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38 results on '"Ch, Theisen"'

1. Pairing-quadrupole interplay in the neutron-deficient tin nuclei: First lifetime measurements of low-lying states in 106,108Sn

Author

M. Siciliano, J.J. Valiente-Dobón, A. Goasduff, F. Nowacki, A.P. Zuker, D. Bazzacco, A. Lopez-Martens, E. Clément, G. Benzoni, T. Braunroth, F.C.L. Crespi, N. Cieplicka-Oryńczak, M. Doncel, S. Ertürk, G. de France, C. Fransen, A. Gadea, G. Georgiev, A. Goldkuhle, U. Jakobsson, G. Jaworski, P.R. John, I. Kuti, A. Lemasson, T. Marchi, D. Mengoni, C. Michelagnoli, T. Mijatović, C. Müller-Gatermann, D.R. Napoli, J. Nyberg, M. Palacz, R.M. Pérez-Vidal, B. Sayği, D. Sohler, S. Szilner, D. Testov, M. Zielińska, D. Barrientos, B. Birkenbach, H.C. Boston, A.J. Boston, B. Cederwall, J. Collado, D.M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Dudouet, J. Eberth, F.J. Egea-Canet, V. González, L.J. Harkness-Brennan, H. Hess, D.S. Judson, A. Jungclaus, W. Korten, M. Labiche, A. Lefevre, S. Leoni, H. Li, A. Maj, R. Menegazzo, B. Million, A. Pullia, F. Recchia, P. Reiter, M.D. Salsac, E. Sanchis, O. Stezowski, and Ch. Theisen

Subjects
Lifetime, Nuclear structure, Multi-nucleon transfer, Light Sn, Tracking array, Physics, QC1-999
Abstract

The lifetimes of the low-lying excited states 2+ and 4+ have been directly measured in the neutron-deficient 106,108Sn isotopes. The nuclei were populated via a deep-inelastic reaction and the lifetime measurement was performed employing a differential plunger device. The emitted γ rays were detected by the AGATA array, while the reaction products were uniquely identified by the VAMOS++ magnetic spectrometer. Large-Scale Shell-Model calculations with realistic forces indicate that, independently of the pairing content of the interaction, the quadrupole force is dominant in the B(E2;21+→0g.s.+) values and it describes well the experimental pattern for 104−114Sn; the B(E2;41+→21+) values, measured here for the first time, depend critically on a delicate pairing-quadrupole balance, disclosed by the very precise results in 108Sn.

Published
2020
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2. Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

Author

J. Konki, J. Khuyagbaatar, J. Uusitalo, P.T. Greenlees, K. Auranen, H. Badran, M. Block, R. Briselet, D.M. Cox, M. Dasgupta, A. Di Nitto, Ch.E. Düllmann, T. Grahn, K. Hauschild, A. Herzán, R.-D. Herzberg, F.P. Heßberger, D.J. Hinde, R. Julin, S. Juutinen, E. Jäger, B. Kindler, J. Krier, M. Leino, B. Lommel, A. Lopez-Martens, D.H. Luong, M. Mallaburn, K. Nishio, J. Pakarinen, P. Papadakis, J. Partanen, P. Peura, P. Rahkila, K. Rezynkina, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, S. Stolze, B. Sulignano, Ch. Theisen, A. Ward, A. Yakushev, and V. Yakusheva

Subjects
Isotopes with mass 236–240, 240Es, 236Bk, α decay, Electron-capture delayed fission, Fusion–evaporation reactions, Physics, QC1-999
Abstract

The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion–evaporation reaction 209Bi(34S,3n)240Es. Half-lives of 6(2)s and 22−6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα=8.19(3)MeV and 8.09(3)MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16(6) and 0.04(2) were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

Published
2017
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3. Conceptual design of the AGATA 2π array at LNL

Author

J.J. Valiente-Dobón, R. Menegazzo, A. Goasduff, D. Agguiaro, P. Aguilera, F. Angelini, M. Balogh, D. Bazzacco, J. Benito, G. Benzoni, N. Bez, M. Bolognesi, S. Bottoni, D. Brugnara, S. Carollo, P. Cocconi, A. Cogo, J. Collado, F.C.L. Crespi, A. Ertoprak, R. Escudeiro, F. Galtarossa, E.R. Gamba, A. Gambalonga, B. Góngora Servín, A. Gottardo, A. Gozzelino, M. Gulmini, Z. Huang, T. Marchi, D. Mengoni, P. Modanese, D.R. Napoli, J. Pellumaj, R.M. Pérez-Vidal, S. Pigliapoco, E. Pilotto, L. Ramina, M. Rampazzo, W. Raniero, M. Rebeschini, K. Rezynkina, D. Rosso, M. Scarcioffolo, D. Scarpa, M. Sedlák, R. Smith, N. Toniolo, F. Veronese, V. Volpe, L. Zago, I. Zanon, G. Zhang, R. Abels, M.L. Allegrini, C. Aufranc, G. Baulieu, C. Belkhiria, M. Benettoni, D. Benini, M. Bentley, M. Biasotto, M. Blaizot, J. Blasco Miquel, C. Boiano, A. Boston, H. Boston, A. Boujrad, P. Bourgault, A. Bracco, S. Brambilla, I. Burrows, F. Camera, S. Capra, A. Capsoni, R. Cash, J.V. Civera, E. Clément, S. Coelli, M. Cordwell, L. Corradi, S. Coudert, G. De Angelis, L. De Ruvo, G. Debras, M. Del Fabbro, J. Diklić, N. Dosme, G. Duchene, B. Duclos, J. Dudouet, J. Eberth, S. Elloumi, C. Everett, S. Fantinel, M. Fillinger, E. Fioretto, C. Fransen, A. Gadea, L. Gibelin, V. González, J. Goupil, C. Görgen, A. Grant, K. Green, J. Ha, T. Hartnett, K. Henseler, H. Hess, R. Hirsch, C. Houarner, J. Jacob, T. Joannem, D.S. Judson, N. Karkour, M. Karolak, M. Kebbiri, J. Kieffer, M. Labiche, X. Lafay, P. Le Jeannic, A. Lefevre, E. Legay, F. Legruel, S. Lenzi, S. Leoni, D. Linget, M. Liptrot, A. López-Martens, A. Lotodé, L. Manara, L. Ménager, T. Mijatović, B. Million, A. Minarello, G. Montagnoli, P. Morrall, I. Mullacrane, J. Nyberg, G. Philippon, M. Polettini, F. Popieul, A. Pullia, F. Recchia, P. Reiter, G. Richardt, M. Rocchini, A. Roger, F. Saillant, E. Sanchis, Md.S.R. Laskar, G. Secci, M.-H. Sigward, J. Simpson, N. Solenne, F. Spee, A.M. Stefanini, O. Stézowski, S. Szilner, N. Templeton, Ch. Theisen, S. Thiel, F. Tomasi, S. Tzvetkov, D. Vigano, E. Viscione, O. Wieland, K. Wimmer, G. Wittwer, M. Zielińska, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), 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), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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 Pluridisciplinaire Hubert Curien (IPHC), 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
AGATA spectrometer, DANTE detector, EUCLIDES detector, LNL facility, Plunger device, PRISMA spectrometer, Pulse shape analysis, TRACE detector, γ-ray tracking, Nuclear and High Energy Physics, Settore FIS/04 - Fisica Nucleare e Subnucleare, ray tracking, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation
Abstract

International audience; The Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1π, and progressively the number of ATCs will increase up to a 2π angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem–PIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy γ-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL.

Published
2023
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4. Evidence of Partial Seniority Conservation in the πg_{9/2} Shell for the N=50 Isotones

Author

R M, Pérez-Vidal, A, Gadea, C, Domingo-Pardo, A, Gargano, J J, Valiente-Dobón, E, Clément, A, Lemasson, L, Coraggio, M, Siciliano, S, Szilner, M, Bast, T, Braunroth, J, Collado, A, Corina, A, Dewald, M, Doncel, J, Dudouet, G, de France, C, Fransen, V, González, T, Hüyük, B, Jacquot, P R, John, A, Jungclaus, Y H, Kim, A, Korichi, M, Labiche, S, Lenzi, H, Li, J, Ljungvall, A, López-Martens, D, Mengoni, C, Michelagnoli, C, Müller-Gatermann, D R, Napoli, A, Navin, B, Quintana, D, Ramos, M, Rejmund, E, Sanchis, J, Simpson, O, Stezowski, D, Wilmsen, M, Zielińska, A J, Boston, D, Barrientos, P, Bednarczyk, G, Benzoni, B, Birkenbach, H C, Boston, A, Bracco, B, Cederwall, D M, Cullen, F, Didierjean, J, Eberth, A, Gottardo, J, Goupil, L J, Harkness-Brennan, H, Hess, D S, Judson, A, Kaşkaş, W, Korten, S, Leoni, R, Menegazzo, B, Million, J, Nyberg, Zs, Podolyak, A, Pullia, D, Ralet, F, Recchia, P, Reiter, K, Rezynkina, M D, Salsac, M, Şenyiğit, D, Sohler, Ch, Theisen, D, Verney, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, European Commission, Department of Energy (US), Croatian Science Foundation, and Pérez-Vidal, R.M.

Abstract

7 pags., 3 figs., 1 tab., The reduced transition probabilities for the 4_{1}^{+}→2_{1}^{+} and 2_{1}^{+}→0_{1}^{+} transitions in ^{92}Mo and ^{94}Ru and for the 4_{1}^{+}→2_{1}^{+} and 6_{1}^{+}→4_{1}^{+} transitions in ^{90}Zr have been determined in this experiment making use of a multinucleon transfer reaction. These results have been interpreted on the basis of realistic shell-model calculations in the f_{5/2}, p_{3/2}, p_{1/2}, and g_{9/2} proton valence space. Only the combination of extensive lifetime information and large scale shell-model calculations allowed the extent of the seniority conservation in the N=50 g_{9/2} orbital to be understood. The conclusion is that seniority is largely conserved in the first πg_{9/2} orbital., This work was partially supported by MCIN/AEI/10.13039/501100011033 and Generalitat Valenciana, Spain, under Grants No. FPA2017-84756-C4, No. PID2020–118265GB-C4, and No. PROMETEO 2019/005, by the EU FEDER funds, by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. n654002, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357, by STFC(UK) and by the Croatian Science Foundation under Projects No. 7194 and No. IP-2018-01-1257.

