erturk, S.] Nigde Univ, Nigde, Turkey -- [Harakeh, M. N.] KVI Ctr Adv Radiat Technol, Groningen, Netherlands -- [Kicinska-Habior, M. -- Matea, I -- Stefan, I] Warsaw Univ, Fac Phys, Warsaw, Poland -- [Kicinska-Habior, M. -- Matea, I -- Stefan, I] IPN, Orsay Lab, Orsay, France -- [Michelagnoli, C.] ILL Grenoble, Grenoble, France -- [Napiorkowski, P. -- Matejska-Minda, M.] Univ Warsaw, Heavy Ion Lab, Warsaw, Poland -- [Nanal, V] Dept Nucl & Atom Phys, Mumbai, Maharashtra, India -- [Stanoiu, M.] IFIN HH, Bucharest, Romania -- [Zieblinski, M.] CEA, DRF, IRFU, Ctr CEA Saclay, Saclay, France, 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 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), 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 Laue-Langevin (ILL), ILL, 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-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), 0-Belirlenecek, 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: Physics, Isotope, Spectrometer, 010308 nuclear & particles physics, General Physics and Astronomy, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 0-Belirlenecek, Nuclear physics, Nuclear interaction, Ab initio quantum chemistry methods, 0103 physical sciences, Neutron, AGATA, Spectroscopy, Nuclear Experiment
Abstract: Zakopane Conference on Nuclear Physics - Extremes of the Nuclear Landscape -- AUG 26-SEP 02, 2018 -- Zakopane, POLAND, WOS: 000463866500052, Recent ab initio calculations pointed out the importance of the three-body terms of the nuclear interaction, in the description of the structure of n-rich systems. The state lifetimes in light n-rich carbon and oxygen nuclei have been predicted to be sensitive to the three-body terms and, in this context, an experiment, aiming at the measurement of these lifetimes, was performed in GANIL in July 2017 with the AGATA and PARIS arrays coupled to the VAMOS++ magnetic spectrometer. Details on the AGATA preliminary data analysis are presented., National Science Centre, Poland (NCN) [2013/08/M/ST2/00257, 2014/14/M/ST2/00738, 2016/22/M/ST2/00269], This work was supported by the National Science Centre, Poland (NCN) under contracts No. 2013/08/M/ST2/00257, 2014/14/M/ST2/00738 and 2016/22/M/ST2/00269.
Published: 2019

34. Trial for the long neutron counter TETRA using $^{96,97}$Rb radioactive sources

Author: D. A. Testov, C. Delafosse, B. Roussière, D. Thisse, F. Ibrahim, I. Matea, A. P. Severyukhin, V. A. Maslov, R. Thoër, C. Gaulard, E. A. Sokol, V. Smirnov, Y. E. Penionzhkevich, F. Didierjean, Y. Sobolev, J. Guillot, A. Boso, G. Tocabens, F. Le Blanc, S. M. Lukyanov, D. Verney, I. Deloncle, 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), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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 Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, [PHYS]Physics [physics], biology, 010308 nuclear & particles physics, radioactive sources, Nuclear Theory, tutkimuslaitteet, Radiochemistry, biology.organism_classification, 01 natural sciences, 7. Clean energy, 0103 physical sciences, Tetra, Neutron, ydinfysiikka, 010306 general physics, Nuclear Experiment, Instrumentation, Mathematical Physics, long neutron counter
Abstract: International audience; The TETRA long neutron counter is operated at ALTO ISOL facility behind the PARRNe mass separator. TETRA has been proven to be a unique instrument for measurements of β-decay properties of short-lived neutron-rich nuclei having applications for the nuclear structure and/or astrophysical r-process calculations. A proper calibration of TETRA can allow validation of the experimental procedure used for determination of β-delayed one-neutron emission probabilities (P1n). It requires the use of a well-known β-neutron decaying radioactive source which can be only produced and measured on-line due to its short half-life. Thus, the present paper reports on measurements of P1n and T1/2 of 96,97Rb nuclei using TETRA . The results obtained are in a good agreement with the values available in the literature. This proves that the developed techniques can be applied to unknown P1n and T1/2 of neutron-rich species.
Published: 2019

