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127 results on '"S, Leoni"'

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

Author

S. Ziliani, M. Ciemała, F.C.L. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S.M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D.R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Ziębliński, M. Zielińska, Ziliani, S., Ciemała, M., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clément, E., Coelli, S., Dorvaux, O., Erturk, S., de France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, Ł. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Müller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, Ch., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), ILL, and Research unit Nuclear & Hadron Physics

Subjects
Physics, education.field_of_study, Spectrometer, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Population, Gamma ray, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Excited state, 0103 physical sciences, Neutron, AGATA, 010306 general physics, Spectroscopy, education, Beam (structure)
Abstract

Excited states of 17N, 18N and 19N were investigated through the measurement of gamma rays, following their population via deep-inelastic reactions induced by an 18O beam (7 MeV/u) on a thick 181Ta target. The experimental setup comprised the AGATA+PARIS detection system, coupled to the VAMOS++ magnetic spectrometer. In the 17N nucleus, the analysis of gamma-ray transitions de-exciting two states around 4-5 MeV clearly pointed to discrepancies with the lifetime values reported in literature. Three new gamma rays were observed in 18N at the energies of 1662.3 (3) keV, 2073.4 (8) keV and 2300.9 (8) keV, and hints for other two new transitions around 1566 keV and 1720 keV were found. In addition, a new transition with energy of 2489.7 (8) keV was observed in 19N.

Published
2020

2. 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

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

Author

S. Ziliani, M. Ciemała, F. C. L. Crespi, S. Leoni, B. Fornal, T. Suzuki, T. Otsuka, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M. N. Harakeh, Ł. W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S. M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D. R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Ziębliński, M. Zielińska, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Set (abstract data type), Physics, Particle physics, medicine.anatomical_structure, 010308 nuclear & particles physics, 0103 physical sciences, medicine, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Parity (mathematics), 01 natural sciences, Nucleus
Abstract

International audience; High-resolution γ-ray spectroscopy of N18 is performed with the Advanced GAmma Tracking Array, following deep-inelastic processes induced by an O18 beam on a Ta181 target. Six states are newly identified, which together with the three known excitations exhaust all negative-parity excited states expected in N18 below the neutron threshold. Spin and parities are proposed for all located states on the basis of decay branchings and comparison with large-scale shell-model calculations performed in the p-sd space, with the YSOX interaction. Of particular interest is the location of the 01− and 12− excitations, which provide strong constrains for cross-shell p-sd matrix elements based on realistic interactions and help to simultaneously reproduce the ground and first-excited states in N16 and N18, for the first time. Understanding the N18 structure may also have significant impact on neutron-capture cross-section calculations in r-process modeling including light neutron-rich nuclei.

Published
2021

4. Evidence for enhanced neutron-proton correlations from the level structure of the N=Z+1 nucleus Tc444387

Author

X. Liu, B. Cederwall, C. Qi, R. A. Wyss, Ö. Aktas, A. Ertoprak, W. Zhang, E. Clément, G. de France, D. Ralet, A. Gadea, A. Goasduff, G. Jaworski, I. Kuti, B. M. Nyakó, J. Nyberg, M. Palacz, R. Wadsworth, J. J. Valiente-Dobón, H. Al-Azri, A. Ataç Nyberg, T. Bäck, G. de Angelis, M. Doncel, J. Dudouet, A. Gottardo, M. Jurado, J. Ljungvall, D. Mengoni, D. R. Napoli, C. M. Petrache, D. Sohler, J. Timár, D. Barrientos, P. Bednarczyk, G. Benzoni, B. Birkenbach, A. J. Boston, H. C. Boston, I. Burrows, L. Charles, M. Ciemala, F. C. L. Crespi, D. M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Eberth, N. Erduran, S. Ertürk, V. González, J. Goupil, H. Hess, T. Huyuk, A. Jungclaus, W. Korten, A. Lemasson, S. Leoni, A. Maj, R. Menegazzo, B. Million, R. M. Perez-Vidal, Zs. Podolyàk, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, J. Simpson, O. Stezowski, C. Theisen, and M. Zielińska

Subjects
Physics, Proton, Spectrometer, 010308 nuclear & particles physics, Isoscalar, Nuclear Theory, 01 natural sciences, Charged particle, Excited state, 0103 physical sciences, Level structure, Neutron, AGATA, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

The low-lying excited states in the neutron-deficient $N = Z + 1$ nucleus $^{87}_{43}$Tc$_{44}$ have been studied via the fusion-evaporation reaction $^{54}$Fe $(^{36}Ar, 2n1p)$ $^{87}$Tc at the Grand Accelerateur National d'Ions Lourds (GANIL), France. The AGATA spectrometer was used in conjunction with the auxiliary NEDA, Neutron Wall, and DIAMANT detector arrays to measure coincident prompt γ rays, neutrons, and charged particles emitted in the reaction. A level scheme of $^{87}$Tc from the $(9/2^+_{g.s})$ state to the $( 33 / 2^+_1$) state was established based on six mutually coincident γ -ray transitions. The constructed level structure exhibits a rotational behavior with a sharp backbending at $ℏω ≈ 0.50$ MeV. A decrease in alignment frequency and increase in alignment sharpness in the odd-mass isotonic chains around $N=44$ is proposed as an effect of the enhanced isoscalar neutron-proton interactions in odd-mass nuclei when approaching the $N=Z$ line.

Published
2021

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

Author

M. Zieblinski, J. Grebosz, K. Mazurek, Simone Coelli, S. Brambilla, H. J. Li, B. Million, M. Rejmund, Bertrand Jacquot, P. Bednarczyk, N. Cieplicka-Oryńczak, M. Ciemala, M. Bast, S. Ziliani, O. Dorvaux, S. Erturk, Eric Clément, Ł. W. Iskra, C. Fransen, S. M. Lenzi, B. Fornal, P. J. Napiorkowski, C. Müller-Gatermann, M. Zielińska, B. Wasilewska, I. Matea, A. Maj, M. Kmiecik, Y. H. Kim, M. Kicińska-Habior, C. Michelagnoli, I. Stefan, M. Beckers, F. C. L. Crespi, O. Wieland, M. Lewitowicz, R. Palit, D. R. Napoli, Ch. Schmitt, A. V. Karpov, M. Stanoiu, F. Camera, Emanuele Vardaci, M. Matejska-Minda, A. Bracco, G. Benzoni, S. Bottoni, S. Leoni, V. Nanal, C. Boiano, A. Lemasson, Mohsen Harakeh, Thomas Braunroth, A. Goldkuhle, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ciemala, M., Ziliani, S., Crespi, F. C. L., Leoni, S., Fornal, B., Maj, A., Bednarczyk, P., Benzoni, G., Bracco, A., Boiano, C., Bottoni, S., Brambilla, S., Bast, M., Beckers, M., Braunroth, T., Camera, F., Cieplicka-Orynczak, N., Clement, E., Coelli, S., Dorvaux, O., Erturk, S., De France, G., Fransen, C., Goldkuhle, A., Grebosz, J., Harakeh, M. N., Iskra, L. W., Jacquot, B., Karpov, A., Kicinska-Habior, M., Kim, Y. -H., Kmiecik, M., Lemasson, A., Lenzi, S. M., Lewitowicz, M., Li, H., Matea, I., Mazurek, K., Michelagnoli, C., Matejska-Minda, M., Million, B., Muller-Gatermann, C., Nanal, V., Napiorkowski, P., Napoli, D. R., Palit, R., Rejmund, M., Schmitt, C., Stanoiu, M., Stefan, I., Vardaci, E., Wasilewska, B., Wieland, O., Zieblinski, M., Zielinska, M., H. Niewodniczanski Institute of Nuclear Physics, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Dipartimento di Fisica (Milano), Università degli Studi di Milano [Milano] (UNIMI), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Institut für Kernphysik der Universität zu Köln, Universität zu Köln, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Milano = University of Milan (UNIMI), Universität zu Köln = University of Cologne, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Nuclear Energy

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Monte Carlo method, Hadron, FOS: Physical sciences, Binary number, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Excited state, 0103 physical sciences, Nuclear fusion, AGATA, Nuclear Experiment (nucl-ex), Connection (algebraic framework), Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range in products of low-energy heavy-ion binary reactions, with complex velocity distributions. The method is based on a detailed study of Doppler-broadened $$\gamma $$ γ -ray lineshapes. Its relevance is demonstrated in connection with the $$^{18}\text {O}(7.0\, \text {MeV/u})+\,^{181}\text {Ta}$$ 18 O ( 7.0 MeV/u ) + 181 Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in $$^{17}\text {O}$$ 17 O and $$^{19}\text {O}$$ 19 O , with known lifetimes, are used to validate the method over the $$\sim 20{-}400\,\text {fs}$$ ∼ 20 - 400 fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by $$\gamma $$ γ -tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.

Published
2021

6. Probing isospin mixing with the giant dipole resonance in the Zn-60 compound nucleus

Author

S. Pascu, J. Kaur, G. Gosta, M. Rocchini, A. Montaner, G. de Angelis, A. Nannini, R. Menegazzo, F. Galtarossa, S. Capra, D. Mengoni, G. Pasqualato, M. Ciemala, C. Porzio, F. Camera, S. M. Lenzi, A. Boso, D. Filipescu, V. Zamfir, J. Yang, A. Giaz, A. Gadea, S. Riboldi, A. Gottardo, S. Brambilla, Tuncay Bayram, B. Wasilewska, A. Maj, D. Brugnara, D. Bazzacco, F. C. L. Crespi, S. Ceruti, J. J. Valiente-Dobón, N. Blasi, M. Siciliano, T. Marchi, N. Marginean, P. R. John, M. Kmiecik, D. R. Napoli, R. Raabe, G. Jaworski, A. Bracco, O. Wieland, G. Benzoni, S. Leoni, A. Mentana, F. Recchia, I. Zanon, B. Million, A. Goasduff, Dmitry Testov, N. Marchini, S. Ziliani, M. Zieblinski, O. Poleshchuk, A. Gozzelino, T. Glodariu, and D. Ghita

Subjects
Physics, Science & Technology, 010308 nuclear & particles physics, SYMMETRY, WIDTH, Resonance, 01 natural sciences, 3. Good health, Dipole, medicine.anatomical_structure, Physics, Nuclear, Isospin, 0103 physical sciences, Physical Sciences, medicine, Atomic physics, 010306 general physics, Nucleus, Mixing (physics), BREAKING
Abstract

ispartof: PHYSICAL REVIEW C vol:103 issue:4 status: published

Published
2021

7. Enhanced alpha-particle production from fusion evaporation reactions leading to Ti-46

Author

F. Gramegna, S. Leoni, Giovanni Casini, Giuseppe Verde, Lorenzo Domenichetti, J. Mabiala, Silvia Piantelli, Luca Morelli, Giuseppe Andreetta, Tommaso Marchi, M. Bruno, Gabriele Pasquali, M. D'Agostino, Sandro Barlini, Daniele Dell’Aquila, Nicla Gelli, L. Scomparin, C. Frosin, Antonio Caciolli, V. L. Kravchuk, P. Ottanelli, Maurizio Bini, G. Mantovani, A. Camaiani, G. Collazuol, G. Pastore, Alessandro Olmi, D. Mengoni, R. Bolzonella, B. Fornal, Ivano Lombardo, A. Buccola, Diego Gruyer, Magda Cicerchia, M. Degerlier, N. Cieplicka-Oryńczak, Daniela Fabris, M. Cinausero, Maria Vittoria Managlia, Simone Valdré, 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), 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), Cicerchia, M., Gramegna, F., Fabris, D., Cinausero, M., Marchi, T., Andreetta, G., Barlini, S., Bini, M., Bolzonella, R., Bruno, M., Buccola, A., Caciolli, A., Camaiani, A., Casini, G., Cieplicka-Orynczak, N., Collazuol, G., D'Agostino, M., Degerlier, M., Dell'Aquila, D., Domenichetti, L., Fornal, B., Frosin, C., Gelli, N., Gruyer, D., Kravchuk, V. L., Leoni, S., Lombardo, I., Mabiala, J., Managlia, M. V., Mantovani, G., Mengoni, D., Morelli, L., Olmi, A., Ottanelli, P., Pasquali, G., Pastore, G., Piantelli, S., Scomparin, L., Valdre, S., and Verde, G.