Published
2022

5. Evidence of Partial Seniority Conservation in the πg9/2 Shell for the N=50 Isotones

Author

R. M. Pérez-Vidal, A. Gadea, C. Domingo-Pardo, A. Gargano, J. J. Valiente-Dobón, E. Clément, A. Lemasson, L. Coraggio, M. Siciliano, S. Szilner, M. Bast, T. Braunroth, J. Collado, A. Corina, A. Dewald, M. Doncel, J. Dudouet, G. de France, C. Fransen, V. González, T. Hüyük, B. Jacquot, P. R. John, A. Jungclaus, Y. H. Kim, A. Korichi, M. Labiche, S. Lenzi, H. Li, J. Ljungvall, A. López-Martens, D. Mengoni, C. Michelagnoli, C. Müller-Gatermann, D. R. Napoli, A. Navin, B. Quintana, D. Ramos, M. Rejmund, E. Sanchis, J. Simpson, O. Stezowski, D. Wilmsen, M. Zielińska, A. J. Boston, D. Barrientos, P. Bednarczyk, G. Benzoni, B. Birkenbach, H. C. Boston, A. Bracco, B. Cederwall, D. M. Cullen, F. Didierjean, J. Eberth, A. Gottardo, J. Goupil, L. J. Harkness-Brennan, H. Hess, D. S. Judson, A. Kaşkaş, W. Korten, S. Leoni, R. Menegazzo, B. Million, J. Nyberg, Zs. Podolyak, A. Pullia, D. Ralet, F. Recchia, P. Reiter, K. Rezynkina, M. D. Salsac, M. Şenyiğit, D. Sohler, Ch. Theisen, and D. Verney

Subjects
General Physics and Astronomy
Published
2022
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6. First observation of high-K isomeric states in $$^{249}$$Md and $$^{251}$$Md

Author

F. Defranchi Bisso, P. Jachimowicz, Mikael Sandzelius, Paul Greenlees, Kalle Auranen, P. Peura, Ch. Theisen, R.-D. Herzberg, R. Julin, P. Rahkila, T. Grahn, M. Vandebrouck, J. Skalski, A. Drouart, Jan Sarén, R. Briselet, H. Badran, T. Calverley, J. Rubert, Joonas Konki, P. Nieminen, Matti Leino, B. J. P. Gall, Daniel Cox, A. Ward, C. Scholey, M. Kowal, U. Jakobsson, M. Airiau, F. Déchery, Philippos Papadakis, Panu Ruotsalainen, Jari Partanen, Janne Pakarinen, Z. Favier, Juha Uusitalo, T. Goigoux, B. Sulignano, A. Lopez-Martens, M. Zielińska, K. Hauschild, S. Stolze, E. Rey-Herme, A. K. Mistry, Juha Sorri, S. Juutinen, A. Herzáň, A. Lightfoot, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut 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), 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 de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Nuclear Theory, nucl-th, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], isomeria, Hadron, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 7. Clean energy, 01 natural sciences, Nuclear Theory (nucl-th), 0103 physical sciences, Nuclear fusion, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Spectroscopy, Physics, 010308 nuclear & particles physics, Fermi surface, State (functional analysis), puoliintumisaika, Nuclear Physics - Theory, Excited state, Quasiparticle, Atomic physics, ydinfysiikka, Excitation
Abstract

Decay spectroscopy of the odd-proton nuclei $^{249}$Md and $^{251}$Md has been performed. High-K isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of 2.8(5) ms and an excitation energy $\ge 910$ keV was found in $^{249}$Md. In $^{251}$Md, an isomeric state with a half-life of 1.4(3) s and an excitation energy $\ge 844$ keV was found. Similarly to the neighbouring $^{255}$Lr, these two isomeric states are interpreted as 3 quasi-particle high-K states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen–Cooper–Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods–Saxon potential. The most probable candidates for the configurations of K-isomeric states in Md nuclei are proposed. Decay spectroscopy of the odd-proton nuclei $^{249}$Md and $^{251}$Md has been performed. High-$K$ isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of $2.8(5)$ ms and an excitation energy $\geq 910$ keV was found in $^{249}$Md. In $^{251}$Md, an isomeric state with a half-life of $1.4(3)$ s and an excitation energy $\geq 844$ keV was found. Similarly to the neighbouring $^{255}$Lr, these two isomeric states are interpreted as 3 quasi-particle high-$K$ states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen-Cooper-Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods-Saxon potential. The most probable candidates for the configurations of $K$-isomeric states in Md nuclei are proposed.

Published
2021
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7. Reinterpretation of excited states in Po212 : Shell-model multiplets rather than α -cluster states

Author

B. Million, E. Dupont, Bertrand Jacquot, R. Menegazzo, M. Ciemala, M. Zielińska, R. M. Perez-Vidal, L. J. Harkness-Brennan, D. Mengoni, Vicente González, W. Korten, D. Kocheva, D. Ralet, D. R. Napoli, P. Reiter, J. Eberth, Zs. Podolyák, A. Astier, B. Birkenbach, C. Michelagnoli, G. Tocabens, A. Perea, J. Dudouet, Ch. Lorenz, A. Bracco, A. Maj, M. Jurado, Begoña Quintana, A. Fernández, H. C. Boston, J. Ropert, J. Ljungvall, L. Ménager, Dirk Rudolph, G. Benzoni, H. Naïdja, E. Nácher, A. Korichi, A. Jungclaus, K. Wimmer, J. J. Valiente-Dobón, C. Houarner, A. Gadea, Johan Nyberg, J. Collado, A. Pullia, A. Gargano, Hans-Jurgen E. Hess, A. J. Boston, Emyr Clement, J. Goupil, A. Såmark-Roth, Enrique Sanchis, Diego Barrientos, S. Leoni, G. Frémont, N. Lalović, F. Saillant, D. S. Judson, O. Stezowski, A. Lemasson, C. Spitaels, S. Ansari, G. S. Simpson, D. M. Cullen, A. Illana, N. Redon, Luis Sarmiento, C. M. Petrache, G. Rainovski, Ch. Theisen, H. J. Li, C. Domingo-Pardo, and Pavel Golubev

Subjects
Reinterpretation, Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, SHELL model, Cluster (physics), Atomic physics, 010306 general physics, 01 natural sciences
Published
2021
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8. NEWGAIN White Book - Science Requirements - Work Package Physics

Author

Ackermann, D., Blank, B., Caceres, L., Caamaño, M., France, G., Gall, B., Grévy, S., Grygiel, C., Lamour, E., Ledoux, X., Manea, V., Ch. Peaucelle, Rangama, J., Redon, N., Gheorghe Iulian Stefan, Ch. Stodel, Sulignano, B., Ch. Theisen, 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 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), Universidade de Santiago de Compostela [Spain] (USC ), 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), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Matériaux, Défauts et IRradiations (MADIR), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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 Physique des 2 Infinis de Lyon (IP2I Lyon), 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), Atomes, Molécules et Agrégats (AMA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, GANIL - document link: https://www.ganil-spiral2.eu/scientists/ganil-spiral-2-facilities/accelerators/newgain, 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), 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), 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)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

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

The new injector for SPIRAL2 at GANIL, NEWGAIN is presently in its design phase. The major constraints for its technical concepts are determined by the requirements of its future users, the national French and the international scientific communities. The facility will offer heavy ion beams of unmatched intensity for fundamental and applied research. This document reports on the specific requirements of the scientific communities in terms of beam energy, intensity, time structure and other features which are needed to conduct the envisaged research programs at the experimental installations, which are or will be coupled to the linear accelerator of the SPIRAL2 facility at GANIL. It aims at fostering the information exchange between the scientific community and the technical and engineering team who is designing, planning and constructing NEWGAIN. The document has been elaborated by the members of the Work Package Physics (WPP) of the NEWGAIN project, consisting of the scientific coordinators of the institutions contributing to and participating in NEWGAIN, and representatives of the various scientific collaborations engaged in the exploitation of the SPIRAL2 accelerator facility. The document is organized with active links to sections, subsections, figures, tables and literature references integrated in the text.

Published
2021

9. In-beam γ -ray and electron spectroscopy of Md249,251

Author

Mikael Sandzelius, A. Drouart, J. Rubert, P. Ruotsalainen, F. Dechery, S. Juutinen, B. Bally, R.-D. Herzberg, A. K. Mistry, Tuomas Grahn, Philippos Papadakis, Jan Sarén, Wouter Ryssens, Panu Rahkila, Z. Favier, Kalle Auranen, Pauli Peura, Juha Uusitalo, A. Ward, Janne Pakarinen, K. Hauschild, Paivi Nieminen, C. Scholey, Andrej Herzan, M. Vandebrouck, M. Airiau, Ch. Theisen, Sanna Stolze, T. Goigoux, Matti Leino, B. J. P. Gall, R. Briselet, Paul Greenlees, M. Zielińska, B. Sulignano, A. Lopez-Martens, Ulrika Jakobsson, J. Konki, M. Bender, Daniel Cox, R. Julin, E. Rey-Herme, and Juha Sorri

Subjects
Physics, Angular momentum, 010308 nuclear & particles physics, Nuclear structure, Electron, 01 natural sciences, Electron spectroscopy, Atomic orbital, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Beam (structure)
Abstract

The odd-Z Md251 nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2− configuration, another rotational structure has been identified using γ-γ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2− single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely gK=0.69−0.16+0.19 for the ground-state band. The odd-Z Md249 was studied using γ-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the Δl=Δj=3 [521]3/2− and [633]7/2+ Nilsson orbitals were found in both Md249,251. A surprising similarity of the Md251 ground-state band transition energies with those of the excited band of Lr255 has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands.

Published
2020
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10. 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
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11. Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus Ru88

Author

Eric Clément, B. Birkenbach, M. Zielińska, B. Million, M. Doncel, C. Domingo-Pardo, F. Recchia, J. Ljungvall, R. M. Perez-Vidal, Torbjörn Bäck, P. Reiter, P. Bednarczyk, J. Simpson, D. Mengoni, J. J. Valiente-Dobón, A. Lemasson, W. Korten, W. Zhang, X. Liu, B. M. Nyako, A. J. Boston, J. Goupil, H. Al-Azri, Diego Barrientos, M. D. Salsac, F. C. L. Crespi, A. Jungclaus, A. Gadea, A. Maj, N. Erduran, P. Désesquelles, A. Gottardo, Ch. Theisen, T. Hüyük, János Timár, Alberto Pullia, Vicente González, L. Charles, Zs. Podolyák, R. Menegazzo, C. M. Petrache, D. M. Cullen, S. Erturk, A. Ataç Nyberg, M. Jurado, Herbert Hess, Chong Qi, O. Aktas, Bo Cederwall, István Kuti, D. R. Napoli, Johan Nyberg, Alain Goasduff, D. Ralet, Enrique Sanchis, A. Ertoprak, M. Palacz, F. Saillant, D. Sohler, O. Stezowski, R. Wadsworth, J. Dudouet, G. de Angelis, M. Ciemala, G. Jaworski, J. Eberth, H. C. Boston, G. Benzoni, I. Burrows, and S. Leoni

Subjects
Physics, Isovector, Isoscalar, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Charged particle, Nuclear physics, 13. Climate action, Isospin, Excited state, 0103 physical sciences, Neutron detection, AGATA, Neutron, Nuclear Experiment, 010306 general physics
Abstract

The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N = Z) nuclide 88 44Ru44 has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in 88Ru were populated via the 54Fe(36Ar; 2n )88Ru fusion-evaporation reaction at the Grand Acc�el�erateur National d'Ions Lourds (GANIL) accelerator complex. The observed -ray cascade is assigned to 88Ru using clean prompt - -2-neutron coincidences in anti-coincidence with the detection of charged particles, con�rming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N > Z nuclides. The direct observation of such a \delayed" rotational alignment in a deformed N = Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.