35. Escape-suppression shield detector for the MINIBALL $\gamma$-ray spectrometer

Author: D. Rosiak, N. Warr, T. Nguyen Trung, R. Hirsch, A. Gottardo, J. Eberth, M. Seidlitz, C. Le Galliard, P. Reiter, Herbert Hess, I. Matea, T. Steinbach, 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), 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: Physics, Nuclear and High Energy Physics, Photomultiplier, Large Hadron Collider, Spectrometer, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Monte Carlo method, Detector, 01 natural sciences, Coincidence, Nuclear physics, Shield, 0103 physical sciences, Nuclear fusion, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Nuclear Experiment
Abstract: International audience; A bismuth-germanate (BGO) escape-suppression shield for the high-purity germanium triple-cluster detector of the MINIBALL $ \gamma$ -ray spectrometer was designed and built. Monte Carlo simulations with the simulation code GEANT4 were performed to guide the construction and to determine the detector geometry of the new BGO shield. After the first measurements concerning mechanical properties of the BGO housing and the performance of the photomultiplier tubes at the Institut de Physique Nucléaire, Orsay, the prototype BGO escape-suppression shield was combined with a MINIBALL triple-cluster detector at the Institut für Kernphysik, Cologne. A dedicated electronics and digital data-acquisition system was put into operation in order to determine timing properties of the combined coincidence measurement and to measure values for the energy resolution of the BGO detectors, for the BGO low-energy threshold, and for the crucial peak-to-total ratio (P/T). The measured P/T value for a standard$^{60}$Co $ \gamma$ -ray source compares well with expectations and will allow to proceed with the amendment of the MINIBALL triple-cluster detectors with an escape-suppression shield for improved in-beam $ \gamma$ -ray spectroscopy especially at the new HIE-ISOLDE accelerator for radioactive ion beams at CERN.
Published: 2019

36. Pseudospin Symmetry and Microscopic Origin of Shape Coexistence in the Ni78 Region: A Hint from Lifetime Measurements

Author: C. Delafosse, D. Verney, P. Marević, A. Gottardo, C. Michelagnoli, A. Lemasson, A. Goasduff, J. Ljungvall, E. Clément, A. Korichi, G. De Angelis, C. Andreoiu, M. Babo, A. Boso, F. Didierjean, J. Dudouet, S. Franchoo, A. Gadea, G. Georgiev, F. Ibrahim, B. Jacquot, T. Konstantinopoulos, S. M. Lenzi, G. Maquart, I. Matea, D. Mengoni, D. R. Napoli, T. Nikšić, L. Olivier, R. M. Pérez-Vidal, C. Portail, F. Recchia, N. Redon, M. Siciliano, I. Stefan, O. Stezowski, D. Vretenar, M. Zielinska, D. Barrientos, G. Benzoni, B. Birkenbach, A. J. Boston, H. C. Boston, B. Cederwall, L. Charles, M. Ciemala, J. Collado, D. M. Cullen, P. Désesquelles, G. de France, C. Domingo-Pardo, J. Eberth, V. González, L. J. Harkness-Brennan, H. Hess, D. S. Judson, A. Jungclaus, W. Korten, A. Lefevre, F. Legruel, R. Menegazzo, B. Million, J. Nyberg, B. Quintana, D. Ralet, P. Reiter, F. Saillant, E. Sanchis, Ch. Theisen, and J. J. Valiente Dobon
Subjects: Physics, Valence (chemistry), Proton, 010308 nuclear & particles physics, General Physics and Astronomy, 01 natural sciences, Particle identification, Recoil, Excited state, 0103 physical sciences, Quadrupole, Neutron, AGATA, Atomic physics, 010306 general physics
Abstract: Lifetime measurements of excited states of the light N = 52 isotones 88 Kr , 86 Se , and 84 Ge have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B ( E 2 ; 2 + → 0 + ) and B ( E 2 ; 4 + → 2 + ) were obtained for the first time for the hard-to-reach 84 Ge . While the B ( E 2 ; 2 + → 0 + ) values of 88 Kr , 86 Se saturate the maximum quadrupole collectivity offered by the natural valence ( 3 s , 2 d , 1 g 7 / 2 , 1 h 11 / 2 ) space of an inert 78 Ni core, the value obtained for 84 Ge largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N ≲ 49 , extend beyond N = 50 . The onset of collectivity at Z = 32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector ρ field in shell-structure evolution.
Published: 2018