Subjects
Nuclear reaction, Nuclear and High Energy Physics, Evaporation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, nuclear reaction, Physics, Particles & Fields, Fusion-evaporation, 0103 physical sciences, Charged particles identification, α-emission, 010306 general physics, Physics, Fusion, Science & Technology, 010308 nuclear & particles physics, alpha-emission, charged particles identification, fusion-evaporation, Physics, Nuclear, Chemical engineering, Physical Sciences, α particles
Abstract

In this paper, we report a detailed study on the de-excitation of the 46Ti compound nucleus populated by means of four different reactions: 16O + 30Si at 7 and 8 AMeV, 18O + 28Si at 7 AMeV and 19F + 27Al at 7 AMeV. The GARFIELD detection array was used to measure the light charged particles and the heavy fragments emitted. This setup covers a large fraction of the solid angle with high-granularity. Complete events are chosen through total charge (Z TOT = 22) detection. Fusion-evaporation events are selected based on the condition that only one heavy fragment is detected in coincidence with the light charged particles. The analysis of global observables, such as charge distribution and light charged particle multiplicities, is compatible with the formation of a thermalized compound nucleus for all the four reactions. Nevertheless, an enhanced emission of α-particles with respect to a pure statistical picture is observed at very forward angles (α-particles.

Published
2021

8. Angular momentum generation in nuclear fission

Author

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

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

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

Published
2021

9. Low-spin particle-core and hole-core excitations in Ca41,47,49 isotopes studied by cold-neutron-capture reactions

Author

S. Bottoni, N. Cieplicka-Oryńczak, S. Leoni, B. Fornal, G. Colò, P. F. Bortignon, G. Bocchi, D. Bazzacco, G. Benzoni, A. Blanc, A. Bracco, S. Ceruti, F. C. L. Crespi, G. de France, E. R. Gamba, Ł. W. Iskra, M. Jentschel, U. Köster, C. Michelagnoli, B. Million, D. Mengoni, P. Mutti, Y. Niu, C. Porzio, G. Simpson, T. Soldner, B. Szpak, A. Türler, C. A. Ur, and W. Urban

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Phonon, Astrophysics::High Energy Astrophysical Phenomena, Large array, 01 natural sciences, Neutron capture, symbols.namesake, 0103 physical sciences, symbols, Atomic physics, 010306 general physics, Hpge detector, Hamiltonian (quantum mechanics)
Abstract

We present recent results on the structure of the one-valence-particle $^{41}$Ca and $^{49}$Ca, and one-valence-hole $^{47}$Ca, nuclei. The isotopes of interest were populated via the cold-neutron capture reactions $^{40}$Ca(n,$\gamma$), $^{48}$Ca(n,$\gamma$) and $^{46}$Ca(n,$\gamma$), respectively. The experiments were performed at the Institut Laue-Langevin, within the EXILL campaign, which employed a large array of HPGe detectors. The $\gamma$ decay and level schemes of these nuclei were investigated by $\gamma$-ray coincidence relationships, leading to the identification of 41, 10, and 6 new transitions in $^{41}$Ca, $^{47}$Ca, and $^{49}$Ca, respectively. Branching ratios and intensities were extracted for the $\gamma$ decay from each state, and $\gamma$-ray angular correlations were performed to establish a number of transition multipolarities and mixing ratios, thus helping in the spin assignment of the states. The experimental findings are discussed along with microscopic, self-consistent beyond-mean-field calculations performed with the Hybrid Configuration Mixing model, based on a Skyrme SkX Hamiltonian. The latter suggests that a fraction of the low-spin states of the $^{41}$Ca, $^{49}$Ca, and $^{47}$Ca nuclei is characterized by the coexistence of either 2p-1h and 1p-2h excitations, or couplings between single-particle/hole degrees of freedom and collective vibrations (phonons) of the doubly-magic "core".

Published
2021

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

Author

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

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

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

Published
2021

11. Manifestation of the Berry phase in the atomic nucleus 213Pb

Author

S. Klupp, A. Algora, Roberto Menegazzo, D. Mengoni, F. Naqvi, J. J. Valiente-Dobón, S. Pietri, T. Habermann, J. Benlliure, Branislav Sitar, Alison Bruce, A. Bracco, P. Van Isacker, N. Kurz, Andrea Corsi, E. Sahin, Dirk Rudolph, Imrich Szarka, Helmut Weick, Zs. Podolyák, J. Gerl, J. Grebosz, Davinder Siwal, S. K. Mandal, S. Leoni, T. Engert, D. Bazzacco, A. Prochazka, M. Górska, F. Recchia, S. Lunardi, D. R. Napoli, Hans Geissel, P. Boutachkov, A. Gottardo, F. Camera, Enrique Casarejos, I. Kojouharov, P. H. Regan, E. Gregor, Oliver Wieland, H. J. Wollersheim, A. Sharma, G. de Angelis, C. Nociforo, F. C. L. Crespi, A. Goasduff, C. Domingo-Pardo, A. I. Morales, M. Pfützner, B. Million, G. Benzoni, M. L. Cortés, Philip M Walker, C. A. Ur, Peter Strmen, H. Schaffner, A. Gadea, Maria Doncel, N. Goel, S. M. Lenzi, 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), 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
Nuclear and High Energy Physics, Angular momentum, nucl-th, Nuclear Theory, isomeric decays, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 01 natural sciences, Nuclear Theory (nucl-th), 0103 physical sciences, Subatomic Physics, Nuclear Physics - Experiment, ddc:530, 22 Física, Nuclear Experiment (nucl-ex), 010306 general physics, Spectroscopy, Nuclear Experiment, Physics, Isotope, 010308 nuclear & particles physics, 2207 Física Atómica y Nuclear, Quantum number, lcsh:QC1-999, relativistic projectile fragmentation, ddc, Geometric phase, gamma-ray spectroscopy, Nuclear Physics - Theory, Atomic nucleus, Atomic number, Atomic physics, Nucleon, lcsh:Physics
Abstract

Physics letters / B 816, 136183 (2021). doi:10.1016/j.physletb.2021.136183, Published by North-Holland Publ., Amsterdam

Published
2021

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

Author

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

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

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

Published
2020

13. Detailed low-spin spectroscopy of 65Ni via neutron capture reaction

Author

F. Kandzia, S. Bottoni, C. Costache, Michele Sferrazza, A. Turturica, Takaharu Otsuka, Ulli Köster, Y.H. Kim, N. Cieplicka-Oryńczak, Ł. W. Iskra, C. Michelagnoli, B. Fornal, C. Porzio, S. Leoni, F. C. L. Crespi, Michael Jentschel, N. Marginean, C. Mihai, Yusuke Tsunoda, Paolo Mutti, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Spins, 010308 nuclear & particles physics, Monte Carlo method, FOS: Physical sciences, Généralités, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, Neutron capture, Angular correlation, Excited state, 0103 physical sciences, Oblate spheroid, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Spin (physics), Spectroscopy, Nuclear Experiment
Abstract

An extended investigation of the low-spin structure of the Ni65 nucleus was performed at the Institut Laue-Langevin, Grenoble, France, via the neutron capture reaction Ni64(n,γ)Ni65, using the Fission Product Prompt Gamma-Ray Spectrometer High-Purity Ge array. The level scheme of Ni65 was significantly expanded, with two new levels and 87 newly found transitions. Angular correlation analyses were also performed, allowing us to assign spins and parities for a number of states and to determine multipolarity mixing ratios for selected γ transitions. The low-energy part of the experimental level scheme (up to about 1.4 MeV) was compared with Monte Carlo shell-model calculations, which predict spherical shapes for all states, apart from the 9/2+ and the second excited 1/2- states of oblate deformation., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2020

14. γ spectroscopy of the Y96 isotope: Searching for the onset of shape coexistence before N=60

Author

Ulli Köster, Y.H. Kim, C. Porzio, J. Dudouet, A. Turturica, Cosmin Teodor Mihai, S. Bottoni, N. Marginean, N. Cieplicka-Oryńczak, D. Reygadas, E. Ruiz-Martinez, R. Lica, Michael Jentschel, S. Pascu, B. Fornal, C. Michelagnoli, Ł. W. Iskra, S. Leoni, R. E. Mihai, M. Barani, R. Mărginean, C. Costache, G. Colombi, F. C. L. Crespi, C. R. Nita, and F. Kandzia

Subjects
Physics, Nuclear fission product, Isotope, Spin states, 010308 nuclear & particles physics, Fission, 01 natural sciences, Spectral line, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Spectroscopy
Abstract

Medium and high spin states of the Y96 nucleus, located in the shape-coexistence region near Z=40 and N=60, were populated in thermal-neutron-induced fission of U233 and U235 targets, diluted in a scintillator. γ rays were measured with the FIssion Product Prompt γ-ray Spectrometer (FIPPS) high-purity germanium (HPGe) detector array, using double and triple γ-ray coincidence techniques and taking advantage of the efficient fission tag provided by the scintillating target material. A complex level scheme, extending up to 5.2 MeV and including excitations above the 8+β-decaying isomer, was investigated, and firm spin and parity assignments were given to a number of states, on the basis of angular correlation analysis and considerations on the γ-decay patterns. While the structures built on the 0− ground state and the 8+ isomer show irregular patterns typical for spherical shapes, the (6+) isomeric state at 1655 keV [with half-life of 181(9) ns], and the rotational band built on it [with spin-parity values between (6+) and (9+)], can be explained by Hartree-Fock-Bogoliubov calculations, if an oblate deformation is assumed. This is the first observation of a deformed structure in an N=57 isotone, lying three neutrons away from the N=60 line. An important finding is also the 115-keV transition which connects the (6+) 181(9)-ns isomer to the β-decaying 8+ spherical isomer, allowing us to firmly place the latter at 1541 keV excitation energy. This may be relevant for calculations of electron and antineutrino spectra from fission of actinides, for which Y96 is a prominent product.