Published
2020
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12. Stability of the heaviest elements: K isomer in No250

Author

M. Zielińska, B. Sulignano, Ulrika Jakobsson, A. Drouart, J. Khuyagbaatar, J. Kallunkathariyil, P. Papadakis, R. Briselet, S. Stolze, T. Goigoux, A. Ward, M. Siciliano, Jari Partanen, Janne Pakarinen, Joonas Konki, J. Sorri, Pauli Peura, A. Herzan, C. Scholey, Panu Ruotsalainen, Ch. Theisen, T. Grahn, M. Vandebrouck, S. Juutinen, R. Julin, A. I. Svirikhin, A. Lightfoot, F. P. Heßberger, K. Hauschild, Matti Leino, K. Rezynkina, Paul Greenlees, H. Badran, C. Wraith, F. Bisso, Mikael Sandzelius, P. Brionnet, Kalle Auranen, Z. Favier, P. Rahkila, Juha Uusitalo, and Jan Sarén

Subjects
Physics, 010308 nuclear & particles physics, Fission, Nuclear structure, State (functional analysis), 7. Clean energy, 01 natural sciences, Stability (probability), Island of stability, 0103 physical sciences, Atomic physics, 010306 general physics, Ground state, Spectroscopy, Spontaneous fission
Abstract

Decay spectroscopy of No250 has been performed using digital electronics and pulse-shape analysis of the fast nuclear decays for the first time. Previous studies of No250 reported two distinct fission decay lifetimes, related to the direct fission of the ground state and to the decay of an isomeric state but without the possibility to determine if the isomeric state decayed directly via fission or via internal electromagnetic transitions to the ground state. The data obtained in the current experiment allowed the puzzle to finally be resolved, attributing the shorter half-life of t1/2=3.8±0.3μs to the ground state and the longer half-life t1/2=34.9−3.2+3.9μs to the decay of an isomeric state. No250 becomes, thus, one of a very few examples of very heavy nuclei with an isomeric state living considerably longer than its ground state. This phenomenon has important consequences for the nuclear-structure models aiming to determine the borders of the island of stability of superheavy elements.

Published
2020
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13. Physics opportunities with the Advanced Gamma Tracking Array: AGATA

Author

W. Korten, A. Bracco, A. Atac, G. Benzoni, S. Leoni, P. Reiter, A. Goasduff, Eric Clément, K. A. Gladnishki, F. Recchia, A. Jungclaus, Bo Cederwall, G. Duchêne, D. G. Jenkins, A. Nannini, P. Bednarczyk, M. Zielińska, Dirk Rudolph, Riccardo Raabe, B. Million, A. Tumino, P. J. Nolan, D. R. Napoli, B. Fernández-Domínguez, F. Didierjean, Johan Nyberg, Herbert Hess, A. Gadea, D. Tonev, M. Ciemala, G. Rainovski, D. T. Doherty, Joakim Cederkäll, A. Obertelli, J. Gerl, J. J. Valiente-Dobón, B. Fornal, Begoña Quintana, J. Ljungvall, Ch. Theisen, Janne Pakarinen, G. de Angelis, P. R. John, M. Kmiecik, O. Wieland, Zs. Dombrádi, J. Simpson, A. J. Boston, M. Górska, Zs. Podolyák, D. Curien, J. Dudek, Norbert Pietralla, F. C. L. Crespi, A. Maj, K. Wimmer, Paul Greenlees, D. Beaumel, M. Labiche, A. Lopez-Martens, A. Korichi, M. A. Bentley, D. Mengoni, Liam Gaffney, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut 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 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), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), AGATA, 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), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Ministerio de Ciencia, Innovación y Universidades (España), 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
Radioactive ion beams, Nuclear and High Energy Physics, NEUTRON-RICH, Position resolution, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Accelerator Physics and Instrumentation, Tracking (particle physics), 7. Clean energy, 01 natural sciences, Physics, Particles & Fields, Subatomär fysik, Optics, Subatomic Physics, 0103 physical sciences, Gamma spectroscopy, SPECTROMETER, ddc:530, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], SUPERHEAVY ELEMENTS, 010306 general physics, ROTATIONAL BAND, DETECTOR, Physics, Science & Technology, Spectrometer, 010308 nuclear & particles physics, business.industry, European research, Detector, Acceleratorfysik och instrumentering, FISSION-BARRIERS, PERFORMANCE, Physics, Nuclear, SPIN, Physical Sciences, SHELL-MODEL, AGATA, business, DECAY
Abstract

AGATA Collaboration, New physics opportunities are opening up by the Advanced Gamma Tracking Array, AGATA, as it evolves to the full 4π instrument. AGATA is a high-resolution γ-ray spectrometer, solely built from highly segmented high-purity Ge detectors, capable of measuring γ rays from a few tens of keV to beyond 10 MeV, with unprecedented efficiency, excellent position resolution for individual γ-ray interactions, and very high count-rate capability. As a travelling detector AGATA will be employed at all major current and near-future European research facilities delivering stable and radioactive ion beams., The AGATA project has been supported by the European Structural Funds FSE FEDER, the Academy of Finland FIRI program, Finland, the Direction de Recherches Fondamentales of CEA, France, the Institut National de Physique Nucléaire et de Physique des Particules (IN2P3) of CNRS, France, the Bundesministerium für Bildung und Forschung (BMBF), Germany, the Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Hungary, the IstitutoNazionale di Fisica Nucleare (INFN), Italy, theNational Science Center (NCN), Poland, the Knut and AliceWallenberg foundation (Sweden), the Swedish Research Council, the Conselleria d’Educació, Investigació, Cultura i Esport, Generalitat Valenciana and Ministerio de Ciencia, Innovación y Universidades, Spain, the Türkiye Bilimsel ve Teknolojik Ara¸stirma Kurumu (TÜBITAK), Turkey, and the United Kingdom Research and Innovation – Science and Technology Facilities Council (UKRI-STFC).

Published
2020
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14. Lifetime measurements in Ti52,54 to study shell evolution toward N=32

Author

A. Lemasson, W. Korten, Thomas Braunroth, Herbert Hess, C. Müller-Gatermann, C. Domingo-Pardo, J. Simpson, I. Burrows, S. Leoni, P. Reiter, C. Fransen, A. Vogt, Bertrand Jacquot, C. Houarner, D. M. Cullen, C. Henrich, A. Lefevre, A. Atac, M. Zielińska, M. Ciemala, N. Ménard, F. Legruel, A. J. Boston, J. Eberth, A. Goldkuhle, M. Labiche, H. C. Boston, Alberto Pullia, G. Voltolini, K. O. Zell, A. Korichi, J. Ljungvall, R. M. Pérez-Vidal, L. Ménager, J.-L. Foucher, C. Barthe-Dejean, C. Michelagnoli, Diego Barrientos, A. Dewald, J. Ropert, B. Birkenbach, Y. H. Kim, O. Stezowski, P. Bourgault, A. Blazhev, G. Frémont, J. Goupil, D. Ralet, Bo Cederwall, G. Benzoni, Ch. Theisen, N. Warr, A. Gadea, H. J. Li, A. Maj, Johan Nyberg, M. D. Salsac, S. M. Lenzi, M. Jean, J. J. Valiente Dobon, C. Maugeais, L. Legeard, P. Gangnant, A. Navin, M. Ozille, B. Million, M. Tripon, B. S. Nara Singh, Enrique Sanchis, D. R. Napoli, Emyr Clement, J. Dudouet, F. Saillant, Vicente González, F. Recchia, Ch. Schmitt, H. Munoz, Zs. Podolyák, B. Raine, M. Beckers, Roberto Menegazzo, D. Mengoni, J. Cacitti, J. Litzinger, J. Jolie, D. S. Judson, C. Spitaels, and M. Toulemonde

Subjects
Plunger, Physics, 010308 nuclear & particles physics, Excited state, Nuclear Theory, 0103 physical sciences, Shell (structure), Atomic physics, Nuclear Experiment, 010306 general physics, 7. Clean energy, 01 natural sciences
Abstract

Lifetimes of the excited states in the neutron-rich Ti-52,Ti-54 nuclei, produced in a multinucleon-transfer reaction, were measured by employing the Cologne plunger device and the recoil-distance D ...