37. Fission and Quasi-Fission Dynamics Near the Coulomb Barrier: $\gamma$ Rays as Probe for their Timescale

Author: I. M. Itkis, C. Petrone, I. M. Harca, N. I. Kozulina, J. Wilson, P. K. Rath, A. Pulcini, B. de Canditiis, G. Sposito, O. Dorvaux, E. M. Kozulin, D. Quero, O. Stezowski, Wladyslaw Henryk Trzaska, C. Schmitt, I. V. Kolesov, A. Di Nitto, S. Calinescu, G. La Rana, F. Davide, S. Brambilla, E. Saveleva, F. Camera, M. Ashaduzzaman, V. V. Kirakosyan, A. Bracco, M. Ciemala, G. N. Knyazheva, S. N. Dmitriev, K. V. Novikov, Emanuele Vardaci, I. Matea, C. Borcea, A. Maj, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (INFN, Sezione di Napoli), Istituto Nazionale di Fisica Nucleare (INFN), Horia Hulubei National Institute of Physics and Nuclear Engineering (NIPNE), IFIN-HH, Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow, Poland, 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), 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), 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 de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Penionzhkevich, Yu E, Yu G Sobolev, Pulcini, A., Vardaci, E., Kozulin, E. M., Ashaduzzaman, M., Borcea, C., Bracco, A., Brambilla, S., Calinescu, S., Camera, F., Ciemala, M., Davide, F., de Canditiis, B., Di Nitto, A., Dmitriev, S., Dorvaux, O., Harca, I. M., Itkis, I. M., Kirakosyan, V. V., Knyazheva, G., Kozulina, N., Kolesov, I. V., La Rana, G., Maj, A., Matea, I., Novikov, K., Petrone, C., Quero, D., Rath, P. K., Saveleva, E., Schmitt, C., Sposito, G., Stezowski, O., Trzaska, W. H., Wilson, J., 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 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), 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), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Fission, Experiment-Nucl, Dynamics (mechanics), Theory-Nucl, Coulomb barrier, Atomic physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; The overlap in the mass symmetric region of the reaction products from fusion-fission and quasi-fission complicates the assignment of symmetric events to complete fusion on the basis of the mass distribution alone. Additional observables, besides mass distribution, should be used. The method proposed here relies on the fact that fusion-fission and quasifission are characterized by a different timescale. Within this framework we performed a detailed study to find out if timescales can be probed via angular momentum as measured via γ rays multiplicity. The proof of principle was carried out by measuring the γ rays in coincidence with two fragments in the reaction 32S + 197Au at beam energy near the Coulomb barrier. The experiment has been performed at the Tandem ALTO facility at IPN Orsay using a detection setup consisting of ORGAM and PARIS γ detector arrays coupled with the CORSET time-of-flight spectrometer. Preliminary results on the sensitivity of this method to distinguish reaction channels with different dynamics are discusses.
Published: 2018

38. Lifetime Measurements Using RDDS Method in the Vicinity of $^{78}$Ni

Author: S. M. Lenzi, F. Didierjean, D. Mengoni, G. Maquart, A. Goasduff, Georgi P. Georgiev, D. Verney, C. Michelagnoli, M. Babo, A. Gadea, A. Korichi, O. Stezowski, D. R. Napoli, Bertrand Jacquot, J. Ljungvall, J Dudouet, S. Franchoo, Emyr Clement, T. Konstantinopoulos, L. Olivier, R. M. Perez-Vidal, Corina Andreoiu, A. Boso, A. Gottardo, F. Ibrahim, A. Lemasson, C. Portail, C. Delafosse, F. Recchia, I. Matea, M. Zielińska, N. Redon, 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), 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), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-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, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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), 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Spectrometer, 010308 nuclear & particles physics, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Particle identification, Nuclear physics, symbols.namesake, Recoil, 0103 physical sciences, Quadrupole, symbols, AGATA, 010306 general physics, Doppler effect
Abstract: International audience; Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich N = 52 isotones 88Kr and 86Se were investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at GANIL (Caen, France) using the Orsay Universal Plunger System (OUPS) for the RDDS technique and the AGATA array for the γ-ray detection coupled to the VAMOS++ magnetic spectrometer for an event-by-event particle identification. In 88Kr, the lifetimes of seven levels were determined and in 86Se, the lifetimes of five levels were determined. The deduced B(E2; 2+ 1 → 0 + 1 ) are compared with mean-field and shellmodel calculations.
Published: 2018

39. Determination of Lifetimes of Excited States in Neutron-rich $^{20}$O Isotope from Experiment with the AGATA+PARIS+VAMOS Setup