Published
2020

15. Lifetime measurements in the odd−A nucleus Hf177

Author

G. Häfner, W. Korten, L. M. Fraile, N. Saed-Samii, A. Esmaylzadeh, Gheorghe Pascovici, Paolo Mutti, J. F. Smith, Zs. Podolyák, W. Urban, Torsten Soldner, Aurelien Blanc, G. S. Simpson, N. Warr, V. Paziy, Ulli Köster, V. Karayonchev, Michael Jentschel, C. A. Ur, C. Townsley, S. Ilieva, Henryk Mach, J. Jolie, A. Vancraeyenest, N. Mǎrginean, L. Knafla, G. Thiamova, Alison Bruce, S. Leoni, J.-M. Régis, S. Lalkovski, P. H. Regan, Petr Alexa, Oliver J. Roberts, and T. Kröll

Subjects
Physics, medicine.anatomical_structure, Spectrometer, 010308 nuclear & particles physics, 0103 physical sciences, Rare earth, Nuclear structure, medicine, Atomic physics, Nanosecond, 010306 general physics, 01 natural sciences, Nucleus
Abstract

Lifetimes of low- and high-spin states in the odd-A nucleus Hf-177 were measured during the EXILL&FATIMA campaign using a spectrometer equipped with eight HPGe-Clover detectors and 16 fast-timing LaBr3(Ce) detectors. For the determination of lifetimes in the pico- to nanosecond regime, the well-established generalized centroid difference method was used. Lifetimes of the 9/2(-), 9/2(+), 11/2(-), 11/2(+) states were remeasured, the lifetimes of the 13/2(-), 17/2(-), 13/2(+), 15/2(+), and 17/2(+) states were determined for the first time and an upper limit for the 19/2(+) state has been established. From these lifetimes absolute reduced transition probabilities were extracted and compared to particle-rotor-model calculations and quasiparticle-phonon-model calculations showing the importance of including multipole-multipole interactions in the description of odd-A nuclei in the rare earth region.

Published
2020

16. Shape-coexistence studies in the Ni isotopic chain by using the selectivity of different reaction mechanisms

Author

B. Fornal, Michele Sferrazza, Yusuke Tsunoda, J. Wilson, C. Michelagnoli, N. Marginean, S. Leoni, Takaharu Otsuka, Institut Laue-Langevin (ILL), ILL, Institut de Physique Nucléaire d'Orsay (IPNO), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Physique, Monte Carlo method, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Molecular physics, 0103 physical sciences, Potential energy surface, Deformation (engineering), Spin (physics), Ground state, Spectroscopy, Nuclear Experiment, Excitation, Sciences exactes et naturelles
Abstract

International audience; We report on the investigation of the shape coexistence phenomenon in the Ni isotopic chain, from A = 62 to A = 66, by using γ-ray spectroscopy techniques and different reaction mechanisms, such as sub-Coulomb barrier transfer reactions and thermal-neutron capture. Our aim is to understand, from the microscopic point of view, the appearance of nuclear deformation in Ni isotopes at low excitation energy. A series of experiments was performed at the Tandem Accelerator Laboratory in Bucharest, at ALTO IPN-Orsay and at the ILL reactor in Grenoble. Various mean-field theoretical approaches, as well as recent state-of-the-art Monte Carlo Shell Model (MCSM) calculations, predict in 66Ni a deep secondary prolate minimum in the nuclear potential energy surface at spin zero, resulting in a hindered electromagnetic decay towards the spherical ground state (i.e., with an E2 transition probability less than 1 W.u.). This has been confirmed in the first experiment performed in Bucharest. Less pronounced prolate minima, at higher excitation energies, are also expected in lighter neutron-rich Ni isotopes, from state-of-the-art Monte Carlo Shell Model (MCSM) calculations. Preliminary results are discussed for 62Ni and 64Ni, in comparison with theory predictions.

Published
2020

17. 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

18. 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

19. 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

20. GRIDSA: femtosecond lifetime measurements with germanium detector arrays

Author

C. Michelagnoli, Michael Jentschel, Y.H. Kim, F. C. L. Crespi, N. Cieplicka-Oryńczak, F. Kandzia, S. Ziliani, S. Leoni, Ulli Köster, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, List mode, Measure (mathematics), Semiconductor detector, symbols.namesake, Recoil, 0103 physical sciences, Femtosecond, symbols, Nuclear fusion, Atomic physics, 010306 general physics, Doppler effect
Abstract

International audience; We demonstrate the possibility to extract nuclear state femtosecond lifetimes from two-step $\gamma $ ray cascades measured with a Ge-detector array. The technique is based on measuring the Doppler shift of a $\gamma $ ray, caused by the recoil of a preceding $\gamma $ ray emission. Since the two $\gamma $ rays are populating/de-populating the same state they form a start/stop signal, the delay of which is compared to the slowing down motion of the nucleus within the target material. A multi-detector array combined with digital acquisition electronics in list mode, allows to measure several angular combinations and two-step cascades efficiently and simultaneously within one single experiment. The concept was demonstrated with the FIPPS array for the $^{35}\hbox {Cl(n,}\gamma \hbox {)}^{36}\hbox {Cl}$ reaction, where we obtained good agreement with literature values showing the validity of the method.

Published
2020

21. g factor of the $12^+$K-isomer in $^{174}$W

Author

F. Camera, A. I. Morales, E. Vigezzi, O. Wieland, C. Michelagnoli, R. Menegazzo, P. Sona, J. J. Valiente-Dobón, D. Bazzacco, A. Nannini, S. Bottoni, Georgi P. Georgiev, D. R. Napoli, S. Ceruti, G. Bocchi, N. Blasi, Luna Pellegri, V. Modamio, C. A. Ur, M. Rocchini, S. Leoni, B. Million, R. Avigo, A. Perego, B. Melon, D. Mengoni, A. Bracco, G. Benzoni, Agnese Giaz, A. Gottardo, F. C. L. Crespi, M. Ottanelli, E. R. Gamba, P. R. John, S. Capra, 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), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Laue-Langevin (ILL), ILL, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, g factor, Landé g-factor, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Tunnel effect, 0103 physical sciences, Quadrupole, Nuclear fusion, Atomic physics, 010306 general physics, Ground state, Dimensionless quantity
Abstract

The g factor of the $$12^+$$ K-isomer in $$^{174}$$ W has been measured by means of the time-differential perturbed angular distribution technique as $$g(12^+)=+0.304(11)$$ . In addition, the half-life of the isomer has been remeasured as $$T_{1/2}(12^+)=124(8)$$ ns, in agreement with the literature value and confirming the anomalous hindrance F of the E2 transition to the $$10^+$$ level of the ground state band with respect to the $$\gamma $$ -tunnelling model prediction. The measured g factor has been compared with estimates based on experimental g factors from odd-mass isotopes in the same mass region and with Nilsson model calculations. The results establish unique features of the $$12^+$$ K-isomer in $$^{174}$$ W, which can possess a non-pure intrinsic configuration and/or can be characterised by values of the intrinsic quadrupole moment $$Q_0$$ and the rotational g factor $$g_R$$ significantly different with respect to the majority of K-isomers at mass $$A \approx 180$$ .

Published
2020

22. Low-lying electric dipole gamma-continuum for the unstable Fe-62,64 nuclei : Strength evolution with neutron number

Author

Eric Clément, B. Birkenbach, A. I. Morales, D. Bazzacco, H. J. Wollersheim, J. J. Valiente-Dobón, D. M. Cullen, L. J. Harkness-Brennan, M. Kmiecik, Alberto Pullia, C. Domingo-Pardo, Luis Sarmiento, C. Nociforo, N. Goel, B. Bruyneel, G. Rainovski, M.D. Salsac, S. Pietri, Begoña Quintana, J. Simpson, Pavel Golubev, T. Habermann, Johan Nyberg, R. Menegazzo, S. Leoni, M. Reese, V. Yu. Ponomarev, A. Maj, T. Arici, A. Gottardo, N. Kurz, M. Górska, S. Brambilla, I. Kojouharov, E. Merchan, M. L. Cortés, Stefano Riboldi, Enrique Sanchis, N. Lalović, Vicente González, R. Avigo, Norbert Pietralla, P. Reiter, F. Camera, M. Labiche, Zs. Podolyák, J. Gerl, D. Ralet, F. Ameil, Andreas Görgen, A. Gadea, A. Bracco, A. Jungclaus, G. Benzoni, O. Stezowski, Dirk Rudolph, D. Curien, J. Eberth, H. C. Boston, S. Bottoni, W. Korten, F. C. L. Crespi, N. Blasi, H. Schaffner, D. Mengoni, M. Lettmann, G. Duchêne, Diego Barrientos, P. H. Regan, F. Didierjean, M. Ciemala, P. Bednarczyk, G. Guastalla, B. Million, E. Gregor, Oliver Wieland, F. Recchia, D. R. Napoli, A. Atac, 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), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Istituto Nazionale di Fisica Nucleare, Science and Technology Facilities Council (UK), Swedish Research Council, Federal Ministry of Education and Research (Germany), European Commission, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Phonon, Astrophysics::High Energy Astrophysical Phenomena, Binding energy, Nuclear Theory, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 64Fe, Dipole excitation around neutron threshold, 62Fe, Subatomär fysik, 0103 physical sciences, Subatomic Physics, ddc:530, Neutron, Nuclear Physics - Experiment, Nuclear structure, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, 62 Fe, Fe, 64, 64 Fe, lcsh:QC1-999, Dipole, Fe-64, Neutron number, Fe-62, AGATA, Atomic physics, lcsh:Physics
Abstract

6 pags., 4 figs., The γ-ray emission from the nuclei Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1 states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy., This work was partially supported by INFN (Italy) and STFC (UK), the Swedish Research Council (Vetenskapsrådet, VR 2010-147, 2011-5253, and 2016-3969), BMBF NuSTAR-AGATA 05P18RDFN9 and BMBF NuSTAR 05P18RDFN1. The project was co-funded by the European Commission under the 7th Framework Program for RTD (2007-2013) under the Capacities Program (Contract Number 262010, ENSAR). This work was par-tially supported by the Ministry of Science, and Generalitat Valenciana, Spain, under the Grants SEV-2014-0398, FPA2017-84756-C4, PROMETEO/2019/005 and by the EU FEDER funds.