Published
2019
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15. Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich Sb51122–131 isotopes

Author

L. J. Harkness-Brennan, H. L. Crawford, Alberto Pullia, M. Rejmund, A. Jungclaus, B. Birkenbach, G. Benzoni, A. Lefevre, J. J. Valiente-Dobón, J. Goupil, Bo Cederwall, M. D. Salsac, P. Bednarczyk, Ch. Theisen, H. J. Li, A. J. Boston, R. Banik, Diego Barrientos, Vicente González, J. Eberth, O. Stezowski, Sumita Bhattacharyya, V. Morel, H. C. Boston, D. Ralet, D. Mengoni, A. Lemasson, D. M. Cullen, I. Stefan, Bertrand Jacquot, R. Menegazzo, D. R. Napoli, Herbert Hess, J. Collado, P. Fallon, J. Dudouet, C. Michelagnoli, R. Palit, G. Frémont, Y. H. Kim, S. Biswas, P. Désesquelles, R. M. Pérez-Vidal, M. Zielińska, Soumik Bhattacharya, A. Navin, Enrique Sanchis, F. Saillant, W. Korten, B. Million, J. Ropert, Begoña Quintana, J. Ljungvall, L. Ménager, Eric Clément, F. Recchia, A. Maj, M. Labiche, P. Reiter, and C. Domingo-Pardo

Subjects
Physics, Angular momentum, Valence (chemistry), Isotope, 010308 nuclear & particles physics, Fission, Nuclear Theory, Nuclear structure, 7. Clean energy, 01 natural sciences, Neutron number, 0103 physical sciences, AGATA, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

Background: Levels fulfilling the seniority scheme and relevant isomers are commonly observed features in semimagic nuclei; for example, in Sn isotopes (Z=50). Seniority isomers in Sn, with dominantly pure neutron configurations, directly probe the underlying neutron-neutron (νν) interaction. Furthermore, an addition of a valence proton particle or hole, through neutron-proton (νπ) interaction, affects the neutron seniority as well as the angular momentum. Purpose: Benchmark the reproducibility of the experimental observables, like the excitation energies (EX) and the reduced electric-quadrupole transition probabilities [B(E2)], with the results obtained from shell-model interactions for neutron-rich Sn and Sb isotopes with N

Published
2019
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16. Production cross section and decay study of Es243 and Md249

Author

J. Rubert, Philippos Papadakis, Pauli Peura, Catherine Scholey, M. Airiau, Rauno Julin, Jan Sarén, Mikael Sandzelius, Jari Partanen, T. Goigoux, A. Drouart, Janne Pakarinen, A. Marchix, R.-D. Herzberg, Tuomas Grahn, T. Calverley, M. Zielińska, B. Sulignano, A. Lopez-Martens, Ulrika Jakobsson, Panu Ruotsalainen, H. Badran, Paul Greenlees, Paivi Nieminen, Ch. Theisen, Juha Sorri, Sakari Juutinen, Juha Uusitalo, Andrej Herzan, F. Dechery, M. Vandebrouck, A. Lightfoot, A. Ward, Kalle Auranen, David Boilley, Sanna Stolze, Matti Leino, B. J. P. Gall, R. Briselet, K. Hauschild, Joonas Konki, F. Defranchi Bisso, A. K. Mistry, Panu Rahkila, and Daniel Cox

Subjects
Nuclear reaction, Physics, Recoil, 010308 nuclear & particles physics, Branching fraction, 0103 physical sciences, Correlation analysis, Atomic physics, 010306 general physics, 01 natural sciences
Abstract

In the study of the odd-$Z$, even-$N$ nuclei $^{243}$Es and $^{249}$Md, performed at the University of Jyv\"askyl\"a, the fusion-evaporation reactions $^{197}$Au($^{48}$Ca,2$n$)$^{243}$Es and $^{203}$Tl($^{48}$Ca,2$n$)$^{249}$Md have been used for the first time. Fusion-evaporation residues were selected and detected using the RITU gas-filled separator coupled with the focal-plane spectrometer GREAT. For $^{243}$Es, the recoil decay correlation analysis yielded a half-life of $24 \pm 3$s, and a maximum production cross section of $37 \pm 10$ nb. In the same way, a half-life of $26 \pm 1$ s, an $\alpha$ branching ratio of 75 $\pm$ 5%, and a maximum production cross section of 300 $\pm$ 80 nb were determined for $^{249}$Md. The decay properties of $^{245}$Es, the daughter of $^{249}$Md, were also measured: an $\alpha$ branching ratio of 54 $\pm$ 7% and a half-life of 65 $\pm$ 6 s. Experimental cross sections were compared to the results of calculations performed using the KEWPIE2 statistical fusion-evaporation code.

Published
2019
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17. 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
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18. Transition probabilities in neutron-rich Se80,82 and the role of the νg9/2 orbital

Author

R. Menegazzo, P. Reiter, R. Lozeva, Suzana Szilner, G. de Angelis, F. Didierjean, A. Blazhev, Begoña Quintana, O. Stézowski, Bo Cederwall, J. Litzinger, C. Fransen, O. Möller, E. Farnea, F. Ibrahim, Ch. Theisen, J. Grebosz, D. Mengoni, Norbert Pietralla, J. Jolie, M. Hackstein, A. M. Stefanini, V. Vandone, D. Verney, P. Désesquelles, P. A. Söderström, E. Sahin, Hans-Jurgen E. Hess, L. Corradi, A. Dewald, B. Million, G. Montagnoli, Roman Gernhäuser, E. Ellinger, A. Gottardo, F. Recchia, J. J. Valiente-Dobón, F. C. L. Crespi, D. Bazzacco, B. Birkenbach, A. Jungclaus, T. Mijatović, V. Modamio, E. Fioretto, Megumi Niikura, M. D. Salsac, Thomas Braunroth, A. Maj, A. Vogt, A. Pullia, F. Scarlassara, Alain Goasduff, S. Leoni, W. Korten, G. Pollarolo, A. Bracco, S. Lunardi, D. Montanari, A. I. Morales, D. R. Napoli, S. Bottoni, J. Eberth, K. Kolos, G. Duchêne, Denise De Rosso, C. Michelagnoli, and Andreas Görgen

Subjects
Physics, 010308 nuclear & particles physics, Yrast, Nuclear structure, Deep inelastic scattering, 01 natural sciences, Particle identification, Nuclear physics, Excited state, 0103 physical sciences, Neutron, AGATA, 010306 general physics, Spin (physics)
Abstract

Transition probabilities of intermediate-spin yrast and non-yrast excitations in 80, 82Se were investigated in a recoil distance Doppler-shift (RDDS) experiment performed at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. The Cologne Plunger device for deep inelastic scattering was used for the RDDS technique and was combined with the AGATA Demonstrator array for the γ-ray detection and coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 80Se, the level lifetimes of the yrast (6+1) and (8+1) states and of a non-yrast band feeding the yrast 4+1 state are determined. A spin and parity assignment of the head of this sideband is discussed based on the experimental results and supported by large-scale shell-model calculations. In 82Se, the level lifetimes of the yrast 6+1 state and the yrare 4+2 state and lifetime limits of the yrast (10+1) state and of the 5−1 state are determined. Although the experimental results contain large uncertainties, they are interpreted with care in terms of large-scale shell-model calculations using the effective interactions JUN45 and jj44b. The excited states' wave functions are investigated and discussed with respect to the role of the neutron g9/2 orbital.

Published
2018
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19. Quadrupole collectivity in Ca42 from low-energy Coulomb excitation with AGATA

Author

D. Mengoni, M. Kisieliński, G. Anil Kumar, M. Kicińska-Habior, D. Karpiński, G. Lehaut, S. F. Özmen, A. Colombo, F. Recchia, R. Menegazzo, J. Iwanicki, F. Azaiez, B. Million, J. Eberth, D. M. Cullen, N. Toniolo, G. Maron, G. de Angelis, M. Krzysiek, O. Stezowski, P. Reiter, B. Birkenbach, D. T. Doherty, M. D. Salsac, P. J. Coleman-Smith, M. Kowalczyk, M. Gulmini, B. Bounthong, J. Srebrny, S. Franchoo, Hans-Jurgen E. Hess, K. Rusek, M. Ciemala, A. Obertelli, J. L. Wood, S. Leoni, H. Naïdja, C. Michelagnoli, A. Giaz, D. Bazzacco, G. Benzoni, J. Styczen, A. Gottardo, L. Berti, R. Wadsworth, E. Farnea, W. Korten, M. Komorowska, F. C. L. Crespi, Ch. Theisen, M. Kmiecik, A. Jungclaus, Megumi Niikura, D. S. Judson, K. Mazurek, S. Brambilla, B. Dulny, T. Abraham, Joël Chavas, Roberto Isocrate, F. Camera, Tomás R. Rodríguez, P. Bednarczyk, I. Stefan, A. Czermak, L. Charles, G. Jaworski, P. Désesquelles, M. Zieblinski, B. Bruyneel, B. Fornal, X. Grave, S. Lunardi, J. Grebosz, N. Kondratyev, Andreas Görgen, K. Wrzosek-Lipska, G. Rampazzo, Pär-Anders Söderström, Marco Bellato, E. Merchan, Andreas Wiens, Alessandra Corsi, T. Habermann, L. Próchniak, P. J. Napiorkowski, M. Zielińska, A. Lopez-Martens, C. A. Ur, B. Wasilewska, K. Hadynska-Klek, Begoña Quintana, D. Rosso, J. Ljungvall, E. Sahin, A. Gadea, A. Korichi, A. Maj, F. Nowacki, P. Cocconi, Alberto Pullia, Bo Cederwall, N. Karkour, Damiano Bortolato, J. J. Valiente Dobon, D. R. Napoli, W. Meczynski, N. Redon, S. Myalski, and M. Palacz

Subjects
Physics, Sideband, 010308 nuclear & particles physics, Coulomb excitation, 01 natural sciences, Matrix (mathematics), Excited state, 0103 physical sciences, Quadrupole, AGATA, Sum rule in quantum mechanics, Atomic physics, 010306 general physics, Beam (structure)
Abstract

A Coulomb-excitation experiment to study electromagnetic properties of Ca42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in Ca42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca42, including the diagonal E2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2+ and 21,2+ states, as well as triaxiality for 01,2+ states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca42.

Published
2018
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20. In-beam spectroscopic study of Cf244

Author

Philippos Papadakis, Catherine Scholey, Tuomas Grahn, Jacek Dobaczewski, Sakari Juutinen, Panu Rahkila, Juha Uusitalo, A. Lightfoot, Daniel Cox, Mikael Sandzelius, M. Leino, Joonas Konki, Sanna Stolze, F. Defranchi Bisso, Kalle Auranen, R-D Herzberg, Yue Shi, Jan Sarén, Andrej Herzan, Rauno Julin, M. Smolen, H. Badran, J. Khuyagbaatar, R. Briselet, B. Sulignano, Ch. Theisen, Juha Sorri, Jari Partanen, Janne Pakarinen, Paul Greenlees, and Helsinki Institute of Physics

Subjects
TOTAL DATA READOUT, Nuclear Theory, chemistry.chemical_element, DEFORMATIONS, 114 Physical sciences, 7. Clean energy, 01 natural sciences, HEAVY-ELEMENTS, NUCLEAR-DATA SHEETS, Atomic orbital, 0103 physical sciences, DETECTORS, medicine, SPECTROMETER, Gamma spectroscopy, Nuclear Experiment, 010306 general physics, GAMMA-RAY SPECTROSCOPY, Physics, Isotope, 010308 nuclear & particles physics, ROTATIONAL BANDS, Californium, Parity (physics), Moment of inertia, medicine.anatomical_structure, chemistry, ISOTOPES, Atomic physics, Nucleon, DECAY, Nucleus
Abstract

The ground-state rotational band of the neutron-deficient californium (Z = 98) isotope 244Cf was identified for the first time and measured up to a tentative spin and parity of I I-pi = 20(+). The observation of the rotational band indicates that the nucleus is deformed. The kinematic and dynamic moments of inertia were deduced from the measured gamma-ray transition energies. The behavior of the dynamic moment of inertia revealed an up-bend due to a possible alignment of coupled nucleons in high-j orbitals starting at a rotational frequency of about (h) over bar (omega) = 0.20 MeV. The results were compared with the systematic behavior of the even-even N = 146 isotones as well as with available theoretical calculations that have been performed for nuclei in the region.