Author: M. Ciemała, S. Ziliani, F. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, O. Dorvaux, S. Ertürk, G. De France, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, B. Millon, C. Müller-Gatermann, P. Napiorkowski, V. Nanal, M. Matejska-Minda, M. Rejmund, B. Sowicki, Ch. Schmitt, M. Stanoiu, I. Stefan, B. Wasilewska, M. Zielińska, M. Ziębliński, 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 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), 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 Laue-Langevin (ILL), ILL, 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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 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, Isotope, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Excited state, 0103 physical sciences, AGATA, Neutron, Nuclear Experiment
Abstract: International audience; An experiment aiming at measuring lifetimes of the second 2+ excited states in neutron-rich C and O isotopes was recently performed at the GANIL laboratory, in France. In these nuclei, recent ab initio calculations provide a detailed description of the nuclear excited states, predicting a strong sensitivity of the electromagnetic transition probabilities to the details of the nucleon–nucleon interactions, especially in connection with the role played by the three-body (NNN) forces. Thus, the measurement of 2 + states lifetimes in this region will be a stringent test of the importance of including the NNN forces in describing the electromagnetic properties of selected nuclear states. This contribution reports on the status of the experimental analysis for the case of lifetimes in 20O.
Published: 2018

40. Statistical study of the prompt-fission γ -ray spectrum for U238(n, f ) in the fast-neutron region

Author: A. Maj, A. Chatillon, L. Morris, L. Qi, P. J. Napiorkowski, S. Courtin, B. Laurent, G. Fruet, M. Lebois, I. Matea, V. Nanal, Stephan Oberstedt, Paola Marini, L. Le Meur, Georgi Georgiev, M. Stanoiu, D. G. Jenkins, Olivier Serot, J. N. Wilson, B. Wasilewska, C. Schmitt, and Andreas Oberstedt
Subjects: Physics, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, 01 natural sciences, Spectral line, Neutron temperature, Time windows, 0103 physical sciences, Neutron, Emission spectrum, Atomic physics, Multiplicity (chemistry), Nuclear Experiment, 010306 general physics
Abstract: Prompt-fission $\ensuremath{\gamma}$-ray spectra (PFGS) have been measured for the $^{238}\mathrm{U}(n,f$) reaction using fast neutrons produced by the LICORNE directional neutron source. Fission events were detected with an ionization chamber containing actinide samples placed in the neutron beam, and the coincident prompt-fission $\ensuremath{\gamma}$ rays were measured using a number of ${\mathrm{LaBr}}_{3}$ scintillation detectors and a cluster of nine phoswich detectors from the PARIS array. Prompt-fission $\ensuremath{\gamma}$ rays (PFGs) were discriminated from prompt-fission neutrons using the time-of-flight technique over distances of around 35 cm. PFG emission spectra were measured at two incident neutron energies of 1.9 and 4.8 MeV for $^{238}\mathrm{U}(n,f$) and also for $^{252}\mathrm{Cf}(sf$) as a reference. Spectral characteristics of PFG emission, such as mean $\ensuremath{\gamma}$ multiplicity and average total $\ensuremath{\gamma}$-ray energy per fission, as well as the average $\ensuremath{\gamma}$-ray energy, were extracted. The sensitivity of these results to the width of the time window and the type of spectral unfolding procedure used to correct for the detector responses was studied. Iteration methods were found to be more stable in low-statistics data sets. The measured values at ${E}_{n}=1.9\phantom{\rule{4.pt}{0ex}}\text{MeV}$ were found to be the mean $\ensuremath{\gamma}$ multiplicity ${\overline{M}}_{\ensuremath{\gamma}}=6.54\ifmmode\pm\else\textpm\fi{}0.19$, total released energy per fission ${E}_{\ensuremath{\gamma},\mathrm{tot}}=5.25\ifmmode\pm\else\textpm\fi{}0.20$ MeV, and the average $\ensuremath{\gamma}$-ray energy ${\ensuremath{\epsilon}}_{\ensuremath{\gamma}}=0.80\ifmmode\pm\else\textpm\fi{}0.04$ MeV. Under similar conditions, the values at ${E}_{n}=4.8\phantom{\rule{4.pt}{0ex}}\text{MeV}$ were measured to be ${\overline{M}}_{\ensuremath{\gamma}}=7.31\ifmmode\pm\else\textpm\fi{}0.46, {E}_{\ensuremath{\gamma},\mathrm{tot}}=6.18\ifmmode\pm\else\textpm\fi{}0.65$ MeV, and ${\ensuremath{\epsilon}}_{\ensuremath{\gamma}}=0.84\ifmmode\pm\else\textpm\fi{}0.11$ MeV.
Published: 2018

