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1. Diversity of shapes and rotations in the γ-soft 130Ba nucleus: First observation of a t-band in the A = 130 mass region

Author

C.M. Petrache, P.M. Walker, S. Guo, Q.B. Chen, S. Frauendorf, Y.X. Liu, R.A. Wyss, D. Mengoni, Y.H. Qiang, A. Astier, E. Dupont, R. Li, B.F. Lv, K.K. Zheng, D. Bazzacco, A. Boso, A. Goasduff, F. Recchia, D. Testov, F. Galtarossa, G. Jaworski, D.R. Napoli, S. Riccetto, M. Siciliano, J.J. Valiente-Dobon, M.L. Liu, X.H. Zhou, J.G. Wang, C. Andreoiu, F.H. Garcia, K. Ortner, K. Whitmore, T. Bäck, B. Cederwall, E.A. Lawrie, I. Kuti, D. Sohler, J. Timár, T. Marchlewski, J. Srebrny, and A. Tucholski

Subjects
Physics, QC1-999
Abstract

Several new bands have been identified in 130Ba, among which there is one with band-head spin 8+. Its properties are in agreement with the Fermi-aligned νh11/22, 7/2−[523]⊗9/2−[514] Nilsson configuration. This is the first observation of a two-quasiparticle t-band in the A=130 mass region. The t-band is fed by a dipole band involving two additional h11/2 protons. The odd-spin partners of the proton and neutron S-bands and the ground-state band at high spins are also newly identified. The observed bands are discussed using several theoretical models, total Routhians surfaces (TRS), tilted axis cranking (TAC), particle rotor model (PRM) and projected shell model (PSM), which strongly suggest the coexistence of prolate and oblate shapes polarized by rotation aligned two-proton and two-neutron configurations, as well as prolate collective rotations around axes with different orientations. With the new results, 130Ba presents one of the best and most complete sets of collective excitations that a γ-soft nucleus can manifest at medium and high spins, revealing a diversity of shapes and rotations for the nuclei in the A=130 mass region. Keywords: Nuclear structure, Collective rotations, Shape coexistence, Particle rotor model, Projected shell model, Tiltid axis cranking

Published
2019
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2. Evidence for pseudospin-chiral quartet bands in the presence of octupole correlations

Author

S. Guo, C.M. Petrache, D. Mengoni, Y.H. Qiang, Y.P. Wang, Y.Y. Wang, J. Meng, Y.K. Wang, S.Q. Zhang, P.W. Zhao, A. Astier, J.G. Wang, H.L. Fan, E. Dupont, B.F. Lv, D. Bazzacco, A. Boso, A. Goasduff, F. Recchia, D. Testov, F. Galtarossa, G. Jaworski, D.R. Napoli, S. Riccetto, M. Siciliano, J.J. Valiente-Dobon, M.L. Liu, G.S. Li, X.H. Zhou, Y.H. Zhang, C. Andreoiu, F.H. Garcia, K. Ortner, K. Whitmore, A. Ataç-Nyberg, T. Bäck, B. Cederwall, E.A. Lawrie, I. Kuti, D. Sohler, T. Marchlewski, J. Srebrny, and A. Tucholski

Subjects
Nuclear structure, Pseudospin, Chirality, Octupole correlation, Reflection-asymmetric particle rotor model, Tilted axis cranking covariant density functional theory, Physics, QC1-999
Abstract

Three nearly degenerate pairs of doublet bands are identified in 131Ba. Two of them, with positive-parity, are interpreted as pseudospin-chiral quartet bands. This is the first time that a complete set of chiral doublet bands built on the pseudospin partners π(d5/2,g7/2) is observed. The chiral bands with opposite parity built on 3-quasiparticle configurations are directly connected by many E1 transitions, without involving an intermediary non-chiral configuration. The observed band structures in 131Ba have been investigated by using the reflection-asymmetric particle rotor model. The energies and the electromagnetic transition ratios of the three pairs of doublet bands observed in 131Ba are reproduced and they are interpreted as chiral doublet bands with three-quasiparticle configurations. It is the first time that multiple chiral bands are observed in the presence of enhanced octupole correlations and pseudospin symmetry.