Published
2018
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21. In-beam spectroscopy of heavy elements

Author

T. L. Khoo, Paul Greenlees, P. Chowdhury, Ch. Theisen, and T. Ishii

Subjects
Physics, Nuclear physics, Nuclear reaction, Nuclear and High Energy Physics, Nuclear structure, Superheavy Elements, Spectroscopy, Beam (structure)
Abstract

Traditionally the experimental study of heavy and superheavy elements has belonged to the realm of decay spectroscopy and nuclear reactions. Only in the past twenty years or so has it become feasible to study nuclei with Z = 96 and beyond with in-beam spectroscopic techniques. Since the pioneering studies in the late 1990s, development of both instrumentation and experimental techniques has resulted in a significant lowering of the spectroscopic limit for in-beam measurements. Such measurements give access to a wide range of nuclear structure observables which in general are beyond the reach of other techniques. The current review aims to present the most recent developments and results in the field, building upon previous reviews with a similar theme.

Published
2015
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22. Conceptual design of the AGATA 1$\pi$ array at GANIL

Author

E. Clément, C. Michelagnoli, G. de France, H.J. Li, A. Lemasson, C. Barthe Dejean, M. Beuzard, P. Bougault, J. Cacitti, J.-L. Foucher, G. Fremont, P. Gangnant, J. Goupil, C. Houarner, M. Jean, A. Lefevre, L. Legeard, F. Legruel, C. Maugeais, L. Ménager, N. Ménard, H. Munoz, M. Ozille, B. Raine, J.A. Ropert, F. Saillant, C. Spitaels, M. Tripon, Ph. Vallerand, G. Voltolini, W. Korten, M.-D. Salsac, Ch. Theisen, M. Zielińska, T. Joannem, M. Karolak, M. Kebbiri, A. Lotode, R. Touzery, Ch. Walter, A. Korichi, J. Ljungvall, A. Lopez-Martens, D. Ralet, N. Dosme, X. Grave, N. Karkour, X. Lafay, E. Legay, I. Kojouharov, C. Domingo-Pardo, A. Gadea, R.M. Pérez-Vidal, J.V. Civera, B. Birkenbach, J. Eberth, H. Hess, L. Lewandowski, P. Reiter, A. Nannini, G. De Angelis, G. Jaworski, P. John, D.R. Napoli, J.J. Valiente-Dobón, D. Barrientos, D. Bortolato, G. Benzoni, A. Bracco, S. Brambilla, F. Camera, F.C.L. Crespi, S. Leoni, B. Million, A. Pullia, O. Wieland, D. Bazzacco, S.M. Lenzi, S. Lunardi, R. Menegazzo, D. Mengoni, F. Recchia, M. Bellato, R. Isocrate, F.J. Egea Canet, F. Didierjean, G. Duchêne, R. Baumann, M. Brucker, E. Dangelser, M. Filliger, H. Friedmann, G. Gaudiot, J.-N. Grapton, H. Kocher, C. Mathieu, M.-H. Sigward, D. Thomas, S. Veeramootoo, J. Dudouet, O. Stézowski, C. Aufranc, Y. Aubert, M. Labiche, J. Simpson, I. Burrows, P.J. Coleman-Smith, A. Grant, I.H. Lazarus, P.S. Morrall, V.F.E. Pucknell, A. Boston, D.S. Judson, N. Lalović, J. Nyberg, J. Collado, V. González, I. Kuti, B.M. Nyakó, A. Maj, M. Rudigier, 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), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AGATA, 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), 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), Instituto de Fisica Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universitat de València (UV), University of Cologne, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze (INFN, Sezione di Firenze), Istituto Nazionale di Fisica Nucleare (INFN), INFN Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), 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 Physique Nucléaire d'Orsay (IPNO), Computational Science and Engineering Department [Daresbury] (STFC), Science & Technologie Facilities Council, University of Liverpool, Lund University [Lund], Uppsala University, Department of Electronic Engineering [Universitat Politecnica de Valencia], Universitat Politècnica de València (UPV), Hungarian Academy of Sciences (MTA), Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics, University of Surrey, University of Surrey (UNIS), the EU FEDER funds, MINECO and Generalitat Valenciana, Spain, under the Grants FPA2014-57196-C5, PROMETEOII/2014/019, European Project: 262010,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,ENSAR(2010), and European Project: 654002,H2020,H2020-INFRAIA-2014-2015,ENSAR2(2016)

Subjects
Nuclear and High Energy Physics, Plunger device, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Cyclotron, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Accelerator Physics and Instrumentation, Tracking (particle physics), 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, Conceptual design, law, 0103 physical sciences, PARIS LaBr3 detector, Neutron detection, Pulse shape analysis, AGATA spectrometer, 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Spectrometer, VAMOS plus plus spectrometer, 010308 nuclear & particles physics, Detector, FATIMA LaBr3 detector, Acceleratorfysik och instrumentering, DIAMANT detector, NEDA detector, Author Keywords:AGATA spectrometer, Physics::Accelerator Physics, AGATA, gamma-ray tracking, GANIL facility
Abstract

The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA l π array are presented. Title in WoS: Conceptual design of the AGATA 1 pi array at GANIL

Published
2017
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23. Kr369660 –Low- Z Boundary of the Island of Deformation at N=60

Author

J. Dudouet, A. Lemasson, G. Duchêne, M. Rejmund, E. Clément, C. Michelagnoli, F. Didierjean, A. Korichi, G. Maquart, O. Stezowski, C. Lizarazo, R. M. Pérez-Vidal, C. Andreoiu, G. de Angelis, A. Astier, C. Delafosse, I. Deloncle, Z. Dombradi, G. de France, A. Gadea, A. Gottardo, B. Jacquot, P. Jones, T. Konstantinopoulos, I. Kuti, F. Le Blanc, S. M. Lenzi, G. Li, R. Lozeva, B. Million, D. R. Napoli, A. Navin, C. M. Petrache, N. Pietralla, D. Ralet, M. Ramdhane, N. Redon, C. Schmitt, D. Sohler, D. Verney, D. Barrientos, B. Birkenbach, I. Burrows, L. Charles, J. Collado, D. M. Cullen, P. Désesquelles, C. Domingo Pardo, V. González, L. Harkness-Brennan, H. Hess, D. S. Judson, M. Karolak, W. Korten, M. Labiche, J. Ljungvall, R. Menegazzo, D. Mengoni, A. Pullia, F. Recchia, P. Reiter, M. D. Salsac, E. Sanchis, Ch. Theisen, J. J. Valiente-Dobón, and M. Zielińska

Subjects
Physics, Proton, 010308 nuclear & particles physics, Fission, General Physics and Astronomy, 01 natural sciences, Atomic orbital, Excited state, Neutron number, 0103 physical sciences, Quadrupole, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

Prompt γ-ray spectroscopy of the neutron-rich $^{96}$Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS++ spectrometer. A second excited state, assigned to $J^π$ = $4^+$, is observed for the first time, and a previously reported level energy of the first 2+ excited state is confirmed. The measured energy ratio R4/2 = E($4^+$)/E($2^+$) = 2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N = 60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z = 36, of similar amplitude to that observed at N = 60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g9/2, d5/2, and s1/2 orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R4/2 as a function of the neutron number up to N = 60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N = 60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N = 60 and Z = 36.

Published
2017
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24. Measurement of lifetimes in Fe62,64,Co61,63 , and Mn59

Author

M. Klintefjord, J. Ljungvall, A. Görgen, S. M. Lenzi, F. L. Bello Garrote, A. Blazhev, E. Clément, G. de France, J.-P. Delaroche, P. Désesquelles, A. Dewald, D. T. Doherty, C. Fransen, A. Gengelbach, G. Georgiev, M. Girod, A. Goasduff, A. Gottardo, K. Hadyńska-Klȩk, B. Jacquot, T. Konstantinopoulos, A. Korichi, A. Lemasson, J. Libert, A. Lopez-Martens, C. Michelagnoli, A. Navin, J. Nyberg, R. M. Pérez-Vidal, S. Roccia, E. Sahin, I. Stefan, A. E. Stuchbery, M. Zielińska, D. Barrientos, B. Birkenbach, A. Boston, L. Charles, M. Ciemala, J. Dudouet, J. Eberth, A. Gadea, V. González, L. Harkness-Brennan, H. Hess, A. Jungclaus, W. Korten, R. Menegazzo, D. Mengoni, B. Million, A. Pullia, D. Ralet, F. Recchia, P. Reiter, M. D. Salsac, E. Sanchis, O. Stezowski, Ch. Theisen, and J. J. Valiente Dobon

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Creative commons, 010306 general physics, 01 natural sciences, Engineering physics
Abstract

M. Klintefjord et al. -- 11 pags., 8 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0

Published
2017
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25. Towards saturation of the electron-capture delayed fission probability: The new isotopes $^{240}Es$ and $^{236}Bk$

Author

Rauno Julin, J. Khuyagbaatar, Bettina Lommel, Juha Sorri, Kalle Auranen, R. Briselet, Philippos Papadakis, R-D Herzberg, Paul Greenlees, K. Hauschild, Pauli Peura, J. Krier, Katsuhisa Nishio, Panu Rahkila, S. Juutinen, Sanna Stolze, Joonas Konki, B. Sulignano, Michael Block, Egon Jäger, Ch. Theisen, Mahananda Dasgupta, Alexander Yakushev, Tuomas Grahn, M. J. Mallaburn, Jari Partanen, K. Rezynkina, Janne Pakarinen, A. Ward, Andrej Herzan, Duc Huy Luong, Mikael Sandzelius, David Hinde, V. Yakusheva, Panu Ruotsalainen, Juha Uusitalo, Daniel Cox, A. Di Nitto, Jan Sarén, H. Badran, Ch. E. Düllmann, Birgit Kindler, F. P. Heßberger, A. Lopez-Martens, Matti Leino, C. Scholey, 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), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Konki, J., Khuyagbaatar, J., Uusitalo, J., Greenlees, P. T., Auranen, K., Badran, H., Block, M., Briselet, R., Cox, D. M., Dasgupta, M., Di Nitto, A., Dullmann, C. E., Grahn, T., Hauschild, K., Herzan, A., Herzberg, R. -D., Hessberger, F. P., Hinde, D. J., Julin, R., Juutinen, S., Jager, E., Kindler, B., Krier, J., Leino, M., Lommel, B., Lopez-Martens, A., Luong, D. H., Mallaburn, M., Nishio, K., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rezynkina, K., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Sorri, J., Stolze, S., Sulignano, B., Theisen, C., Ward, A., Yakushev, A., and Yakusheva, V.