41. Experimental Study of the ${^{30}}{\text {P}({\text {p}}}{,}{\gamma })^{31}\text {S}$ Reaction in Classical Novae

Author: A. Georgiadou, A. Gottardo, Alison Laird, N. Oulebsir, Á. M. Sánchez Benítez, F. Flavigny, J. Kiener, A. Coc, F. de Oliveira, J. Riley, D. Beaumel, M. MacCormick, L. Olivier, J. Guillot, L. Grassi, I. Matea, N. Hubbard, Giuseppe D’Agata, C. Delafosse, K. Béroff, Valdir Guimaraes, L. Perrot, S. P. Fox, P. Adsley, N. de Séréville, C. Portail, F. Hammache, A. Meyer, Anuj Parikh, Alessandro Luiz Lara, V. Tatischeff, M. Assié, T. Id Barkach, Marlete Assunção, I. Stefan, B. Bastin, 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), 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 des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), 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 Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Reaction rate, Particle physics, 010308 nuclear & particles physics, 0103 physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, 7. Clean energy
Abstract: International audience; The$^{30}$ P(p, $\gamma $ )$^{31}$ S reaction is one of the few remaining reactions whose rate uncertainty has a strong impact on classical novae model predictions. To reduce the nuclear uncertainties associated to this reaction, we measured the$^{31}$ P($^{3}$ He,t)$^{31}$ S reaction at the ALTO facility. Simultaneous detection of the triton and proton decays from the populated resonances will provide the proton branching ratios. The astrophysical context of this work, the current situation of the$^{30}$ P(p, $\gamma $ )$^{31}$ S reaction rate, the experimental set-up and the analysis of the single and coincidence events will be presented.
Published: 2018

42. Gamma rays as probe of fission and quasi-fission dynamics in the reaction 32S + 197Au near the Coulomb barrier

Author: A. Bracco, E. M. Kozulin, B. de Canditiis, Wladyslaw Henryk Trzaska, I. M. Itkis, C. Petrone, Emanuele Vardaci, V. V. Kirakosyan, P. K. Rath, I. M. Harca, I. Matea, G. Sposito, S. Calinescu, O. Stezowski, C. Schmitt, A. Pulcini, D. Quero, James R. Wilson, N. I. Kozulina, G. La Rana, E. Saveleva, G. N. Knyazheva, K. V. Novikov, S. Brambilla, F. Camera, I. V. Kolesov, M. Ciemala, M. Ashaduzzaman, O. Dorvaux, C. Borcea, A. Maj, Giuseppe Mandaglio, Antonio Trifirò, Marina Trimarchi, Pulcini, A., Vardaci, E., Kozulin, E., Ashaduzzaman, M., Borcea, C., Bracco, A., Brambilla, S., Calinescu, S., Camera, F., Ciemala, M., De Canditiis, Bartolomeo, Dorvaux, O., Harca, I. M., Itkis, I., Kirakosyan, V. V., Knyazheva, G., Kozulina, N., Kolesov, I. V., La Rana, G., Maj, A., Matea, I., Novikov, K., Petrone, C., Quero, D., Rath, P., Saveleva, E., Schmitt, C., Sposito, G., Stezowski, O., Trzaska, W. H., Wilson, J., 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), 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), 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 Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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 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), 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), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Mandaglio, Giuseppe, Trifirò, Antonio, and Trimarchi, Marina
Subjects: Physics, History, Angular momentum, Spectrometer, 010308 nuclear & particles physics, Fission, Detector, gamma radiation, Gamma ray, Coulomb barrier, gammasäteily, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Coincidence, Computer Science Applications, Education, Nuclear physics, nuclear fission, fissio, nuclear physics, 0103 physical sciences, Multiplicity (chemistry), 010306 general physics, ydinfysiikka, Nuclear Experiment
Abstract: International audience; Compound nucleus fission and quasi-fission are both binary decay channels whose common properties make the experimental separation between them difficult. A way to achieve this separation could be to probe the angular momentum of the binary fragments. This can be done detecting gamma rays in coincidence with the two fragments. As a case study, the reaction 32S + 197Au near the Coulomb barrier has been performed at the Tandem ALTO facility at IPN ORSAY. ORGAM and PARIS, two different gamma detectors arrays, are coupled with the CORSET detector, a two-arm time-of-flight spectrometer. TOF-TOF data were analyzed to reconstruct the mass-energy distribution of the primary fragments coupled with gamma multiplicity and spectroscopic analysis. Preliminary results of will be shown.
Published: 2018

43. Prompt fission gamma-ray emission spectral data for 239 Pu(n,f) using fast directional neutrons from the LICORNE neutron source