Published
2020
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3. High resolution gamma-ray spectrometry using GALILEO array

Author

D. Testov, J.J. Valiente-Dobon, D. Mengoni, F. Recchia, A. Goasduff, A. Boso, S. Lenzi, G. de Angelis, S. Bakes, C. Boiano, B. Cederwall, G. Colucci, M. Cicerchia, P. Colovic, F. Didierjean, M. Doncel, J.A. Duenas, F. Galtarossa, A. Gozzelino, K. Hadynska-Klek, R. Isocrate, G. Jaworski, P.R. John, H. Liu, S. Lunardi, R. Menegazzo, A. Mentana, V. Modamio, A. Nannini, D.R. Napoli, M. Palacz, G. Pasqualato, M. Rocchini, S. Riccetto, B. Saygi, E. Sahin, M. Siciliano, Yu. Sobolev, and S. Szilner

Subjects
Physics, γ -ray spectrometer, Nuclear and High Energy Physics, Radiation, Physics and Astronomy (miscellaneous), business.industry, Materials Science (miscellaneous), High resolution, γ -ray spectroscopy, nuclearstate lifetime, Condensed Matter Physics, lcsh:QC1-999, Optics, nuclear structure, Galileo (vibration training), business, lcsh:Physics, Gamma ray spectrometry
Abstract

The GALILEO γ -ray spectrometer has been constructed at the Legnaro National Laboratory of INFN (LNL-INFN). It can be coupled to advanced ancillary devices which allows nuclear structure studies employing the variety of in-beam γ -ray spectroscopy methods. Such studies benefit from reactions induced by the intense stable beams delivered by the Tandem-ALPI-PIAVE accelerator complex and by the radioactive beams which will be provided by the SPES facility. In this paper we outline two experiments performed within the experimental campaign at GALILEO coupled to the EUCLIDES Si-ball and the Neutron Wall array. The first one was aimed at spectroscopic studies in A=31 mirror nuclei and the second one at measurements of lifetimes of excited states in nuclei in the vicinity of 100 Sn.

Published
2019
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4. Collectivity at the prolate-oblate transition: The 21+ lifetime of 190W

Author

E. Şahin, V. Werner, A.K. Mistry, M. Rudigier, K. Nomura, J. Jolie, N. Pietralla, P.H. Regan, G. Ağgez, H.M. Albers, U. Ahmed, Ö. Aktaş, A. Algora, S. Alhomaidhi, C. Appleton, T. Arıcı, M. Armstrong, A. Banerjee, J. Benito, G. Benzoni, A. Blazhev, P. Boutachkov, A.M. Bruce, B. Cederwall, M.M.R. Chishti, M.L. Cortés, F. Crespi, B. Das, T. Davinson, T. Dickel, M. Doncel, A. Ertoprak, A. Esmaylzadeh, L.M. Fraile, E.R. Gamba, J. Gerl, M. Górska, J. Ha, E. Haettner, O. Hall, H. Heggen, C. Hornung, N. Hubbard, S. Jazrawi, P.R. John, C.E. Jones, V. Karayonchev, E. Kazantseva, R. Kern, L. Knafla, I. Kojouharov, P. Koseoglou, G. Kosir, D. Kostyleva, N. Kurz, N. Kuzminchuk, M. Llanos-Expósito, R. Lozeva, D. Mengoni, T.J. Mertzimekis, M. Mikolajczuk, A.I. Morales, I. Mukha, J.R. Murias, B.S. Nara-Singh, S.E.A. Orrigo, J. Pellumaj, S. Pelonis, S. Pietri, S. Pigliapoco, Zs. Podolyák, M. Polettini, K. Rezynkina, H.A. Rösch, H. Schaffner, Ch. Scheidenberger, L. Sexton, P.-A. Söderström, Y.K. Tanaka, J.J. Valiente-Dobón, P. Vasileiou, J. Vasiljević, J. Vesic, H. Weick, J. Wiederhold, A. Yaneva, G. Zhang, J. Zhao, and A. Zyriliou

Subjects
Nuclear structure, γ-ray spectroscopy, Isomer spectroscopy, Shape phase transition, DESPEC, NUSTAR, Physics, QC1-999
Abstract

The neutron-rich rare isotope 190W is discussed as a candidate for a prolate-oblate transitional nucleus with maximum γ-softness. The collectivity of this isotope is assessed for the first time by the measurement of the reduced E2 transition probability of its first 2+ state to the ground state. The experiment employed the FAst TIming Array (FATIMA), comprised of 36 LaBr3(Ce) scintillators, which was part of the DESPEC setup at GSI, Darmstadt. The 41+ and 21+ states of 190W were populated subsequently to the decay of its 127(12) μs isomeric Jπ=10− state. The mean lifetime of the 21+ state was determined to be τ=274(28) ps, which corresponds to a B(E2;21+→01+) value of 95(10) W.u. The results motivated a revision of previous calculations within an energy-density functional-based interacting boson model-2 approach, yielding E2 transition properties and spectroscopic quadrupole moments for tungsten isotopes. From comparison to theory, the new data suggest that 190W is at the transition from prolate to oblate structure along the W isotopic chain, which had previously been discussed as a nuclear shape-phase transition.