Subjects
Electron-capture delayed fission, Nuclear and High Energy Physics, Electron capture, Fission, Fusion–evaporation reaction, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 236 Bk, 01 natural sciences, 7. Clean energy, Recoil separator, Nuclear physics, fusion-evaporation reactions, 236Bk, 240Es, 240 Es, 0103 physical sciences, ddc:530, 010306 general physics, α decay, isotopes, Physics, Isotope, ta114, Isotopes with mass 236–240, 010308 nuclear & particles physics, lcsh:QC1-999, Exponential function, Bk, mass, Atomic physics, Saturation (chemistry), Fusion–evaporation reactions, α particles, lcsh:Physics, Radioactive decay
Abstract

The new neutron-deficient nuclei 240 Es and 236 Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240 Es produced in the fusion–evaporation reaction 209 Bi( 34 S,3n) 240 Es. Half-lives of 6 ( 2 ) s and 22 − 6 + 13 s were obtained for 240 Es and 236 Bk, respectively. Two groups of α particles with energies E α = 8.19 ( 3 ) MeV and 8.09 ( 3 ) MeV were unambiguously assigned to 240 Es. Electron-capture delayed fission branches with probabilities of 0.16 ( 6 ) and 0.04 ( 2 ) were measured for 240 Es and 236 Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

Published
2017
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26. $_{36}^{96}$Kr$_{60}$–low-$Z$ boundary of the island of deformation at $N=60$

Author

J, Dudouet, A, Lemasson, G, Duchêne, M, Rejmund, E, Clément, C, Michelagnoli, F, Didierjean, A, Korichi, G, Maquart, O, Stezowski, C, Lizarazo, R M, Pérez-Vidal, C, Andreoiu, G, de Angelis, A, Astier, C, Delafosse, I, Deloncle, Z, Dombradi, G, de France, A, Gadea, A, Gottardo, B, Jacquot, P, Jones, T, Konstantinopoulos, I, Kuti, F, Le Blanc, S M, Lenzi, G, Li, R, Lozeva, B, Million, D R, Napoli, A, Navin, C M, Petrache, N, Pietralla, D, Ralet, M, Ramdhane, N, Redon, C, Schmitt, D, Sohler, D, Verney, D, Barrientos, B, Birkenbach, I, Burrows, L, Charles, J, Collado, D M, Cullen, P, Désesquelles, C, Domingo Pardo, V, González, L, Harkness-Brennan, H, Hess, D S, Judson, M, Karolak, W, Korten, M, Labiche, J, Ljungvall, R, Menegazzo, D, Mengoni, A, Pullia, F, Recchia, P, Reiter, M D, Salsac, E, Sanchis, Ch, Theisen, J J, Valiente-Dobón, and M, Zielińska

Subjects
Nuclear Physics - Experiment
Abstract

Prompt γ-ray spectroscopy of the neutron-rich ^{96}Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS++ spectrometer. A second excited state, assigned to J^{π}=4^{+}, is observed for the first time, and a previously reported level energy of the first 2^{+} excited state is confirmed. The measured energy ratio R_{4/2}=E(4^{+})/E(2^{+})=2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N=60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z=36, of similar amplitude to that observed at N=60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g_{9/2}, d_{5/2}, and s_{1/2} orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R_{4/2} as a function of the neutron number up to N=60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N=60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N=60 and Z=36.

Published
2017

27. Nuclear structure features of very heavy and superheavy nuclei—tracing quantum mechanics towards the ‘island of stability’

Author

Dieter Ackermann, Ch. Theisen, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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, Proton, 010308 nuclear & particles physics, Nuclear Theory, Nuclear structure, Transactinide element, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Condensed Matter Physics, Nuclear matter, 7. Clean energy, 01 natural sciences, Atomic and Molecular Physics, and Optics, Island of stability, Nuclear physics, Neutron star, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, Mathematical Physics
Abstract

International audience; The quantum-mechanic nature of nuclear matter is at the origin of the vision of a region ofenhanced stability at the upper right end of the chart of nuclei, the so-called ‘island of stability’.Since the 1960s in the early second half of the last century, various models predict closed shellsfor proton numbers 114–126 and neutron numbers such as 172 or 184. Being stabilized byquantum-mechanic effects only, those extremely heavy man-made nuclear species are an ideallaboratory to study the origin of the strong nuclear interaction which is the driving force formatter properties in many fields ranging from microscopic scales like hadronic systems tocosmic scales in stellar environments like neutron stars. Since the 1950s, experiments onthe synthesis of new elements and isotopes have also revealed various exciting nuclear structurefeatures. The contribution of Bohr, Mottelson and Rainwater with, in particular, the developmentof the unified model played an essential role in this context. Although not anticipated inthe region of the heaviest nuclei, many phenomena were subsequently discovered like theinterplay of collective features manifesting themselves e.g. in nuclear deformation, ranging fromspherical to prolate and oblate shapes with the possible occurrence of triaxial symmetries, andsingle particle states and their excitation into quasiparticle configurations. The continuousdevelopment of modern experimental techniques employing advanced detection set-ups wasessential to reveal these exciting nuclear structure aspects in the actinide and transactinideregions since the production cross-section becomes extremely small with increasing mass andcharge. Further technological progress, in particular, high intensity stable ion beam acceleratorfacilities presently under construction, as well as potentially in the farther future radioactiveneutron rich ion beams provide a high discovery potential for the basic understanding of nuclearmatter.

Published
2017
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28. SIRIUS project (spectroscopy & identification of rare isotopes using S3)

Author

N. Karkour, Ch. Theisen, Y. Moudden, K. Hauschild, G. Lebertre, B. Gall, X. Lafay, S. Coudert, H. Savagols, A. Lopez-Martens, D. Linget, A. Boujrad, F. Dechery, B. Sulignano, P. Brionnet, J. Piot, F. Saillant, F. Le Blanc, T. Goeltzenlichter, L. Gibelin, G. Wittwer, M. Tripon, M. Authier, Th. Lefrou, O. Dorvaux, V. Alaphilippe, A. Drouart, C. Maugeais, S. Herlant, Ch. Spitaels, J. Pancin, F. Lutton, E. Delagnes, L. Legeard, C. Mathieu, and Th. Chaminade

Subjects
Physics, Silicon, Spectrometer, Physics::Instrumentation and Detectors, Preamplifier, Detector, chemistry.chemical_element, 020206 networking & telecommunications, Germanium, 02 engineering and technology, 7. Clean energy, 030218 nuclear medicine & medical imaging, Nuclear physics, 03 medical and health sciences, 0302 clinical medicine, Cardinal point, chemistry, 0202 electrical engineering, electronic engineering, information engineering, Nuclear Experiment, Spectroscopy, Radioactive decay
Abstract

SIRIUS is a state-of-the-art detector system for nuclear decay spectroscopy that will be mounted at the focal plane of S3 (Super Separator Spectrometer), which is part of the new SPIRAL2 facility at GANIL, Caen in France. Such a system requires high performance as it is dedicated to the study of very exotic nuclei. It is the result of collaboration between GANIL CSNSM, IRFU, and IPHC It is composed of a succession of detectors (Trackers, Silicon detector DSSD and Tunnel plus an array of five clover Germanium detectors). This set-up is mounted in a compact geometry. The energy measurement varies from 50 keV to over 500 MeV with high precision (2 × 10−3) at low energies and 1 % for the detection of heavy ions. A major challenge has been the development of new electronics with a very large dynamic range maintaining an adequate energy resolution for the measured particles (with energies from a few hundred keV up to 500 MeV).

Published
2016
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29. Superdeformed and Triaxial States in Ca 42

Author

G. Benzoni, Bo Cederwall, M. Komorowska, Begoña Quintana, D. Rosso, J. Styczen, Damiano Bortolato, J. J. Valiente Dobon, P. Bednarczyk, L. Charles, M. Ziȩbliński, W. Korten, R. Nicolini, L. Próchniak, P. Reiter, D. R. Napoli, T. Habermann, A. Maj, A. Gottardo, L. Berti, A. Lopez-Martens, G. Rampazzo, J. L. Wood, F. Nowacki, P. J. Coleman-Smith, C. Michelagnoli, B. Bounthong, S. Franchoo, P. Cocconi, T. Abraham, J. Ljungvall, Marco Bellato, M. Kicińska-Habior, P. Désesquelles, G. Anil Kumar, J. Mierzejewski, N. Kondratyev, K. Hadyńska-Klȩk, A. Korichi, P. A. Söderström, E. Sahin, Agnese Giaz, M. Kisieliński, F. Recchia, Benedicte Million, X. Grave, A. Gadea, N. Toniolo, S. F. Özmen, G. Maron, O. Stezowski, D. Karpiński, E. Farnea, S. Lunardi, S. Leoni, H. Naïdja, M. Palacz, J. Srebrny, D. Bazzacco, J. Iwanicki, F. Azaiez, B. Dulny, Joël Chavas, Roberto Isocrate, Alberto Pullia, G. Jaworski, P. J. Napiorkowski, J. Eberth, M. Gulmini, M. Kmiecik, Megumi Niikura, G. de Angelis, V. Vandone, M. Krzysiek, N. Karkour, F. C. L. Crespi, I. Stefan, B. Bruyneel, Ch. Theisen, M. Ciemala, A. Obertelli, M. Zielinska, Andrea Corsi, D. M. Cullen, B. Fornal, R. Menegazzo, C. A. Ur, K. Rusek, R. Wadsworth, A. Colombo, S. Myalski, G. Lehaut, A. Jungclaus, M. Kowalczyk, A. Czermak, W. Mȩczyński, B. Birkenbach, D. T. Doherty, M. D. Salsac, D. S. Judson, K. Mazurek, J. Grȩbosz, D. Mengoni, Tomás R. Rodríguez, B. Wasilewska, S. Brambilla, F. Camera, Andreas Görgen, E. Merchan, Andreas Wiens, K. Wrzosek-Lipska, Herbert Hess, N. Redon, European Commission, Federal Ministry of Education and Research (Germany), National Science Centre (Poland), Generalitat Valenciana, Nuclear Astrophysics Virtual Institute (Germany), Helmholtz Association, Ministerio de Economía y Competitividad (España), Research Council of Norway, Laboratori Nazionali di Legnaro, Helmholtz Centre for Heavy Ion Research, and University of Warsaw