Author: B. Laurent, Ali Al-Adili, I. Matea, S. J. Rose, L. Qi, B. Wasilewska, Georgi Georgiev, M. Lebois, Joshua N. Wilson, Fabio Zeiser, Stephan Oberstedt, C. Schmitt, Andreas Oberstedt, A. Chatillon, Angélique Gatera, D. Choudhury, Alf Göök, A. Maj, 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), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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), 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 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)
Subjects: Physics, Nuclear reaction, 010308 nuclear & particles physics, Fission, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Neutron temperature, Nuclear physics, 0103 physical sciences, Neutron source, Neutron, 010306 general physics, Nuclear Experiment, Plutonium-239, Spontaneous fission
Abstract: Prompt fission gamma-ray spectra (PFGS) have been measured for the 239Pu(n,f) reaction using fast neutrons at Ēn=1.81 MeV produced by the LICORNE directional neutron source. The setup makes use of LaBr3 scintillation detectors and PARIS phoswich detectors to measure the emitted prompt fission gamma rays (PFG). The mean multiplicity, average total energy release per fission and average energy of photons are extracted from the unfolded PFGS. These new measurements provide complementary information to other recent work on thermal neutron induced fission of 239Pu and spontaneous fission of 252Cf.
Published: 2018
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44. Charged-particle decays of highly excited states in $^{19}$F

Author: I. Stefan, I. Sivacek, Marin Chabot, Jérôme Guillot, A. Gottardo, M. Assié, C. Delafosse, A. Georgiadou, J. Riley, Vincent Tatischeff, L. Perrot, Alison Laird, D. Beaumel, I. Matea, F. Flavigny, Valdir Guimaraes, P. Adsley, Jürgen Kiener, S. P. Fox, R. Garg, M. Degerlier, A. Lefebvre-Schuhl, N. de Sereville, L. Olivier, S. Gillespie, Fairouz Hammache, 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), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, 010308 nuclear & particles physics, Order (ring theory), FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Charged particle, Supernova, Excited state, 0103 physical sciences, Production (computer science), Neutron, Atomic physics, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010303 astronomy & astrophysics
Abstract: Neutron-capture reactions on $^{18}$F in the helium-burning shell play an important role in the production of $^{15}$N during core-collapse supernovae. The competition between the $^{18}$F($n,p/\alpha$)$^{18}$O/$^{15}$N reactions controls the amount of $^{15}$N produced. The strengths of these reactions depend on the decay branching ratios of states in $^{19}$F above the neutron threshold. We report on an experiment investigating the decay branching ratios of these states in order to better constrain the strengths of the reactions., Comment: Submitted as part of the Proceedings of NIC 2018
Published: 2018
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45. Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

Author: A. Maj, C. Portail, F. Rotaru, B. Fornal, M. A. Naumenko, L. Olivier, F. de Oliveira Santos, S. Franchoo, A. Chbihi, P. Bednarczyk, A. V. Karpov, C. Petrone, Bertrand Jacquot, Oleg B. Tarasov, Ł. W. Iskra, Yu. E. Penionzhkevich, F. Azaiez, T. Lauritsen, D. Verney, M. Stanoiu, B. Szpak, F. C. L. Crespi, M. Maccormick, O. Sorlin, O. Kamalou, H. Savajols, I. Stefan, R. V. F. Janssens, I. Matea, N. Cieplicka-Oryńczak, M. Ciemala, Dieter Ackermann, Y. Blumenfeld, S. Leoni, Paola Marini, S. Calinescu, F. Hammache, M. Lewitowicz, S. M. Lukyanov, J. C. Thomas, 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), 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), 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), 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), 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 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)
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Scattering, Projectile, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, lcsh:QC1-999, Momentum, Nuclear physics, Cross section (physics), Deep-inelastic collisions, 0103 physical sciences, Neutron, Nuclear reactions, 010306 general physics, Nuclear Experiment, Beam (structure), lcsh:Physics, Exotic nuclei
Abstract: Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example. Keywords: Nuclear reactions, Deep-inelastic collisions, Exotic nuclei
Published: 2018
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46. Studies of fission fragment yields via high-resolution gamma-ray spectroscopy