Published
2020

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

Author

R. M. Perez-Vidal, T. Marchi, P. Reiter, Georgi P. Georgiev, Andrés P. Zuker, C. Fransen, D. Mengoni, J. Dudouet, Bo Cederwall, C. Theisen, C. Domingo-Pardo, Thomas Braunroth, A. Goasduff, O. Stezowski, W. Korten, F. C. L. Crespi, A. J. Boston, Johan Nyberg, C. Michelagnoli, B. Birkenbach, Vicente González, C. Müller-Gatermann, Tea Mijatović, D. Bazzacco, Hui Li, Enrique Sanchis, D. S. Judson, N. Cieplicka-Oryńczak, B. Million, Diego Barrientos, S. Leoni, M. Labiche, L. J. Harkness-Brennan, A. Jungclaus, F. Recchia, D. Testov, F.J. Egea-Canet, Herbert Hess, J. Eberth, H. C. Boston, A. Lefevre, J. Collado, István Kuti, A. Lemasson, Dóra Sohler, Alberto Pullia, M. D. Salsac, M. Siciliano, A. Gadea, D. R. Napoli, G. Jaworski, A. Lopez-Martens, S. Szilner, G. Benzoni, Maria Doncel, Eric Clément, M. Palacz, P. R. John, M. Zielińska, P. Désesquelles, B. Sayği, Ulrika Jakobsson, J. J. Valiente-Dobón, A. Maj, R. Menegazzo, S. Erturk, F. Nowacki, D. M. Cullen, A. Goldkuhle, 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), Université de Strasbourg (UNISTRA)-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), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, 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), 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), Ege Üniversitesi, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, Université de Strasbourg (UNISTRA)-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), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear and High Energy Physics, Light Sn, chemistry.chemical_element, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 01 natural sciences, Subatomär fysik, Lifetime, Multi-nucleon transfer, Nuclear structure, Tracking array, 0103 physical sciences, Subatomic Physics, Neutron, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, lcsh:QC1-999, chemistry, Pairing, Excited state, Quadrupole, AGATA, Atomic physics, Tin, lcsh:Physics
Abstract

The lifetimes of the low-lying excited states 2(+) and 4(+) have been directly measured in the neutron-deficient Sn-106,Sn-108 isotopes. the nuclei were populated via a deep-inelastic reaction and the lifetime measurement was performed employing a differential plunger device. the emitted gamma 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; 2(1)(+) -> 0(g.s)(+)) values and it describes well the experimental pattern for Sn104-114 ; the B(E2;(+)(4) -> 2(1)(+)) values, measured here for the first time, depend critically on a delicate pairing-quadrupole balance, disclosed by the very precise results in Sn-108. (C) 2020 the Authors. Published by Elsevier B.V., European Union's Seventh Framework Programme for Research and Technological DevelopmentEuropean Union (EU) [262010]; Fondazione Cassa di Risparmio Padova e Rovigo under the project CONPHYT, starting grant in 2017; Swedish Research CouncilSwedish Research Council [822-2005-3332, 821-2010-6024, 821-2013-2304, 621-20145558, 2017-0065]; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2005.0184]; Scientific and Technological Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114F473]; Ministerio de Ciencia e InnovacionInstituto de Salud Carlos IIISpanish Government [SEV-2014-0398, FPA2017-84756-C4, EEBBI-15-09671]; Generalitat ValencianaGeneralitat Valenciana [PROMETEO/2019/005]; EU-FEDER fundsEuropean Union (EU); Croatian Science Foundation [7194]; Hungarian National Research and Innovation Office (NKFIH) [K128947, PD124717, GINOP-2.3.3-15-2016-00034]; Polish National Science Centre under the COPIN-IN2P3 project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569]; Polish National Science Centre under the COPIGAL project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569]; Polish National Science Centre under the POLITA project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569], The authors would like to thank the AGATA and VAMOS collaborations. Special thanks go to the GANIL technical staff for their help in setting up the apparatuses and the good quality beam and to A. Poves for his fruitful comments. This work was partially supported by the European Union's Seventh Framework Programme for Research and Technological Development (grant no. 262010). A.G. acknowledges the support of the Fondazione Cassa di Risparmio Padova e Rovigo under the project CONPHYT, starting grant in 2017. the work was also supported (B.C, H.L., J.N. and U.J.) by Swedish Research Council under the grant agreements nos. 822-2005-3332, 821-2010-6024, 821-2013-2304, 621-20145558 and 2017-0065, and by the Knut and Alice Wallenberg Foundation grant no. 2005.0184, (B.S.) by the Scientific and Technological Council of Turkey (TUBITAK) under the project no. 114F473, (A.G., A.J. and R.P.) by the Ministerio de Ciencia e Innovacion under the contracts nos. SEV-2014-0398, FPA2017-84756-C4 and EEBBI-15-09671, by the Generalitat Valenciana under the grant agreement no. PROMETEO/2019/005 and by the EU-FEDER funds, (T.M and S.S.) by the Croatian Science Foundation under the project no. 7194, (I.K and D.S.) by the Hungarian National Research and Innovation Office (NKFIH) under the project nos. K128947, PD124717 and GINOP-2.3.3-15-2016-00034, (M.P.) by the Polish National Science Centre with the grants nos. 2014-14-M-ST2-00738, 2016-22M-ST2-00269 and 2017-25-B-ST2-01569 under the COPIN-IN2P3, COPIGAL and POLITA projects.

Published
2020

24. Particle-phonon coupling: Understanding the variety of excitations in the low-lying spectra of odd nuclei

Author

S. Leoni, Gianluca Colò, B. Fornal, and A. Bracco

Subjects
Physics, Coupling, Nuclear physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Phonon, 0103 physical sciences, Atomic nucleus, Hadron, Nuclear fusion, 010306 general physics, 01 natural sciences, Spectral line
Abstract

The couplings between particles and vibrations in atomic nuclei play a key role in the understanding of various nuclear properties, as it has been highlighted along several decades. In this contribution, after a short survey of the early discoveries of particle-phonon multiplets around the 208Pb region, we review recent experiments and theoretical attempts to understand low-energy spectra of odd-nuclei close to magic and semi-magic cores, where particle-phonon coupling phenomena play a significant role. The focus will be on nuclei around 48Ca , 132Sn , 208Pb and neutron-rich Ni isotopes. Special emphasis will be given to experimental techniques based on high-resolution $ \gamma$-spectroscopy and to recent theoretical developments aimed at disentangling particle-phonon coupled states and other more hybrid configurations, using the Hybrid Configuration Mixing model that has been recently proposed by the Milano group.

Published
2019

25. Lifetime measurements of short-lived excited states, and shape changes in As69 and Ge66 nuclei

Author

S. Brambilla, M. Zieblinski, T. Hüyük, R. Menegazzo, M. Matejska-Minda, F. Recchia, W. Meczynski, S. Leoni, C. Michelagnoli, E. Farnea, B. Fornal, B. Szpak, P. Bednarczyk, E. Sahin, G. Jaworski, W. Y. Liang, A. Maj, C. A. Ur, J. Styczen, G. de Angelis, M. Krzysiek, M. Ciemala, M. Palacz, Furong Xu, Sibel Zehra Aydin, M. Kmiecik, and R. Wadsworth

Subjects
Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, 01 natural sciences
Published
2019

26. 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

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

Author

I. Homm, M. Ciemała, Stephan Oberstedt, K. Rezynkina, P. A. Söderström, B. Fornal, A. Lopez-Martens, M. Bunce, V. Vedia, D. Verney, J. N. Wilson, J. Nemer, B. Wasilewska, A. Algora, M. Babo, R. B. Gerst, L. M. Fraile, Y. Popovitch, R. Chakma, T. Kurtukian-Nieto, Ł. W. Iskra, W. Paulsen, E. Adamska, D. Ralet, G. Häfner, M. Piersa, G. Benzoni, M. Rudigier, A. Fijałkowska, A. Blazhev, S. Leoni, D. Reygadas Tello, K. Hauschild, P. H. Regan, M. S. Yavahchova, J. Wiederhold, V. Guadilla, N. Warr, C. Delafosse, C. Schmitt, R.L. Canavan, V. Sánchez-Tembleque, K. Miernik, R. Lozeva, I. Matea, P. Davies, Muriel Fallot, N. Jovančević, S. Bottoni, M. Lebois, N. Cieplicka-Oryńczak, P. Adsley, C. Henrich, G. Tocabens, K. Belvedere, D. Gjestvang, T. Kröll, L. Cortes, C. Sürder, L. Qi, S. M. Collins, D. Etasse, M. Heine, Fabio Zeiser, A. Boso, F. Ibrahim, J. Benito, A. Korgul, J. Ljungvall, D. Thisse, L. Le-meur, A. Gottardo, P. Koseoglou, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

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

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

Published
2019

28. Isomer spectroscopy in Ba133 and high-spin structure of Ba134

Author

E. Farnea, H. K. Wang, C. Fransen, K. Schomacker, A. Gadea, W. Korten, P. Reiter, N. Saed-Samii, A. Jungclaus, L. Corradi, A. Vogt, Hans-Jurgen E. Hess, L. Kaya, K. O. Zell, Suzana Szilner, O. Stezowski, A. Blazhev, J. Eberth, A. Bracco, G. Pollarolo, V. Karayonchev, E. Teruya, B. Birkenbach, A. Esmaylzadeh, T. Mijatović, M. Droste, A. M. Stefanini, N. Shimizu, B. Bruyneel, E. Fioretto, Nunzio Itaco, A. Giaz, Yutaka Utsuno, A. Gottardo, L. Kornwebel, F. Recchia, Zs. Podolyák, F. Scarlassara, R. Menegazzo, S. Leoni, L. Coraggio, A. Gargano, G. Montagnoli, R. Hirsch, F. C. L. Crespi, K. Arnswald, J. Jolie, D. Bazzacco, L. Lewandowski, D. Mengoni, J.-M. Régis, C. Michelagnoli, K. Yanase, E. Sahin, D. R. Napoli, C. Müller-Gatermann, K. Wolf, B. Siebeck, C. A. Ur, K. Hadynska-Klek, M. Seidlitz, S. Lunardi, D. Montanari, M. Siciliano, B. Szpak, G. de Angelis, Andreas Görgen, P. R. John, J. J. Valiente-Dobón, Naotaka Yoshinaga, and P. A. Söderström

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Yrast, 0103 physical sciences, Tandem accelerator, Atomic physics, Spin structure, 010306 general physics, Spectroscopy, 7. Clean energy, 01 natural sciences
Abstract

The transitional nuclei $^{134}$Ba and $^{133}$Ba are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The Jπ=19/2+ state at 1942 keV in $^{133}$Ba is identified as an isomer with a half-life of 66.6(20)ns corresponding to a B(E1) value of 7.7(4)×10−6e2fm2 for the Jπ=19/2+ to Jπ=19/2− transition. The level scheme of $^{134}$Ba above the Jπ=10+ isomer is extended to approximately 6 MeV. A pronounced backbending is observed at ℏω=0.38 MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the Z=56 isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional $^{134}$Ba.

Published
2019

29. Evidence of octupole-phonons at high spin in 207Pb

Author

B. Quintana Arnés, G. Bocchi, R. Perez, Raymond J. Carroll, W. Korten, Alberto Pullia, M. Labiche, Zs. Podolyák, A. Navin, Enrique Sanchis, F. Saillant, Norbert Pietralla, F. C. L. Crespi, C. M. Shand, E. Dupont, B. Fornal, D. Kocheva, Diego Barrientos, O. Stezowski, P. Reiter, L. Atanasova, M. Ciemala, Herbert Hess, Roberto Menegazzo, D. Mengoni, B. Birkenbach, J. Collado, H.J. Eberth, Bo Cederwall, D. Ralet, B. Million, A. Maj, P. Van Isacker, D. Wilmsen, J. J. Valiente Dobon, J. Dudouet, F. Recchia, P. Bednarczyk, M. Rejmund, Georgi P. Georgiev, Andrew Stuchbery, A. Goasduff, A. Lemasson, Deyan Yordanov, P. R. John, Salsac, R. L. Lozeva, A. Jungclaus, C. Michelagnoli, A. Blazhev, J. Goupil, S. Franchoo, A. Gadea, L. J. Harkness, Johan Nyberg, S. M. Lenzi, D. L. Balabanski, D. M. Cullen, I. Burrows, T. Konstantinopoulos, Emyr Clement, H. C. Boston, O. Wieland, C. Theisen, A. J. Boston, A. Kusoglu, C. Fransen, A. Korichi, S. Leoni, C. Müller-Gatermann, J. Ljungvall, 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), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Plunger device, Phonon, Nuclear Theory, Octupole phonon, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], gamma-Ray tracking, γ -Ray tracking, 01 natural sciences, 7. Clean energy, Recoil, VAMOS++ spectrometer, AGATA spectrometer, Nuclear deformation, γ-Ray tracking, 0103 physical sciences, Physics::Atomic Physics, Nuclear Experiment, 010306 general physics, Spin (physics), Physics, VAMOS plus plus spectrometer, 010308 nuclear & particles physics, lcsh:QC1-999, Atomic physics, lcsh:Physics
Abstract

A lifetime measurement of the 19/2 state in Pb has been performed using the Recoil Distance Doppler-Shift (RDDS) method. The nuclei of interest were produced in multi-nucleon transfer reactions induced by a Pb beam impinging on a Mo enriched target. The beam-like nuclei were detected and identified in terms of their atomic mass number in the VAMOS++ spectrometer while the prompt γ rays were detected by the AGATA tracking array. The measured large reduced transition probability B(E3,19/2→13/2)=40(8) W.u. is the first indication of the octupole phonon at high spin in Pb. An analysis in terms of a particle-octupole-vibration coupling model indicates that the measured B(E3) value in Pb is compatible with the contributions from single-phonon and single particle E3 as well as E3 strength arising from the double-octupole-phonon 6 state, all adding coherently. A crucial aspect of the coupling model, namely the strong mixing between single-hole and the phonon-hole states, is confirmed in a realistic shell-model calculation.