Published
2024
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5. Search for the γ decay of the narrow near-threshold proton resonance in 11B

Author

S. Bottoni, G. Corbari, S. Leoni, B. Fornal, A. Goasduff, S. Capra, D. Mengoni, E. Albanese, S. Ziliani, G. Benzoni, A.M. Sánchez-Benítez, A. Bracco, D. Brugnara, F. Camera, M. Ciemała, N. Cieplicka-Oryńczak, F.C.L. Crespi, J.A. Dueñas, A. Gadea, F. Galtarossa, E. Gamba, A. Gottardo, A. Gozzelino, J. Ha, Ł.W. Iskra, T. Marchi, R. Menegazzo, B. Million, D.R. Napoli, G. Pasqualato, J. Pellumaj, R.M. Pérez-Vidal, S. Pigliapoco, M. Polettini, C. Porzio, F. Recchia, K. Rezynkina, J.J. Valiente-Dóbon, O. Wieland, I. Zanon, and G. Zhang

Subjects
11B, Near-threshold resonance, γ-ray decay, Continuum shell model, Physics, QC1-999
Abstract

The γ decay of the elusive narrow, near-threshold proton resonance in 11B was investigated at Laboratori Nazionali di Legnaro (INFN) in a particle-γ coincidence experiment, using the 6Li(6Li,pγ) fusion-evaporation reaction and the GALILEO-GALTRACE setup. No clear signature was found for a possible E1 decay to the 1/21−, first-excited state of 11B, predicted by the Shell Model Embedded in the Continuum (SMEC) with a branching of 0.98−69+167×10−3 with respect to the dominant particle-decaying modes. The statistical analysis of the γ-ray spectrum provided an average upper limit of 2.37×10−3 for this γ-ray branching, with a global significance of 5σ. On the other hand, by imposing a global confidence level of 3σ, a significant excess of counts was observed for E=γ9300(20) keV, corresponding to a resonance energy of 11429(20) keV (namely 200(20) keV above the proton separation energy of 11B) and a γ-ray branching of 1.12(35)×10−3. This result is compatible with the SMEC calculations, potentially supporting the existence of a near-threshold proton resonance in 11B.

Published
2024
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6. Octupole correlations in the N = Z + 2 = 56 110Xe nucleus

Author

A. Illana, R.M. Pérez-Vidal, D. Stramaccioni, J.J. Valiente-Dobón, T.R. Rodriguez, L.M. Robledo, A. Poves, K. Auranen, O. Beliuskina, C. Delafosse, T. Eronen, Z. Ge, S. Geldhof, W. Gins, T. Grahn, P.T. Greenlees, H. Joukainen, R. Julin, H. Jutila, A. Kankainen, M. Leino, J. Louko, M. Luoma, D. Nesterenko, J. Ojala, J. Pakarinen, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, J. Uusitalo, and G.L. Zimba

Subjects
Octupole deformations, 110Xe, N=Z=56 region, Fusion evaporation reactions, Physics, QC1-999
Abstract

This letter reports on the first observation of an octupole band in the neutron-deficient (N=Z+2) nucleus 110Xe. The 110Xe nuclei were produced via the 54Fe(58Ni,2n) fusion-evaporation reaction. The emitted γ rays were detected using the jurogam 3 γ-ray spectrometer, while the fusion-evaporation residues were separated with the MARA separator at the Accelerator Laboratory of the University of Jyväskylä, Finland. The experimental observation of the low-lying 3− and 5− states and inter-band E1 transitions between the ground-state band and the octupole band proves the importance of octupole correlations in this region. These new experimental data combined with theoretical calculations using the symmetry-conserving configuration-mixing method, based on a Gogny energy density functional, have been interpreted as an evidence of enhanced octupole correlations in neutron-deficient xenon isotopes.