Author: K. Hauschild, Stefano Panebianco, A. Gottardo, A. Porta, Gry Merete Tveten, P Amador-Celdran, B. Siebeck, R. Shearman, A. Goasduff, D. Verney, E. Sahin, P. H. Regan, D. T. Doherty, L. Mathieu, Hans-Jurgen E. Hess, A. Lopez-Martens, V. W. Ingeberg, I. Matea, Georgi Georgiev, P. Reiter, G. Lorusso, Olivier Serot, Paola Marini, R Eloirdi, N. Warr, T. Materna, Raymond J. Carroll, Sunniva Siem, Zs. Podolyák, Stephan Oberstedt, Fabio Zeiser, H. De Witte, S. J. Rose, L. Qi, J. N. Wilson, M. Lebois, R. Lutter, J. Ljungvall, K. Rezynkina, D. L. Bleuel, K. Hadynska-Klek, J.A. Briz, M. Zielińska, M. Seidlitz, W. N. Catford, T. Konstantinopoulos, R. Lozeva, A. G. Smith, Andreas Oberstedt, Hambsch, FJ, Carjan, N, Rusko, I, 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), 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 Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), CEA Cadarache, 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), 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), 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 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, Fission products, Science & Technology, Isotopes of uranium, 010308 nuclear & particles physics, Fission, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Physics, Multidisciplinary, Fission product yield, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Neutron temperature, Nuclear physics, Uranium-238, 0103 physical sciences, Physical Sciences, Neutron source, Neutron, 010306 general physics, Nuclear Experiment
Abstract: © The Authors, published by EDP Sciences, 2018. Precise spectroscopic information on the fast neutron induced fission of the 238U(n,f) reaction was recently gained using a new technique which involved coupling of the Miniball high resolution y-ray spectrometer and the LICORNE directional neutron source. The experiment allowed measurement of the isotopic fission yields for around 40 even-even nuclei at an incident neutron energy of around 2 MeV where yield data are very sparse. In addition spectroscopic information on very neutron-rich fission products was obtained. Results were compared to models, both the JEFF-3.1.1 data base and the GEF code, and large discrepancies for the S1 fission mode in the Sn/Mo isotope pair were discovered. This suggests that current models are overestimating the role played by spherical shell effects in fast neutron induced fission. In late 2017 and 2018 the nu-ball hybrid spectrometer will be constructed at the IPN Orsay to perform further experimental investigations with directional neutrons coupled to a powerful hybrid Ge/LaBr3 detector array. This will open up new possibilities for measurements of fission yields for fast-neutron-induced fission using the spectroscopic technique and will be complimentary to other methods being developed. ispartof: SCIENTIFIC WORKSHOP ON NUCLEAR FISSION DYNAMICS AND THE EMISSION OF PROMPT NEUTRONS AND GAMMA RAYS (THEORY-4) vol:169 ispartof: 4th Scientific Workshop on Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays (Theory) location:BULGARIA, Varna date:20 Jun - 22 Jun 2017 status: published
Published: 2018

47. High-precision efficiency calibration of a high-purity co-axial germanium detector

Author: T. Kurtukian Nieto, J. Giovinazzo, J. Souin, H. Guérin, B. Blank, J. C. Thomas, I. Matea, G. Canchel, G. F. Grinyer, M. Gerbaux, L. Audirac, S. Grévy, H. Bouzomita, P. Ascher, P. Delahaye, Noyaux exotiques (NEX), 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)-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), GANILEXP, 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)-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: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Monte Carlo method, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Crystal, Optics, Calibration, Gamma spectroscopy, Gamma-ray spectroscopy, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation, Physics, Monte-Carlosimulations, business.industry, Detector, Germanium detector, Instrumentation and Detectors (physics.ins-det), Semiconductor detector, Super-allowed beta transitions, High Energy Physics::Experiment, Coaxial, business, Energy (signal processing)
Abstract: Expérience GANIL; International audience; A high-purity co-axial germanium detector has been calibrated in efficiency to a precision of about 0.15% over a wide energy range. High-precision scans of the detector crystal and gamma-ray source measurements have been compared to Monte-Carlo simulations to adjust the dimensions of a detector model. For this purpose, standard calibration sources and short-lived on-line sources have been used. The resulting efficiency calibration reaches the precision needed e.g. for branching ratio measurements of super-allowed beta decays for tests of the weak-interaction standard model.
Published: 2015