Published
2019

30. New spectroscopic information on Tl211,213 : A changing structure beyond the N=126 shell closure

Author

S. Leoni, Hans Geissel, A. Sharma, Robert Hoischen, A. M. Denis Bacelar, A. Bracco, Enrique Casarejos, N. Goel, Matthew Reed, A. Prochazka, D. Bazzacco, S. M. Lenzi, T.P.D. Swan, Imrich Szarka, N. Al-Dahan, Philip M Walker, T. Habermann, A. Gottardo, J. Benlliure, Andrea Corsi, A. Gadea, S. Klupp, E. Gregor, C. Nociforo, Zs. Dombrádi, Alison Bruce, D. Mengoni, Oliver Wieland, Roberto Vicençotto Ribas, A. I. Morales, M. Bunce, Helmut Weick, A. Y. Deo, F. Nowacki, K. Eppinger, C. Domingo-Pardo, A. Algora, M. L. Cortés, E. Sahin, S. Pietri, M. Bowry, J. Alcántara Núñez, H. Schaffner, F. Naqvi, T. Engert, K. Steiger, R. Janik, F. C. L. Crespi, M. Pfützner, J. Gerl, N. Alkhomashi, Maria Doncel, H. J. Wollersheim, W. Prokopowicz, F. Farinon, B. Million, C. A. Ur, Peter Strmen, Y. Ayyad, Davinder Siwal, S. K. Mandal, Roberto Menegazzo, F. Camera, Enrico Maglione, J. J. Valiente-Dobón, P. Boutachkov, Dirk Rudolph, J. Grebosz, P. R. P. Allegro, S. Lunardi, P. H. Regan, G. de Angelis, G. Benzoni, F. Recchia, D. R. Napoli, G. F. Farrelly, Zs. Podolyák, M. Górska, Branislav Sitar, N. Kurz, and I. Kojouharov

Subjects
Physics, Nuclear physics, Fragmentation (mass spectrometry), chemistry, Isotope, 010308 nuclear & particles physics, 0103 physical sciences, Nuclear structure, chemistry.chemical_element, Gamma spectroscopy, Uranium, 010306 general physics, 01 natural sciences
Abstract

The neutron-rich isotopes 211;213Tl, beyond the N = 126 shell-closure, have been studied for the first time in isomer γ-ray decay, exploiting the fragmentation of a primary uranium beam at the FRS-RISING (FRagment Separator-Rare ISotopes INvestigation at GSI) setup at GSI. The observed isomeric states in 211;213Tl show a deviation from the seniority-like scheme of 209Tl. The possible interpretation of the data is discussed on the basis of energy-level systematics and shell-model calculations.

Published
2019

31. Comparative study of four reactions at onset of pre-equilibrium emission

Author

F. Gramegna, Maurizio Bini, C. Frosin, D. Fabris, M. D'Agostino, Simone Valdré, Giovanni Casini, Nicla Gelli, G. Collazuol, V. L. Kravchuk, P. Ottanelli, Giacomo Poggi, Antonio Caciolli, Ivano Lombardo, A. Camaiani, Tommaso Marchi, M. Cinausero, D. Mengoni, B. Fornal, Diego Gruyer, Magda Cicerchia, Silvia Piantelli, Sandro Barlini, Gabriele Pasquali, G. Mantovani, S. Leoni, Luca Morelli, Alessandro Olmi, Daniele Dell’Aquila, M. Bruno, N. Cieplicka-Oryńczak, M. Degerlier, 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Reaction mechanism, 010308 nuclear & particles physics, QC1-999, Model prediction, Nuclear structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Charged particle, Nuclear physics, Event selection, 0103 physical sciences, Thermal, Decay chain, 010306 general physics, Cluster analysis
Abstract

The study of the emitted particles, comparing pre-equilibrium and thermal components, is a useful tool to examine the nuclear structure of emitters. Possible clustering effects, which may change the expected decay chain probability, could be highlighted on the competition between different reaction mechanisms. The NUCL-EX collaboration (INFN, Italy) has carried out an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei. In this framework, the reactions 16O+30Si, 18O+28Si, 19F+27Al at 7 AMeV and 16O+30Si at 8 AMeV have been carried out using the GARFIELD+RCo array at Legnaro National Laboratories. Some anomalies in the α-particle emission channels have been evidenced in the measurement reported above, showing in an exclusive way the observed effects related to the entrance channels. The experimental results are compared to model prediction, for which the same filtering and complete event selection have been applied.

Published
2019

32. Shape transition in the neutron-rich Y nuclei and its evolution across the isotopic chain

Author

S. Bottoni, C. Porzio, Łukasz W. Iskra, Michael Jentschel, Yung Hee Kim, C. Michelagnoli, Natalia Cieplicka‒ Oryńczak, S. Leoni, Ulli Köster, F. Kandzia, B. Fornal, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Fission, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Semiconductor detector, Nuclear physics, medicine.anatomical_structure, 0103 physical sciences, medicine, Neutron, Gamma spectroscopy, 010306 general physics, Nuclear Experiment, Nucleus, Excitation
Abstract

The evolution of the deformation across the Y isotopic chain, in the vicinity of N = 60 boundary, has been studied using gamma spectroscopy methods. The nuclei of interest have been produced by neutron induced fission of 235U and 241Pu targets, during two experimental campaigns named EXILL and FIPPS at the Institute Laue-Langevin in Grenoble. The emitted gamma rays have been collected by HPGe and LaBr3 detectors providing the identification of the high-spin levels in the 94Y and 96Y isotopes up to 6 MeV excitation energy, as well as information about the half-lives of the in-band states in the 98Y nucleus. The obtained results shed new light on the onset of deformation in the neutron-rich Y isotopes and, in general, in the A ≈ 100 region.

Published
2019

33. Identification of high-spin proton configurations in Ba136 and Ba137

Author

C. Fransen, C. Müller-Gatermann, D. Bazzacco, B. Birkenbach, R. Hetzenegger, C. A. Ur, F. Recchia, R. Hirsch, L. Lewandowski, L. Corradi, Katarzyna Hadynska-Klek, M. Seidlitz, P. R. John, P. Reiter, D. Mengoni, L. Kaya, J. J. Valiente-Dobón, A. Vogt, L. Coraggio, G. Pollarolo, D. Rosiak, W. Korten, E. Sahin, N. Saed-Samii, A. Blazhev, A. Giaz, C. Michelagnoli, A. Jungclaus, E. Farnea, O. Stezowski, A. Gottardo, K. Arnswald, B. Bruyneel, B. Szpak, Nunzio Itaco, Zs. Podolyák, Andreas Görgen, R. Menegazzo, F. Scarlassara, M. Droste, A. M. Stefanini, A. Gargano, J. Jolie, T. Mijatović, M. Weinert, Suzana Szilner, A. Gadea, K. O. Zell, P. A. Söderström, D. R. Napoli, K. Wolf, M. Siciliano, G. Montagnoli, F. C. L. Crespi, S. Lunardi, E. Fioretto, D. Montanari, Hans-Jurgen E. Hess, G. de Angelis, A. Bracco, J. Eberth, and S. Leoni

Subjects
Physics, Proton, Spins, Isotope, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, 7. Clean energy, 0103 physical sciences, AGATA, Atomic physics, 010306 general physics, Spin (physics), Spectroscopy, Excitation
Abstract

The high-spin structures of 136Ba and 137Ba are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. 136Ba is populated in a 136Xe+238U MNT reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and in two 9Be + 130Te fusion-evaporation reactions using the High-efficiency Observatory for -Ray Unique Spectroscopy (HORUS) at the FN tandem accelerator of the University of Cologne, Germany. Furthermore, both isotopes are populated in an elusive reaction channel in the 11B+130Te fusion-evaporation reaction utilizing the HORUS -ray array. The level scheme above the J� = 10+ isomer in 136Ba is revised and extended up to an excitation energy of approx. 5.5 MeV. From the results of angular-correlation measurements, the Ex = 3707- and Ex = 4920-keV states are identified as the bandheads of positive- and negative-parity cascades. While the high-spin regimes of both 132Te and 134Xe are characterized by high-energy 12+ ! 10+ transitions, the 136Ba E2 ground-state band is interrupted by negativeparity states only a few hundred keV above the J� = 10+ isomer. Furthermore, spins are established for several hitherto unassigned high-spin states in 137Ba. The new results close a gap along the highspin structure of N < 82 Ba isotopes. Experimental results are compared to large-scale shell-model calculations employing the GCN50:82, Realistic SM, PQM130 and SN100PN interactions. The calculations suggest that the bandheads of the positive-parity bands in both isotopes are predominantly of proton character.

Published
2019

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

Author

S. Bottoni, M. Lebois, L. Qi, D. Reygadas Tello, R. Shearman, I. Homm, R. B. Gerst, J. N. Wilson, T. Kröll, D. Verney, A. Boso, A. Oberstedt, I. Matea, P. Koseoglou, P. A. Söderström, M. Babo, G. Häfner, M. Piersa, D. Thisse, B. Fornal, M. Rudigier, V. Sanchez, J. Wiederhold, C. Henrich, P. H. Regan, A. Lopez-Martens, F. Ibrahim, K. Miernik, J. Ljungvall, N. Cieplicka-Oryńczak, M. Diakaki, P. Inavov, A. Algora, C. Delafosse, N. Warr, G. Tocabens, J. Benito Garcia, K. Belvedere, S. Leoni, Y. Popovitch, Muriel Fallot, J. Nemer, K. Rezynkina, W. Paulson, C. Sürder, M. Bunce, D. Gestvang, D. Knezevic, V. Guadilla-Gomez, K. Hauschild, Zs. Podolyák, L. Cortes, D. Ralet, A. Gottardo, A. Dragic, E. Adamska, G. Benzoni, R. Lozeva, R. Chakma, N. Jovančević, S. Oberstedt, R. Canavan, F. Adsley, P. Davies, M. Yavachova, C. Schmitt, M. Heine, Fabio Zeiser, D. Etasse, L. M. Fraile, T. Kurtukian-Nieto, A. Blazhev, L. Iskra, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Paris-Saclay, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes - Faculté des Sciences et des Techniques, and Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique)

Subjects
Physics, education.field_of_study, Spectrometer, 010308 nuclear & particles physics, Fission, Astrophysics::High Energy Astrophysical Phenomena, Population, Aucun, General Physics and Astronomy, Shields, chemistry.chemical_element, Germanium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, chemistry, 0103 physical sciences, Neutron source, Neutron, Atomic physics, 010306 general physics, education, Spectroscopy, Nuclear Experiment
Abstract

The ʋ-ball is a high-efficiency hybrid spectrometer which consists of both germanium (Ge) detectors and associated anti-Compton BGO shields, coupled to lanthanum bromide (LaBr3) detectors. The hybrid configuration provides a combination of both excellent energy and timing resolutions. The ʋ-ball geometry allows the coupling with the LICORNE directional neutron source at the ALTO facility of the IPN, Orsay. This opens the possibility to perform precise spectroscopy of neutron induced reactions and was used for two experiments during the recent experimental campaign. These two experiments are described here: 1. Spectroscopy of the neutron-rich fission fragments produced in the 238U(n; f) and 232Th(n; f) reactions; 2. Spectroscopy above the shape isomer in 238U. The 238U(n; f) and 232Th(n; f) reactions produce hundreds of neutron-rich nuclei on which gamma-ray spectroscopy can be performed. The main goal of the experiment aiming to populate the shape isomer in 238U is the measurement of the gamma-ray and fission decay branches as well as determination of level scheme in the super-deformed minimum. The shape isomer is populated by 238U(n; n') reaction, which gives a very advantageous population cross section over other reactions. More detailed descriptions of these two ʋ-ball experiments will be presented here.