Published
2024
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7. An alternative viewpoint on the nuclear structure towards 100Sn: Lifetime measurements in 105Sn

Author

G. Pasqualato, A. Gottardo, D. Mengoni, A. Goasduff, J.J. Valiente-Dobón, F. Nowacki, S. Péru, N. Pillet, G. de Angelis, S.D. Bakes, T. Bayram, D. Bazzacco, G. Benzoni, D. Brugnara, M. Cicerchia, P. Colovic, M.L. Cortés, A. Gadea, F. Galtarossa, M. Górska, A. Gozzelino, E. Gregor, N. Hubbard, A. Illana, M. Jurado, S.M. Lenzi, G. Mantovani, T. Marchi, R. Menegazzo, A. Montaner-Pizá, D.R. Napoli, F. Recchia, M. Siciliano, D. Testov, S. Szilner, and I. Zanon

Subjects
Nuclear structure, γ-ray spectroscopy, Transition probabilities, Neutron-deficient isotopes, Odd-mass nuclei, Lifetime measurements, Physics, QC1-999
Abstract

This work aims at presenting an alternative approach to the long standing problem of the B(E2) values in Sn isotopes in the vicinity of the N=Z double-magic nucleus 100Sn, until now predominantly measured with relativistic and intermediate-energy Coulomb excitation reactions. The direct measurement of the lifetime of low-lying excited states in odd-even Sn isotopes provides a new and precise guidance for the theoretical description of the nuclear structure in this region. Lifetime measurements have been performed in 105Sn for the first time with the coincidence Recoil Distance Doppler Shift technique. The lifetime results for the 7/21+ first excited state and the 11/21+ state, 2+(104Sn) ⊗ν1g7/2 multiplet member, are discussed in comparison with state-of-the-art shell model and mean field calculations, highlighting the crucial contribution of proton excitation across the core of 100Sn. The reduced transition probability B(E2) of the 11/21+ core-coupled state points out an enhanced staggering with respect to the B(E2; 21+→01+) in the even-mass 104Sn and 106Sn isotopes.

Published
2023
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8. Emergence of triaxiality in 74Se from electric monopole transition strengths

Author

N. Marchini, A. Nannini, M. Rocchini, T.R. Rodríguez, M. Ottanelli, N. Gelli, A. Perego, G. Benzoni, N. Blasi, G. Bocchi, D. Brugnara, A. Buccola, G. Carozzi, A. Goasduff, E.T. Gregor, P.R. John, M. Komorowska, D. Mengoni, F. Recchia, S. Riccetto, D. Rosso, A. Saltarelli, M. Siciliano, J.J. Valiente-Dobón, and I. Zanon

Subjects
Electric monopole (E0) transitions, Internal conversion, Nuclear structure, Physics, QC1-999
Abstract

The structure of 74Se at low energy was investigated via spectroscopy of internal conversion electrons at the INFN Legnaro National Laboratories (LNL). A set of internal K-conversion coefficients and monopole transition strengths was measured. A large ρ2(E0;22+→21+)⋅103=210(130) value was deduced. This result, in addition to a low upper limit for the 03+→02+ electron transition, casts in doubt a simple interpretation of the 74Se low-lying structure, in particular the recently proposed spherical, vibrational character. New microscopic beyond-mean-field calculations generally agree with the experimental results and are capable of producing a large ρ2(E0;22+→21+) value, even if still a factor ≈7 smaller than the experiment. Triaxiality and a complex shape-coexistence and mixing scenario seem responsible for this unexpected experimental result.

Published
2023
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9. Lifetime measurments of excited states in neutron-rich fission fragments

Author

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

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

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

Published
2015
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10. A digital front-end electronics for the neutron detector NEDA

Author

F.J. Egea, C. Houarner, A. Boujrad, V. Gonzalez, M. Tripon, M. Jastrzab, A. Triossi, G. de France, A. Gadea, J.J. Valiente-Dobon, E. Sanchis, D. Barrientos, M. Blaizot, P. Bourgault, G. de Angelis, M.N. Erduran, S. Erturk, T. Huyuk, G. Jaworski, X.L. Luo, V. Modamio, M. Moszynski, A. Di Nitto, J. Nyberg, P-A. Soderstrom, M. Palacz, and R. Wadsworth

Published
2014
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11. Preface

Author

S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, and J.J. Valiente-Dobon

Subjects
Physics, QC1-999
Published
2014

12. Dalitz Plot analysis for η → π+π-π0 at KLOE

Author

R. Menegazzo, Andrea Dainese, A. Nannini, P. Di Nezza, P. G. Bizzeti, J.J. Valiente-Dobon, Massimo Chiari, L. Caldeira Balkeståhl, S. Lunardi, C. Bucci, and C. Signorini

Subjects
Physics, QC1-999
Abstract

We present the status of an ongoing analysis of the η → π+π−π0 Dalitz plot, as well as preliminary results for the Dalitz plot parameters. The analysis is based on data taken at the DAΦNE φ-factory with the KLOE detector.