Subjects
Physics, Sideband, 010308 nuclear & particles physics, SHELL model, Nuclear Theory, General Physics and Astronomy, Coulomb excitation, 7. Clean energy, 01 natural sciences, Superdeformation, Matrix (mathematics), Physics and Astronomy (all), 0103 physical sciences, AGATA, Atomic physics, 010306 general physics
Abstract

K. Hadyńska-Kl¸ek et al. ; 7 pags., 3 figs., 2 tabs., Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42 were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 02+ has been obtained and the role of triaxiality in the A∼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time. © 2016 American Physical Society, Special gratitude goes to the INFN LNL and HIL Warsaw technical staff for their support and help, in particular, the accelerator crews for providing intense and good-quality 42Ca and 32S beams. K. H.-K. acknowledges support from the Research Council of Norway under the project Grant No. 213442. T. R. R. acknowledges computing time at GSI-Darmstadt and support from Spanish MINECO under Programa Ramon y Cajal 11420 and FIS-2014-53434-P, H. N. acknowledges support from Helmholtz Association through the Nuclear Astrophysics Virtual Institute NAVI (No. VH-VI-417). We also acknowledge the support by Generalitat Valenciana, Spain, under the grant PROMETEOII/2014/019 and by the FEDER funds of the European Commission (A. Gadea), Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5 (A. J., A. Gadea), German Bundesministerium für Bildung und Forschung (BMBF) under Contract No. 05P12PKFNE TP4 (B. Birkenbach), the Polish National Science Centre under Projects No. DEC-2013/10/M/ST2/00427, No. DPN/N190/ AGATA/2009, No. 2011/03/B/ST2/01894, No. UMO- 2014/14/M/ST2/00738 (COPIN-INFN Collaboration), and No. 2015/17/B/ST2/01534.

Published
2016
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30. Isospin Mixing inZr80: From Finite to Zero Temperature

Author

S. Brambilla, S. Leoni, D. Bazzacco, P. Désesquelles, Stefano Riboldi, D. S. Judson, P. Reiter, O. Stezowski, G. Benzoni, Herbert Hess, R. Menegazzo, R. Avigo, F. C. L. Crespi, M. Ciemala, F. Camera, E. Farnea, M. Kmiecik, Andreas Görgen, G. Bocchi, J. J. Valiente-Dobón, F. Recchia, R. Nicolini, D. Montanari, P. A. Söderström, B. Birkenbach, J. Eberth, M. Zieblinski, V. Modamio, S. Myalski, Luna Pellegri, B. Million, A. Mentana, A. Jungclaus, S. Bottoni, C. A. Ur, W. Korten, D. R. Napoli, Ch. Theisen, N. Blasi, S. Ceruti, A. Bracco, A. Pullia, A. Giaz, A. Maj, A. Gottardo, O. Wieland, D. Mengoni, E. Sahin, M.D. Salsac, Begoña Quintana, D. Rosso, A. I. Morales, and C. Michelagnoli

Subjects
Physics, 010308 nuclear & particles physics, Nuclear Theory, Gamma ray, General Physics and Astronomy, Resonance, 7. Clean energy, 01 natural sciences, Nuclear physics, Dipole, Isospin, 0103 physical sciences, AGATA, Atomic physics, Nuclear Experiment, 010306 general physics, Mixing (physics), Excitation, Fermi Gamma-ray Space Telescope
Abstract

The isospin mixing was deduced in the compound nucleus Zr-80 at an excitation energy of E* = 54 MeV from the gamma decay of the giant dipole resonance. The reaction Ca-40 + Ca-40 at E-beam = 136 MeV was used to form the compound nucleus in the isospin I = 0 channel, while the reaction Cl-37 + Ca-44 at E-beam = 95 MeV was used as the reference reaction. The. rays were detected with the AGATA demonstrator array coupled with LaBr3:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction delta(C) used for the Fermi superallowed transitions was extracted and found to be consistent with beta-decay data.

Published
2015
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31. Population of the2ms+mixed-symmetry state ofBa140with theα-transfer reaction

Author

A. Gadea, W. Korten, D. Mengoni, P. A. Söderström, S. Lunardi, C. Michelagnoli, G. de Angelis, A. Goergen, V. Modamio, Hans-Jurgen E. Hess, D. Bazzacco, S. M. Lenzi, A. Pullia, J. Leske, J. Eberth, D. R. Napoli, M. Reese, F. C. L. Crespi, R. Menegazzo, C. A. Ur, P. Reiter, E. Farnea, Ch. Theisen, J. Jolie, B. Birkenbach, A. Bracco, P. Désesquelles, P. R. John, C. Bauer, J. J. Valiente-Dobón, J. Grebosz, A. Gottardo, A. Jungclaus, M. D. Salsac, Begoña Quintana, Norbert Pietralla, D. Rosso, C. Stahl, O. Stezowski, E. Sahin, and F. Recchia

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, Isovector, Proton, 010308 nuclear & particles physics, Population, State (functional analysis), 01 natural sciences, Inelastic neutron scattering, 0103 physical sciences, Atomic nucleus, Interacting boson model, Atomic physics, 010306 general physics, Spectroscopy, education
Abstract

Background: Identification of proton-neutron mixed-symmetric one-quadrupole phonon excitations (the 2(ms)(+) states) of atomic nuclei provides information on the isovector part of the residual nucleon-nucleon interaction. It was predicted that the 2(ms)(+) state of particular nuclei close to the U(5) limit of the interacting boson model, in particular Ba-140, should be considerably populated by alpha-transfer reactions [C. E. Alonso et al., Phys. Rev. C 78, 017301 (2008)]. Purpose: We aim at the identification of the 2(ms)(+) mixed-symmetry state (MSS) of radioactive Ba-140 and investigate its population by the alpha-transfer reaction as a suitable tool to selectively populate MSSs and as a potential new signature for its mixed-symmetric character. Method: A gamma-ray spectroscopy experiment was performed in inverse kinematics in order to populate the 2(ms)(+) state of Ba-140 by alpha-transfer from a C-nat target on Xe-136 beam ions. The population of the candidate for the 2(ms)(+) state of Ba-140 was measured relative to the population of the 2(1)(+) state. Results: The candidate for the 2(ms)(+) state of Ba-140 was populated by a transfer three times weaker than predicted. Another 2(+) state that can be ruled out as the MSS was in turn as strongly populated by the a transfer as predicted for the MSS. Conclusions: The relative population of 2(+) states by alpha-transfer cannot serve as a new signature for MSSs, since other 2(+) states are also strongly populated. Nevertheless, the substantial population of the MSS candidate of Ba-140 by alpha transfer qualifies this type of reaction as suitable tool to excite MSSs and study their electromagnetic decay properties.

Published
2015
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32. Spectroscopy of the neutron-rich actinide nucleusU240following multinucleon-transfer reactions

Author

A. Gengelbach, S. M. Lenzi, Begoña Quintana, Suzana Szilner, B. Szpak, F. C. L. Crespi, D. Rosso, Andreas Wiens, D. Mengoni, R. Menegazzo, T. Steinbach, Luna Pellegri, B. Birkenbach, S. Leoni, M. Bowry, Alberto Pullia, Herbert Hess, C. A. Ur, W. Korten, E. Fioretto, C. Michelagnoli, A. M. Stefanini, J. Eberth, O. Stezowski, M. D. Salsac, F. Scarlassara, F. Radeck, D. Bazzacco, S. Lunardi, G. Pollarolo, E. Farnea, D. Montanari, E. Sahin, Ch. Theisen, J. Grebosz, A. Jungclaus, T. Mijatović, Andreas Görgen, A. Gadea, A. Bracco, L. Corradi, P. Reiter, P. R. John, J. J. Valiente-Dobón, D. R. Napoli, K. Geibel, A. Gottardo, Agnese Giaz, J. Jolie, G. de Angelis, P. A. Söderström, G. Montagnoli, A. Vogt, B. Bruyneel, P. Désesquelles, D. S. Judson, F. Recchia, and V. Vandone

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Nuclear Theory, Nuclear structure, Moment of inertia, 01 natural sciences, 7. Clean energy, Coincidence, Semiconductor detector, Nuclear physics, 0103 physical sciences, Neutron, AGATA, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

Background: Nuclear structure information for the neutron-rich actinide nuclei is important since it is the benchmark for theoretical models that provide predictions for the heaviest nuclei. Purpose: gamma-ray spectroscopy of neutron-rich heavy nuclei in the actinide region. Method: Multinucleon-transfer reactions in Zn-70 + U-238 and Xe-136 + U-238 have been measured in two experiments performed at the INFN Legnaro, Italy. In the Zn-70 experiment the high-resolution HPGe Clover Array (CLARA) coupled to the magnetic spectrometer PRISMA was employed. In the Xe-136 experiment the high-resolution Advanced Gamma Tracking Array (AGATA) was used in combination with PRISMA and the Detector Array for Multinucleon Transfer Ejectiles (DANTE). Results: The ground-state band (g.s. band) of U-240 was measured up to the 20(+) level and a tentative assignment was made up to the (24(+)) level. Results from gamma gamma coincidence and from particle coincidence analyses are shown. Moments of inertia (MoI) show a clear upbend. Evidence for an extended first negative-parity band of U-240 is found. Conclusions: A detailed comparison with latest calculations shows best agreement with cranked relativistic Hartree-Bogoliubov (CRHB) calculations for the g.s. band properties. The negative-parity band shows the characteristics of a K-pi = 0 band based on an octupole vibration.