Published
2019

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

Author

S. Ziliani, M. Ciemała, F. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, O. Dorvaux, S. Erturk, G. De France, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, B. Million, C. Müller-Gatermann, P. Napiorkowski, V. Nanal, M. Matejska-Minda, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, B. Wasilewska, M. Ziębliński, Fornal, Bogdan -- 0000-0002-1142-8067, Ciemala, Michal -- 0000-0001-5328-720X, [Ziliani, S. -- Crespi, F. -- Leoni, S. -- Bracco, A. -- Bottoni, S. -- Camera, F.] Univ Milan, Milan, Italy -- [Ziliani, S. -- Crespi, F. -- Leoni, S. -- Benzoni, G. -- Bracco, A. -- Boiano, C. -- Bottoni, S. -- Brambilla, S. -- Camera, F. -- Million, B.] INFN, Sez Milano, Milan, Italy -- [Ciemala, M. -- Fornal, B. -- Maj, A. -- Bednarczyk, P. -- Cieplicka-Orynczak, N. -- Grebosz, J. -- Iskra, L. W. -- Kmiecik, M. -- Mazurek, K. -- Wasilewska, B.] Polish Acad Sci, Inst Nucl Phys, Krakow, Poland -- [Bast, M. -- Beckers, M. -- Braunroth, T. -- Goldkuhle, A. -- Mueller-Gatermann, C.] IKP Cologne, Cologne, Germany -- [Clement, E. -- De France, G. -- Jacquot, B. -- Kim, Y. -- Lemasson, A. -- Li, H. -- Rejmund, M.] CEA, DSAM, GANIL, Caen, France -- [Clement, E. -- De France, G. -- Jacquot, B. -- Kim, Y. -- Lemasson, A. -- Li, H. -- Rejmund, M.] CNRS, IN2P3, Caen, France -- [Dorvaux, O. -- Schmitt, Ch] CNRS, IN2P3, IPHC UMR 7178, Strasbourg, France -- [Erturk, S.] Nigde Univ, Nigde, Turkey -- [Harakeh, M. N.] KVI Ctr Adv Radiat Technol, Groningen, Netherlands -- [Kicinska-Habior, M. -- Matea, I -- Stefan, I] Warsaw Univ, Fac Phys, Warsaw, Poland -- [Kicinska-Habior, M. -- Matea, I -- Stefan, I] IPN, Orsay Lab, Orsay, France -- [Michelagnoli, C.] ILL Grenoble, Grenoble, France -- [Napiorkowski, P. -- Matejska-Minda, M.] Univ Warsaw, Heavy Ion Lab, Warsaw, Poland -- [Nanal, V] Dept Nucl & Atom Phys, Mumbai, Maharashtra, India -- [Stanoiu, M.] IFIN HH, Bucharest, Romania -- [Zieblinski, M.] CEA, DRF, IRFU, Ctr CEA Saclay, Saclay, France, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut Laue-Langevin (ILL), ILL, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 0-Belirlenecek, and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, Spectrometer, 010308 nuclear & particles physics, General Physics and Astronomy, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 0-Belirlenecek, Nuclear physics, Nuclear interaction, Ab initio quantum chemistry methods, 0103 physical sciences, Neutron, AGATA, Spectroscopy, Nuclear Experiment
Abstract

Zakopane Conference on Nuclear Physics - Extremes of the Nuclear Landscape -- AUG 26-SEP 02, 2018 -- Zakopane, POLAND, WOS: 000463866500052, Recent ab initio calculations pointed out the importance of the three-body terms of the nuclear interaction, in the description of the structure of n-rich systems. The state lifetimes in light n-rich carbon and oxygen nuclei have been predicted to be sensitive to the three-body terms and, in this context, an experiment, aiming at the measurement of these lifetimes, was performed in GANIL in July 2017 with the AGATA and PARIS arrays coupled to the VAMOS++ magnetic spectrometer. Details on the AGATA preliminary data analysis are presented., National Science Centre, Poland (NCN) [2013/08/M/ST2/00257, 2014/14/M/ST2/00738, 2016/22/M/ST2/00269], This work was supported by the National Science Centre, Poland (NCN) under contracts No. 2013/08/M/ST2/00257, 2014/14/M/ST2/00738 and 2016/22/M/ST2/00269.

Published
2019

36. MariX, an advanced MHz-class repetition rate X-ray source for linear regime time-resolved spectroscopy and photon scattering

Author

Z. Mazzotta, Riccardo Valdagni, M. Moretti Sala, Silvia Morante, Lucio Rossi, Massimo Sorbi, M. Opromolla, Adolfo Esposito, F. Camera, Giorgio Turchetti, Alberto Pullia, Massimo Petrarca, Francesco Ragusa, S. Capra, Andrea Castoldi, Massimiliano Romé, Dario Giannotti, Francesco Stellato, Marcel Ruijter, Luca Serafini, Antonio Sarno, A. Bellandi, Mauro Carrara, A. Loria, Riccardo Calandrino, S. Samsam, Paola Mangili, Chiara Guazzoni, Daniele Sertore, L. Monaco, Verardo Torri, Alberto Bacci, Cristina Vaccarezza, Giacomo Claudio Ghiringhelli, Vittoria Petrillo, Francesco Canella, A. Del Vecchio, M. Bertucci, Marco A. C. Potenza, Alberto Tagliaferri, Alessandro Cianchi, C. Paulin, Giorgio Rossi, Paolo Russo, Tommaso Mazza, Mauro Gambaccini, Ermanno Pinotti, Matteo G. A. Paris, Ezio Puppin, Paolo Laporta, Roberta Ramponi, Giovanni Mettivier, Gianluca Galzerano, Simone Cialdi, P. Cardarelli, Fabian Zomer, Edoardo Suerra, Stefano Olivares, Martino Bolognesi, Daniele Nutarelli, F. Prelz, Chiara Meroni, L. Faillace, F. Broggi, Alke Martens, Bruno Paroli, Nicola Coluccelli, Angelo Vanzulli, Illya Drebot, Gianfranco Paternò, M. Rossetti Conti, Angelo Taibi, M. Statera, Bruno Spataro, Dario Giove, C. Curatolo, Flavia Groppi, S. Leoni, Rocco Paparella, S. Di Mitri, Laura Perini, G.M. Cattaneo, Carlo Fiorini, Kevin Dupraz, Massimo Ferrario, Kevin Cassou, Carlo Pagani, Paolo Piseri, Giovanni Onida, Andrea Rossi, R. Castriconi, Paolo Michelato, Angelo Bosotti, Laboratoire de l'Accélérateur Linéaire (LAL), 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-Saclay, Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS), Serafini, L., Bacci, A., Bellandi, A., Bertucci, M., Bolognesi, M., Bosotti, A., Broggi, F., Calandrino, R., Camera, F., Canella, F., Capra, S., Cardarelli, P., Carrara, M., Cassou, K., Castoldi, A., Castriconi, R., Cattaneo, G. M., Cialdi, S., Cianchi, A., Coluccelli, N., Curatolo, C., Del Vecchio, A., Di Mitri, S., Drebot, I., Dupraz, K., Esposito, A., Faillace, L., Ferrario, M., Fiorini, C., Galzerano, G., Gambaccini, M., Ghiringhelli, G., Giannotti, D., Giove, D., Groppi, F., Guazzoni, C., Laporta, P., Leoni, S., Loria, A., Mangili, P., Martens, A., Mazza, T., Mazzotta, Z., Meroni, C., Mettivier, Giovanni, Michelato, P., Monaco, L., Morante, S., Moretti Sala, M., Nutarelli, D., Olivares, S., Onida, G., Opromolla, M., Pagani, C., Paparella, R., Paris, M. G. A., Paroli, B., Paternò, G., Paulin, C., Perini, L., Petrarca, M., Petrillo, V., Pinotti, E., Piseri, P., Potenza, M. A. C., Prelz, F., Pullia, A., Puppin, E., Ragusa, F., Ramponi, R., Romè, M., Rossetti Conti, M., Rossi, A. R., Rossi, L., Ruijter, M., Russo, Paolo, Samsam, S., Sarno, Antonio, Sertore, D., Sorbi, M., Spataro, B., Statera, M., Stellato, F., Suerra, E., Tagliaferri, A., Taibi, A., Torri, V., Turchetti, G., Vaccarezza, C., Valdagni, R., Vanzulli, A., Zomer, F., Rossi, G., and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear and High Energy Physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, Linear accelerators Free-electron lasers, Linear accelerators, Free-electron lasers, Medicine applications, Socio-culturale, 02 engineering and technology, 01 natural sciences, 7. Clean energy, Instrumentation, law.invention, Optics, law, 0103 physical sciences, 010306 general physics, Spectroscopy, Physics, [PHYS]Physics [physics], Range (particle radiation), business.industry, Scattering, Particle accelerator, Photoelectric effect, 021001 nanoscience & nanotechnology, Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin), Pulse (physics), Time-resolved spectroscopy, 0210 nano-technology, business
Abstract

The need of a fs-scale pulsed, high repetition rate, X-ray source for time-resolved fine analysis of matter (spectroscopy and photon scattering) in the linear response regime is addressed by the conceptual design of a facility called MariX (Multi-disciplinary Advanced Research Infrastructure for the generation and application of X-rays) outperforming current X-ray sources for the declared scope. MariX is based on the original design of a two-pass two-way superconducting linear electron accelerator , equipped with an arc compressor, to be operated in CW mode (1 MHz). MariX provides FEL emission in the range 0.2–8 keV with 1 0 8 photons per pulse ideally suited for photoelectric effect and inelastic X-ray scattering experiments. The accelerator complex includes an early stage that supports an advanced inverse Compton source of very high-flux hard X-rays of energies up to 180 keV that is well adapted for large area radiological imaging, realizing a broad science programme and serving a multidisciplinary user community, covering fundamental science of matter and application to life sciences, including health at preclinical and clinical level.

Published
2019

37. Studying the Decay of $^{46}$Ti*: Does Different Partner Structure Influence the Competing Mechanisms and the Following Compound Nucleus Decay?