48. Study of key resonances in the $^{30}$P(p,γ)$^{31}$S reaction in classical novae

Author: F. Flavigny, L. Olivier, A. Alellara, B. Bastin, L. Perrot, J. Riley, L. Grassi, F. de Oliveira, T. Id Barkach, J. Guillot, Alison Laird, J. Kiener, Á. M. Sánchez Benítez, D. Beaumel, V. Tatischeff, Marlete Assunção, Anuj Parikh, S. P. Fox, A. Meyer, P. Adsley, Giuseppe D’Agata, C. Portail, A. Gottardo, F. Hammache, I. Matea, M. Assié, N. Oulebsir, A. Georgiadou, C. Delafosse, M. MacCormick, N. Hubbard, Valdir Guimaraes, A. Coc, N. de Séréville, I. Stefan, K. Béroff, 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), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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 des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), 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), 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 Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Proton, 010308 nuclear & particles physics, QC1-999, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Coincidence, Nuclear physics, Reaction rate, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Excited state, 0103 physical sciences, 010303 astronomy & astrophysics
Abstract: Among reactions with strong impact on classical novae model predictions, 30P(p,γ)31S is one of the few remained that are worthy to be measured accurately, because of their rate uncertainty, as like as 18F(p,α)15O and 25Al(pγ)26Si. To reduce the nuclear uncertainties associated to this reaction, we performed an experiment at ALTO facility of Orsay using the 31P(3He,t)31S reaction to populate 31S excited states of astrophysical interest and detect in coincidence the protons coming from the decay of the populated states in order to extract the proton branching ratios. After a presentation of the astrophysical context of this work, the current situation of the 30P(p,γ)31S reaction rate will be discussed. Then the experiment set-up of this work and the analysis of the single events will be presented.
Published: 2017

49. Shell Evolution towards Ni78 : Low-Lying States in Cu77

Author: Hirofumi Watanabe, Atsuko Odahara, Giuseppe Lorusso, D. Mengoni, Megumi Niikura, K. Matsui, Tomio Kubo, H. Schaffner, Zs. Vajta, I. Stefan, F. Browne, Takaharu Otsuka, Toshiyuki Sumikama, Z. H. Li, I. Kojouharov, M.-C. Delattre, D. Suzuki, Shin-Ichiro Nishimura, Hiroki Nishibata, G. de Angelis, K. Yoshinaga, T. Isobe, Dóra Sohler, Ryo Taniuchi, G. Gey, P. Morfouace, I. Matea, Yusuke Tsunoda, S. Franchoo, K. Hadyńska-Klȩk, H. S. Jung, Jan Taprogge, Zhengyu Xu, Hiroyoshi Sakurai, D. R. Napoli, V. Werner, Andreas Görgen, M. Yalcinkaya, Ayumi Yagi, E. Sahin, P. R. John, F. L. Bello Garrote, P. Doornenbal, P. A. Söderström, F. Naqvi, H. Baba, Jinguang Wu, and N. Kurz
Subjects: Physics, 010308 nuclear & particles physics, Fission, Center (category theory), Shell (structure), General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Ion, Excited state, 0103 physical sciences, Cluster (physics), Level structure, Atomic physics, 010306 general physics, Spectroscopy
Abstract: The level structure of the neutron-rich ^{77}Cu nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the β decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near ^{78}Ni and suggests a single-particle nature for both the 5/2_{1}^{-} and 3/2_{1}^{-} states in ^{77}Cu, leading to doubly magic ^{78}Ni.
Published: 2017

50. Anomalies in the Charge Yields of Fission Fragments from the U(n,f)238 Reaction

Author: M. Zielińska, Stefano Panebianco, H. De Witte, S. J. Rose, V. W. Ingeberg, P. Reiter, K. Hadynska-Klek, M. Seidlitz, K. Rezynkina, W. N. Catford, Andreas Oberstedt, N. Warr, Paola Marini, D. L. Bleuel, P. H. Regan, D. Verney, A. G. Smith, M. Lebois, Stephan Oberstedt, Olivier Serot, J. N. Wilson, T. Konstantinopoulos, Amanda Porta, Fabio Zeiser, R. Lozeva, R. Shearman, R. Lutter, B. Siebeck, A. Goasduff, G. Lorusso, Georgi Georgiev, J. Ljungvall, Sunniva Siem, L. Mathieu, E. Sahin, D. T. Doherty, L. Qi, Hans-Jurgen E. Hess, R Eloirdi, I. Matea, A. Lopez-Martens, T. Materna, K. Hauschild, José Antonio Briz, Gry Merete Tveten, P Amador-Celdran, A. Gottardo, Raymond J. Carroll, and Zs. Podolyák
Subjects: Physics, Cold fission, Cluster decay, 010308 nuclear & particles physics, Neutron emission, Fission, Xenon-135, Isotopes of samarium, Nuclear Theory, General Physics and Astronomy, Fission product yield, 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Neutron, Nuclear Experiment, 010306 general physics
Abstract: Fast-neutron-induced fission of 238U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ−γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.
Published: 2017

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