Published
2015
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33. Lifetime measurments of excited states in neutron-rich fission fragments

Author

T.W. Hagen, L. Grente, A. Görgen, M.-D. Salsac, W. Korten, F. Farget, T. Braunroth, B. Bruyneel, I. Celikovic, E. Clément, G. de France, O. Delaune, A. Dewald, A. Dijon, M. Hackstein, B. Jacquot, J. Litzinger, J. Ljungvall, C. Louchart, C. Michelagnoli, D.R. Napoli, A. Navin, F. Recchia, M. Rejmund, W. Rother, E. Sahin, S. Siem, B. Sulignano, Ch. Theisen, J.J. Valiente-Dobon, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (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 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), 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 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)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM)

Subjects
Physics, Spectrometer, 010308 nuclear & particles physics, Fission, Gamma ray, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, symbols.namesake, Physics and Astronomy (all), Recoil, Excited state, 0103 physical sciences, symbols, Neutron, Atomic number, Atomic physics, Nuclear Experiment, Doppler effect
Abstract

Expérience GANIL/VAMOS/EXOGAM; International audience; Lifetimes of short-lived excited states in a wide range of neutron-richfission fragments were measured using the recoil distance Doppler shift(RDDS) technique, which was applied to fusion-fission reactions in inversekinematics for the first time. The fission fragments were identified eventby-event in mass, charge, and atomic number using the VAMOS magneticspectrometer at GANIL. Gamma rays originating from the fission fragmentswere measured with the EXOGAM array of Ge Clover detectors aroundthe target position. Using a degrader, the change in the Doppler shiftof the $\gamma$ ray allows the application of the RDDS method. Details of theexperimental technique will be discussed and the status for the ongoinganalysis for odd-mass yttrium isotopes will be presented.

Published
2015
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34. Light and heavy transfer products inXe136+U238multinucleon transfer reactions

Author

A. Gengelbach, B. Szpak, Andreas Wiens, W. Korten, A. Gadea, Begoña Quintana, J. Grebosz, P-A Soderstrom, G. de Angelis, F. Radeck, D. Rosso, B. Birkenbach, G. Montagnoli, Alberto Pullia, E. Sahin, M. D. Salsac, G. Pollarolo, J. Jolie, S. Lunardi, Suzana Szilner, D. Montanari, A. M. Stefanini, D. Bazzacco, E. Fioretto, A. Jungclaus, P. Reiter, L. Corradi, O. Stezowski, D. R. Napoli, K. Geibel, B. Bruyneel, M. Bowry, Andreas Görgen, V. Vandone, Luna Pellegri, E. Farnea, Ch. Theisen, C. A. Ur, Tea Mijatović, F. Scarlassara, P. Désesquelles, P. R. John, J. Eberth, J. J. Valiente-Dobón, D. Mengoni, S. Leoni, A. Bracco, A. Vogt, F. Recchia, A. Giaz, A. Gottardo, R. Menegazzo, T. Steinbach, F. C. L. Crespi, C. Michelagnoli, Hans-Jurgen E. Hess, and D. S. Judson

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, Spectrometer, Fission, Scattering, Neutron emission, Nuclear Theory, Population, Nuclear structure, 7. Clean energy, Nuclear physics, AGATA, Atomic physics, Nuclear Experiment, Nucleon, education
Abstract

Background: Multinucleon transfer reactions (MNT) are a competitive tool to populate exotic neutron-rich nuclei in a wide region of nuclei, where other production methods have severe limitations or cannot be used at all. Purpose: Experimental information on the yields of MNT reactions in comparison with theoretical calculations are necessary to make predictions for the production of neutron-rich heavy nuclei. It is crucial to determine the fraction of MNT reaction products which are surviving neutron emission or fission at the high excitation energy after the nucleon exchange. Method: Multinucleon transfer reactions in Xe-136 + U-238 have been measured in a high-resolution gamma-ray/particle coincidence experiment. The large solid-angle magnetic spectrometer PRISMA coupled to the high-resolution Advanced Gamma Tracking Array (AGATA) has been employed. Beamlike reaction products after multinucleon transfer in the Xe region were identified and selected with the PRISMA spectrometer. Coincident particles were tagged by multichannel plate detectors placed at the grazing angle of the targetlike recoils inside the scattering chamber. Results: Mass yields have been extracted and compared with calculations based on the GRAZING model for MNT reactions. Kinematic coincidences between the binary reaction products, i.e., beamlike and targetlike nuclei, were exploited to obtain population yields for nuclei in the actinide region and compared to x-ray yields measured by AGATA. Conclusions: No sizable yield of actinide nuclei beyond Z = 93 is found to perform nuclear structure investigations. In-beam gamma-ray spectroscopy is feasible for few-neutron transfer channels in U and the -2p channel populating Th isotopes.

Published
2015
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35. Shell evolution beyondN=40:Cu69,71,73

Author

E. Sahin, M. Doncel, K. Sieja, G. de Angelis, A. Gadea, B. Quintana, A. Görgen, V. Modamio, D. Mengoni, J. J. Valiente-Dobón, P. R. John, M. Albers, D. Bazzacco, G. Benzoni, B. Birkenbach, B. Cederwall, E. Clément, D. Curien, L. Corradi, P. Désesquelles, A. Dewald, F. Didierjean, G. Duchêne, J. Eberth, M. N. Erduran, E. Farnea, E. Fioretto, G. de France, C. Fransen, R. Gernhäuser, A. Gottardo, M. Hackstein, T. Hagen, A. Hernández-Prieto, H. Hess, T. Hüyük, A. Jungclaus, S. Klupp, W. Korten, A. Kusoglu, S. M. Lenzi, J. Ljungvall, C. Louchart, S. Lunardi, R. Menegazzo, C. Michelagnoli, T. Mijatović, B. Million, P. Molini, G. Montagnoli, D. Montanari, O. Möller, D. R. Napoli, A. Obertelli, R. Orlandi, G. Pollarolo, A. Pullia, F. Recchia, P. Reiter, D. Rosso, W. Rother, M.-D. Salsac, F. Scarlassara, M. Schlarb, S. Siem, Pushpendra P. Singh, P.-A. Söderström, A. M. Stefanini, O. Stézowski, B. Sulignano, S. Szilner, Ch. Theisen, C. A. Ur, and M. Yalcinkaya

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, 0103 physical sciences, Shell (structure), 010306 general physics, 01 natural sciences, Molecular physics
Published
2015
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36. 1−and2+discrete states inZr90populated via the(O17,O′17γ)reaction

Author

R. Menegazzo, Luna Pellegri, G. de Angelis, C. A. Ur, V. Vandone, M. Krzysiek, R. Nicolini, C. Michelagnoli, A. Vitturi, D. Bazzacco, M. Ciemala, J. J. Valiente-Dobón, D. R. Napoli, P. Désesquelles, R.S. Kempley, Marco Bellato, B. Birkenbach, E. G. Lanza, S. Brambilla, Bo Cederwall, S. Leoni, P. Reiter, J. Jolie, M. Kmiecik, A. Gadea, A. Giaz, Andrea Corsi, Damiano Bortolato, F. Camera, O. Wieland, A. Gottardo, D. Mengoni, F. C. L. Crespi, Herbert Hess, A. Jungclaus, A. Maj, A. Bracco, M. Labiche, A. Pullia, E. Farnea, Ch. Theisen, Sunniva Siem, G. Benzoni, B. Million, A. Goergen, Begoña Quintana, F. Recchia, Roberto Isocrate, C. Boiano, J. Eberth, S. Bottoni, P. A Soederstroem, N. Blasi, P. Molini, Enrico Calore, E. Sahin, O. Stezowski, and P. Bednarczyk

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Isoscalar, Nuclear Theory, Gamma ray, High resolution, 01 natural sciences, 7. Clean energy, 0103 physical sciences, AGATA, Atomic physics, Born approximation, 010306 general physics, Excitation
Abstract

2(+) and 1(-) states in Zr-90 were populated via the (O-17, O-17 'gamma) reaction at 340 MeV. The gamma decay was measured with high resolution using the AGATA (advanced gamma tracking array demonstrator array). Differential cross sections were obtained at few different angles for the scattered particle. The results of the elastic scattering and inelastic excitation of 2(+), 3(,)(-) and 1(-) states are compared with distorted-wave Born approximation (DWBA) calculations, using both the standard collective form factor and a form factor obtained by folding microscopically calculated transition densities. This allowed to extract the isoscalar component of the 1(-) state at 6.424 MeV. The comparison of the present (17O, 17O 'gamma) data with existing (gamma,gamma') and (p, p') data in the corresponding region of the gamma continuum (6-11 MeV), characterized by a large E1 component, shows completely different behaviors of the cross section as a function of the nuclear excitation energy. The comparison of the data with DWBA calculations suggests a decrease of the isoscalar strength in the cross section with increasing excitation energy.

Published
2015
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38. Carbonate fabrics in the modern microbialites of Pavilion Lake: two suites of microfabrics that reflect variation in microbial community morphology, growth habit, and lithification.

Author

Theisen CH, Sumner DY, Mackey TJ, Lim DS, Brady AL, and Slater GF

Subjects
British Columbia, Chlorophyta ultrastructure, Cyanobacteria ultrastructure, Fossils anatomy & histology, Fossils microbiology, Microscopy, Electron, Scanning, Carbonates chemistry, Chlorophyta growth & development, Cyanobacteria growth & development, Geologic Sediments microbiology, Lakes microbiology
Abstract

Modern microbialites in Pavilion Lake, BC, provide an analog for ancient non-stromatolitic microbialites that formed from in situ mineralization. Because Pavilion microbialites are mineralizing under the influence of microbial communities, they provide insights into how biological processes influence microbialite microfabrics and mesostructures. Hemispherical nodules and micrite-microbial crusts are two mesostructures within Pavilion microbialites that are directly associated with photosynthetic communities. Both filamentous cyanobacteria in hemispherical nodules and branching filamentous green algae in micrite-microbial crusts were associated with calcite precipitation at microbialite surfaces and with characteristic microfabrics in the lithified microbialite. Hemispherical nodules formed at microbialite surfaces when calcite precipitated around filamentous cyanobacteria with a radial growth habit. The radial filament pattern was preserved within the microbialite to varying degrees. Some subsurface nodules contained well-defined filaments, whereas others contained only dispersed organic inclusions. Variation in filament preservation is interpreted to reflect differences in timing and amount of carbonate precipitation relative to heterotrophic decay, with more defined filaments reflecting greater lithification prior to degradation than more diffuse filaments. Micrite-microbial crusts produce the second suite of microfabrics and form in association with filamentous green algae oriented perpendicular to the microbialite surface. Some crusts include calcified filaments, whereas others contained voids that reflect the filamentous community in shape, size, and distribution. Pavilion microbialites demonstrate that microfabric variation can reflect differences in lithification processes and microbial metabolisms as well as microbial community morphology and organization. Even when the morphology of individual filaments or cells is not well preserved, the microbial growth habit can be captured in mesoscale microbialite structures. These results suggest that when petrographic preservation is extremely good, ancient microbialite growth structures and microfabrics can be interpreted in the context of variation in community organization, community composition, and lithification history. Even in the absence of distinct microbial microfabrics, mesostructures can capture microbial community morphology., (© 2015 John Wiley & Sons Ltd.)

Published
2015
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