Author

V. L. Kravchuk, A. Camaiani, F. Gramegna, Diego Gruyer, Magda Cicerchia, Luca Morelli, Silvia Piantelli, Sandro Barlini, Alessandro Olmi, D. Mengoni, M. Cinausero, C. Frosin, T. Marchi, Gabriele Pasquali, D. Fabris, Nicla Gelli, P. Ottanelli, Maurizio Bini, G. Mantovani, Giovanni Casini, M. Degerlier, G. Collazuol, Daniele Dell’Aquila, N. Cieplicka-Oryńczak, Giacomo Poggi, Antonio Caciolli, Ivano Lombardo, B. Fornal, M. Bruno, S. Leoni, Simone Valdré, M. D'Agostino, 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), 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
medicine.anatomical_structure, 010308 nuclear & particles physics, Chemistry, Chemical physics, 0103 physical sciences, medicine, Structure (category theory), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Nucleus
Abstract

International audience; A useful tool to underline possible structure effects on the competition between different reaction mechanisms, which may change the expected decay chain probability, is the exclusive study of light charged particles emission from hot light composite systems. In particular, the influence of projectile structure may be evidenced by studying the competition between fast and thermal emissions. In this framework, the four reactions ^16O+^30Si, ^18O+^28Si, ^19F+^27Al at 7 MeV/u and ^16O+^30Si at 8 MeV/u have been carried out using the GARFIELD+RCo array at Legnaro National Laboratories. Some anomalies in the α-particle emission channels have been evidenced in the measurements reported above, showing in an exclusive way the observed effects related to the entrance channels. The experimental results are compared to statistical model predictions, for which the same filtering and complete event selection have been applied.

Published
2018

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

Author

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

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

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

Published
2016

39. Population and decay of superdeformed nuclei probed by discrete and quasi-continuum γ-ray spectroscopy

Author

T. Lauritsen, T. L. Khoo, S. Leoni, Sunniva Siem, Thomas Døssing, A. Lopez-Martens, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM SNO), and Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Population, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Superdeformation, 0103 physical sciences, Gamma spectroscopy, Gamma-ray spectroscopy, Statistical theory and fluctuations, Nuclear Experiment, 010306 general physics, education, Spectroscopy, Quantum tunnelling, [PHYS]Physics [physics], Physics, education.field_of_study, 010308 nuclear & particles physics, Gamma ray, Nuclear structure, Chaos in nuclear systems, Atomic physics, Collective levels, Excitation
Abstract

Nuclear superdeformation at high spin was discovered a little over 30 years ago. Since then, a large body of data has been collected on the subject and many new and interesting phenomena have been discovered. In particular, the way superdeformed states are populated and depopulated offers a unique laboratory to study rotational motion as a function of excitation energy and the evolution of nuclear structure over a large interval in energy and spin. This article focuses on the experimental techniques and methods developed to study the quasicontinuous spectra of gamma rays emitted by rapidly rotating superdeformed nuclei and presents the results regarding rotational damping, the transition from ordered to chaotic motion and quantum tunnelling in a complex environment.

Published
2016

40. Contrasting properties of particle-particle and hole-hole excitations in 206Tl and 210Bi nuclei

Author

F. C. L. Crespi, S. Leoni, A. Gargano, Aurelien Blanc, C. Michelagnoli, E. Ruiz-Martinez, Ulli Köster, N. Cieplicka-Oryńczak, S. Bottoni, Ł. W. Iskra, Paolo Mutti, G. Benzoni, Michael Jentschel, V. Werner, B. Fornal, Norbert Pietralla, Institut Laue-Langevin (ILL), and ILL

Subjects
Nuclear and High Energy Physics, Work (thermodynamics), Deduced levels and Jπ 206 Tl, Deduced levels and [formula omitted]206Tl, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Thermal neutron capture, 210Bi, 01 natural sciences, 7. Clean energy, Comparison with shell-model calculations, Nuclear physics, Matrix (mathematics), Atomic orbital, γγ-coin. 206Tl, 0103 physical sciences, Diagonal matrix, medicine, Nuclear structure 206 Tl, 010306 general physics, Mixing (physics), Physics, 010308 nuclear & particles physics, 210 Bi, lcsh:QC1-999, medicine.anatomical_structure, γγ -coin. 206 Tl, Nuclear structure 206Tl, Particle, Branching ratios 206Tl, Nucleus, lcsh:Physics, Branching ratios 206 Tl
Abstract

A complete-spectroscopy investigation of low-lying, low-spin states in the one-proton-hole and one-neutron-hole nucleus 206Tl has been performed by using thermal neutron capture and γ-coincidence technique with the FIPPS Ge array at ILL Grenoble. The new experimental results, together with data for the one-proton-particle and one-neutron-particle nucleus 210Bi (taken from a previous study done at ILL in the EXILL campaign), allowed for an extensive comparison with predictions of shell-model calculations performed with realistic interactions. No phenomenological adjustments were introduced in the calculations. In 210Bi, state energies, transition multipolarities and decay branchings agree well with theory for the three well separated multiplets of states which dominate the low-lying excitations. On the contrary, in 206Tl significant discrepancies are observed: in the same energy region, six multiplets were identified, with a significant mixing among them being predicted, as a consequence of the smaller energy separation between the active orbitals. The discrepancies in 206Tl are attributed to the larger uncertainties in the determination of the off-diagonal matrix elements of the realistic shell-model interaction with respect to the calculated diagonal matrix elements, the only ones playing a major role in the case of 210Bi. The work points to the need of more advanced approaches in the construction of the realistic interactions. Keywords: Nuclear structure 206Tl, 210Bi, γγ-coin. 206Tl, Branching ratios 206Tl, Deduced levels and Jπ 206Tl, Comparison with shell-model calculations

Published
2020

41. Millisecond 23/2+ isomers in the N=79 isotones Xe133 and Ba135

Author

W. Korten, K. O. Zell, A. Vogt, S. Leoni, D. Bazzacco, Nunzio Itaco, F. Recchia, Andreas Görgen, R. Hirsch, Zs. Podolyák, B. Birkenbach, B. Szpak, P. R. John, J. J. Valiente-Dobón, Suzana Szilner, L. Lewandowski, C. Fransen, D. Mengoni, P. A. Söderström, P. Reiter, R. Menegazzo, J. Jolie, G. Pollarolo, E. Fioretto, A. Giaz, E. Farnea, L. Corradi, A. Gottardo, C. A. Ur, L. Kaya, A. Jungclaus, A. Gargano, K. Hadynska-Klek, M. Seidlitz, D. R. Napoli, E. Sahin, K. Wolf, M. Weinert, R. Hetzenegger, J. Eberth, L. Coraggio, S. Lunardi, Hans-Jurgen E. Hess, A. Bracco, C. Müller-Gatermann, D. Montanari, O. Stezowski, G. de Angelis, G. Montagnoli, D. Rosiak, F. C. L. Crespi, M. Siciliano, C. Michelagnoli, M. Droste, A. M. Stefanini, N. Saed-Samii, A. Blazhev, K. Arnswald, B. Bruyneel, F. Scarlassara, T. Mijatović, and A. Gadea

Subjects
Physics, Millisecond, Spectrometer, 010308 nuclear & particles physics, Nuclear structure, Nuclear shell model, Parity (physics), 01 natural sciences, Nuclear physics, 0103 physical sciences, AGATA, 010306 general physics, Spectroscopy, Excitation
Abstract

Detailed information on isomeric states in A ≈ 135 nuclei is exploited to benchmark shell-model calculations in the region northwest of doubly-magic nucleus 132Sn. The N = 79 isotones 133Xe and 135Ba are studied after multinucleon transfer (MNT) in the 136Xe + 208Pb reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and in a pulsed-beam experiment at the FN tandem accelerator of the University of Cologne, Germany utilizing a 9Be+130Te fusion-evaporation reaction at a beam energy of 40 MeV. Isomeric states are identified via delayed γ-ray spectroscopy. Hitherto tentative excitation energy, spin, and parity assignments of the 2107-keV Jπ = 23/2+ isomer in 133Xe are confirmed and a half-life of T1/2 = 8.64(13) ms is measured. The 2388-keV state in 135Ba is identified as a Jπ = 23/2+ isomer with a half-life of 1.06(4) ms. The new results show a smooth onset of isomeric Jπ = 23/2+ states along the N = 79 isotones and close a gap in the high-spin systematics towards the recently investigated Jπ = 23/2+ isomer in 139Nd. The resulting systematics of M2 reduced transition probabilities is discussed within the framework of the nuclear shell model. Latest large-scale shell-model calculations employing the SN100PN, GCN50:82, SN100-KTH, and a realistic effective interaction reproduce the experimental findings generally well and give insight into the structure of the isomers.

Published
2018

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

Author

M. Ciemała, S. Ziliani, F. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, O. Dorvaux, S. Ertürk, G. De France, A. Goldkuhle, J. Grębosz, M.N. Harakeh, Ł.W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, B. Millon, C. Müller-Gatermann, P. Napiorkowski, V. Nanal, M. Matejska-Minda, M. Rejmund, B. Sowicki, Ch. Schmitt, M. Stanoiu, I. Stefan, B. Wasilewska, M. Zielińska, M. Ziębliński, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut Laue-Langevin (ILL), ILL, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Excited state, 0103 physical sciences, AGATA, Neutron, Nuclear Experiment
Abstract

International audience; An experiment aiming at measuring lifetimes of the second 2+ excited states in neutron-rich C and O isotopes was recently performed at the GANIL laboratory, in France. In these nuclei, recent ab initio calculations provide a detailed description of the nuclear excited states, predicting a strong sensitivity of the electromagnetic transition probabilities to the details of the nucleon–nucleon interactions, especially in connection with the role played by the three-body (NNN) forces. Thus, the measurement of 2 + states lifetimes in this region will be a stringent test of the importance of including the NNN forces in describing the electromagnetic properties of selected nuclear states. This contribution reports on the status of the experimental analysis for the case of lifetimes in 20O.

Published
2018

43. High-spin structure in the transitional nucleus Xe131 : Competitive neutron and proton alignment in the vicinity of the N=82 shell closure

Author

Naotaka Yoshinaga, W. Korten, A. Bracco, E. Fioretto, Agnese Giaz, Koji Higashiyama, C. A. Ur, F. Recchia, A. Vogt, S. Lunardi, J. Jolie, B. Birkenbach, R. Hirsch, D. Montanari, A. Jungclaus, G. Montagnoli, Suzana Szilner, K. Arnswald, O. Stezowski, B. Bruyneel, G. de Angelis, P. Reiter, F. C. L. Crespi, P. R. John, S. Leoni, B. Fu, T. Steinbach, B. Szpak, E. Farnea, L. Coraggio, A. Gargano, N. Saed-Samii, A. Blazhev, A. Gadea, Roberto Menegazzo, D. Mengoni, M. Siciliano, D. Bazzacco, E. Teruya, M. Queiser, D. Schneiders, Andreas Görgen, A. Gottardo, Fernando Scarlassara, L. Lewandowski, C. Michelagnoli, J. F. Smith, G. Pollarolo, K. Hadynska-Klek, M. Seidlitz, Tea Mijatović, B. Siebeck, J. J. Valiente-Dobón, J. Eberth, C. Müller-Gatermann, E. Sahin, K. O. Zell, D. R. Napoli, K. Wolf, Alberto Pullia, A. M. Stefanini, R. Hetzenegger, P. A. Söderström, D. Rosiak, Nunzio Itaco, Herbert Hess, Zs. Podolyák, C. Fransen, L. Corradi, and L. Kaya

Subjects
Physics, Spectrometer, Isotope, Proton, 010308 nuclear & particles physics, Shell (structure), Nuclear structure, Spin structure, 01 natural sciences, Nuclear physics, 0103 physical sciences, Neutron, AGATA, 010306 general physics
Abstract

The transitional nucleus 131Xe is investigated after multinucleon transfer (MNT) in the 136Xe+208Pb and 136Xe+238U reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy and as an elusive reaction product in the fusion-evaporation reaction 124Sn(11B,p3n) 131Xe employing the HORUS γ-ray array coupled to a double-sided silicon strip detector (DSSSD) at the University of Cologne, Germany. The level scheme of 131Xe is extended to 5 MeV. A pronounced backbending is observed at ~ω ≈ 0.4 MeV along the negative-parity one-quasiparticle νh11/2(α = −1/2) band. The results are compared to the high-spin systematics of the Z = 54 isotopes and the N = 77 isotones. Large-scale shell-model calculations (LSSM) employing the PQM130, SN100PN, GCN50:82, SN100-KTH and a realistic effective interaction reproduce the experimental findings and provide guidance to elucidate the structure of the high-spin states. Further calculations in 129−132Xe provide insight into the changing nuclear structure along the Xe chain towards the N = 82 shell closure. Proton occupancy in the π 0h11/2 orbital is found to be decisive for the description of the observed backbending phenomenon.

Published
2018

44. Study on the Decay of $^{46}$Ti

Author

M. Cinausero, I. Lombardo, D. Dell’Aquila, N. Cieplicka-Orynczak, D. Mengoni, Maurizio Bini, B. Fornal, Giacomo Poggi, Antonio Caciolli, C. Frosin, P. Ottanelli, Alessandro Olmi, G. Pastore, Sandro Barlini, T. Marchi, Magda Cicerchia, M. Degerlier, Gabriele Pasquali, Luca Morelli, D. Fabris, S. Leoni, Silvia Piantelli, Simone Valdré, A. Camaiani, M. D'Agostino, D. Gruyer, F. Gramegna, G. Collazzuol, G. Mantovani, Giovanni Casini, M. Bruno, Nicla Gelli, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Physics, 010308 nuclear & particles physics, Condensation, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Thermalisation, Chemical physics, 0103 physical sciences, Cluster (physics), 010306 general physics, Nuclear Experiment
Abstract

International audience; The pre-formation of α-clusters in α-conjugate nuclei or their dynamical condensation during nuclear reactions was largely debated, among the methods to probe a possible cluster structure in nuclei, it has been suggested to study pre-equilibrium emitted particles and clusters following their emission during the dynamical part of the reaction, before a full thermalization takes place.

Published
2018

45. 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

46. 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

47. Towards the lowest-energy limit for light ions identification with silicon pixel-type detectors

Author

S. Brambilla, F. C. L. Crespi, B. Fornal, S. Capra, G. Bocchi, C. Boiano, G. Jaworski, N. Cieplicka-Oryńczak, M. Siciliano, M. Ciemala, K. Hadynska-Klek, J. J. Valiente-Dobón, D. Mengoni, D. Bazzacco, Ł. W. Iskra, P. R. John, J.A. Dueñas, G. Benzoni, Alain Goasduff, S. Leoni, F. Recchia, and D. Testov

Subjects
Physics, Nuclear and High Energy Physics, Silicon, 010308 nuclear & particles physics, Detector, chemistry.chemical_element, Alpha particle, Kinetic energy, 01 natural sciences, Particle identification, Ion, Nuclear physics, chemistry, 0103 physical sciences, Nuclear fusion, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

An in-beam test of two pixel-type silicon detectors of the TRACE detector project has been performed at Laboratori Nazionali di Legnaro (Italy). The aim was to investigate the lowest kinetic energy values at which isotopic identification of heavy-ion reactions products with mass $ A\sim 10$ is possible, by using a single-layer silicon detector. Two separate read-out chains, analog and digital, were used, and the Pulse Shape Analysis technique was employed to obtain the particle identification matrices for the digitally processed data. The results confirmed the high capability of the Pulse Shape Analysis method which can be used for light ion identification, with performances similar to the analog approach. Separation in both charge and mass was obtained for Li and Be isotopes, however, the presence of a significant background from alpha particles severely limited the data analysis in the lower energy region. Due to this effect, the identification of the light products (7, 6Li isotopes) could be possible down to $ \sim 24.5$ MeV only, while the 9, 7Be isotopes were separable down to $ \sim 29$ MeV. This gives the value of $ < 4$ MeV/nucleon as the lowest kinetic energy for light products identification by using the pixel-type detectors of the TRACE project, in the present experimental conditions.

Published
2018

48. Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

Author

A. Maj, C. Portail, F. Rotaru, B. Fornal, M. A. Naumenko, L. Olivier, F. de Oliveira Santos, S. Franchoo, A. Chbihi, P. Bednarczyk, A. V. Karpov, C. Petrone, Bertrand Jacquot, Oleg B. Tarasov, Ł. W. Iskra, Yu. E. Penionzhkevich, F. Azaiez, T. Lauritsen, D. Verney, M. Stanoiu, B. Szpak, F. C. L. Crespi, M. Maccormick, O. Sorlin, O. Kamalou, H. Savajols, I. Stefan, R. V. F. Janssens, I. Matea, N. Cieplicka-Oryńczak, M. Ciemala, Dieter Ackermann, Y. Blumenfeld, S. Leoni, Paola Marini, S. Calinescu, F. Hammache, M. Lewitowicz, S. M. Lukyanov, J. C. Thomas, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Scattering, Projectile, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, lcsh:QC1-999, Momentum, Nuclear physics, Cross section (physics), Deep-inelastic collisions, 0103 physical sciences, Neutron, Nuclear reactions, 010306 general physics, Nuclear Experiment, Beam (structure), lcsh:Physics, Exotic nuclei
Abstract

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2 238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example. Keywords: Nuclear reactions, Deep-inelastic collisions, Exotic nuclei

Published
2018
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49. Neutron effective single-particle energies above Ni78 : A hint from lifetime measurements in the N=51 isotones Se85 and Kr87

Author

S. Leoni, R. Menegazzo, C. Fransen, A. Gottardo, V. Vandone, E. Fioretto, L. Corradi, A. Dewald, Kamila Sieja, E. Sahin, L. Sengele, G. Duchêne, A. M. Stefanini, A. Bracco, G. Montagnoli, D. Mengoni, K. Kolos, E. Ellinger, M. Hackstein, S. Lunardi, S. Franchoo, D. R. Napoli, D. Montanari, F. Recchia, J. J. Valiente-Dobón, A. I. Morales, S. Bottoni, S. M. Lenzi, A. Goasduff, D. Verney, G. de Angelis, F. Didierjean, C. Michelagnoli, L. Grocutt, F. C. L. Crespi, D. Bazzacco, J. F. Smith, J. Litzinger, Suzana Szilner, F. Scarlassara, Megumi Niikura, R. Lozeva, O. Möller, E. Farnea, T. Mijatović, V. Modamio, C. A. Ur, Sibel Zehra Aydin, and F. Ibrahim

Subjects
Physics, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, 7. Clean energy, Particle identification, Recoil, Atomic orbital, 0103 physical sciences, Particle, Neutron, AGATA, Atomic physics, 010306 general physics, Energy (signal processing)
Abstract

Background: While the $N=50$ shell-gap evolution towards $^{78}\mathrm{Ni}$ is presently in the focus of nuclear structure research, experimental information on the neutron effective single-particle energy sequence above the $^{78}\mathrm{Ni}$ core remain scarce. Direct nucleon-exchange reactions are indeed difficult with presently available post-accelerated radioactive-ion beams (especially for high orbital-momentum orbitals) in this exotic region.Purpose: In this study we probe the evolution of the $\ensuremath{\nu}1{g}_{7/2}$ effective single-particle energy which is a key to understanding the possible evolution of the spin-orbit splitting due to the proton-neutron interaction in the $^{78}\mathrm{Ni}$ region. To achieve this goal, a method based on lifetime measurements is used for the first time. The obtained lifetimes of the $7/{2}_{1}^{+}$ states in $^{87}\mathrm{Kr}$ and $^{85}\mathrm{Se}$ are used to investigate the $\ensuremath{\nu}1{g}_{7/2}$ evolution.Method: Yrast and near-yrast states in the light $N=51$ isotones $^{85}\mathrm{Se}$ and $^{87}\mathrm{Kr}$ were populated via multinucleon transfer reactions, using a $^{82}\mathrm{Se}$ beam and a $^{238}\mathrm{U}$ target at the LNL tandem-ALPI facility. The prompt $\ensuremath{\gamma}$ rays were detected by the AGATA Demonstrator and particle identification was performed using the PRISMA spectrometer. Lifetime measurements were performed by using the Cologne plunger device for deep inelastic reactions and the Recoil Distance Doppler Shift technique.Results: We obtain ${\ensuremath{\tau}}_{(7/{2}_{1}^{+})}=0.{4}_{\ensuremath{-}0.4}^{+1.6}$ ps for $^{87}\mathrm{Kr}$. In the case of $^{85}\mathrm{Se}$ an upper limit of 3(2) ps is obtained for the ${\ensuremath{\tau}}_{7/{2}_{1}^{+}}$ value.Conclusion: For $^{87}\mathrm{Kr}$, the measured $(7/{2}_{1}^{+})$ lifetime is consistent with a core-coupled ${2}^{+}\ensuremath{\bigotimes}\ensuremath{\nu}2{d}_{5/2}$ configuration for this state. This result is consistent with that obtained by direct reaction, which validates our method. For $^{85}\mathrm{Se}$, the measured $7/{2}_{1}^{+}$ lifetime limit indicates a very small contribution of the $\ensuremath{\nu}1{g}_{7/2}$ configuration to the wave function of this state.

Published
2017

50. The Low-spin Structure of $^{206}$Tl Studied by $\gamma $-ray Spectroscopy from Thermal Neutron Capture Reaction

Author

B. Fornal, Ł. W. Iskra, V. Werner, N. Cieplicka-Oryńczak, E. Ruiz-Martinez, Norbert Pietralla, Aurelien Blanc, P. Mutti, C. Michelagnoli, Michael Jentschel, F. C. L. Crespi, Ulli Köster, S. Bottoni, G. Benzoni, S. Leoni, Institut Laue-Langevin (ILL), and ILL

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Thermal neutron capture, General Physics and Astronomy, Spin structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 0103 physical sciences, Gamma spectroscopy, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

International audience; The low-spin structure of the 206Tl nucleus has been investigated with the FIPPS prompt γ-ray spectrometer of ILL making use of the 205Tl(n,γ)206Tl reaction and the γ-coincidence technique. A large number of excitations up to the neutron binding energy (at 6.5 MeV) in 206Tl were observed. Preliminary results of the data analysis provided the information on the decay scheme of the capture state in 206Tl and on the multipolarities of a number of γ rays. The comparison of the experimental data with shell-model calculations will help describing the proton–hole and neutron–hole couplings near the doubly magic core 208Pb, benchmarking single-particle levels and two-body matrix elements of the residual interaction in this important region of the nuclear chart.

Published
2017

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