Published
2014

13. A new front-end high-resolution sampling board for the new-generation electronics of EXOGAM2 and NEDA detectors

Author

F.J. Egea, V. Gonzalez, M. Tripon, M. Jastrzab, A. Triossi, A. Gadea, G. de France, J.J. Valiente-Dobon, J.M. Blasco, D. Barrientos, E. Sanchis, A. Boujrad, C. Houarner, M. Blaizot, P. Bourgault, G. de Angelis, M.N. Erduran, S. Erturk, T. Huyuk, G. Jaworski, X.L. Luo, V. Modamio, M. Moszynski, A. Di Nitto, J. Nyberg, P-A. Soderstrom, M. Palacz, R. Wadsworth, Triossi, Andrea -- 0000-0001-5140-9154, Di Nitto, Antonio -- 0000-0002-9319-366X, Huyuk, Tayfun -- 0000-0003-0597-9767, and [Egea, F. J. -- Gonzalez, V. -- Sanchis, E.] Univ Valencia, Dept Elect Engn, Escola Tecn Super Engn, Burjassot, Valencia, Spain -- [Gadea, A. -- Barrientos, D. -- Huyuk, T.] Inst Fis Corpuscular CSIC UV, Valencia, Spain -- [Tripon, M. -- de France, G. -- Boujrad, A. -- Houarner, C. -- Blaizot, M. -- Bourgault, P.] GANIL, F-14706 Caen, France -- [Jastrzab, M.] Polish Acad Sci, Niewodniczanski Inst Nucl Phys, Krakow, Poland -- [Triossi, A. -- Valiente-Dobon, J. J. -- Barrientos, D. -- de Angelis, G. -- Modamio, V.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, IT-35020 Padua, Italy -- [Jaworski, G.] Warsaw Univ Technol, Fac Phys, Warsaw, Poland -- [Jaworski, G. -- Moszynski, M. -- Palacz, M.] Univ Warsaw, Heavy Ion Lab, Warsaw, Poland -- [Luo, X. L. -- Nyberg, J. -- Soderstrom, P-A.] Uppsala Univ, Dept Phys & Astron, Uppsala, Sweden -- [Moszynski, M.] Natl Ctr Nucl Res, PL-05400 Otwock, Poland -- [Luo, X. L.] Natl Univ Def Technol, Dept Instrument Sci & Technol, Changsha, Hunan, Peoples R China -- [Soderstrom, P-A.] RIKEN Nishina Ctr, Wako, Saitama, Japan -- [Di Nitto, A.] Johannes Gutenberg Univ Mainz, D-55099 Mainz, Germany -- [Erduran, M. N.] Istanbul Sabahattin Zaim Univ, Fac Engn & Nat Sci, Istanbul, Turkey -- [Erturk, S.] Nigde Univ, Fen Edebiyat Falkultesi, Fiz Bolumu, Nigde, Turkey -- [Wadsworth, R.] Univ York, Dept Phys, York, N Yorkshire, England

Abstract

19th IEEE-NPSS Real Time Conference (RT) -- MAY 26-30, 2014 -- Nara, JAPAN, WOS: 000380588000136, The present paper aims to present the final design and results of the FADC Mezzanine for EXOGAM and NEDA detectors, focusing on the resolution performance. Finally, the conclusion shows how a common digitizing device has been integrated in an experimental environment involving low-noise and fast sampling rates. Not only the integration fulfilled the expected specifications on both systems, but also, it shows how a study of synergy between detectors has led to a reduction of resources and time by applying a common strategy., Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc

Published
2014

14. High-spin states in 212Po above the α-decaying (18+) isomer

Author

L. Zago, A. Gottardo, J.J. Valiente-Dobón, G. Benzoni, A. Gadea, M. Górska, S. Lunardi, Zs. Podolyák, P.H. Regan, D. Rudolph, A. Algora, G. de Angelis, D. Bazzacco, J. Benlliure, P. Boutachkov, A. Bracco, A.M. Bruce, F. Camera, E. Casarejos, M.L. Cortés, F.C.L. Crespi, A. Corsi, C. Domingo-Pardo, M. Doncel, T. Engert, H. Geissel, J. Gerl, A. Goasduff, N. Goel, J. Grebosz, E. Gregor, T. Habermann, S. Klupp, I. Kojouharov, N. Kurz, S.M. Lenzi, S. Leoni, S. Mandal, R. Menegazzo, D. Mengoni, B. Million, A.I. Morales, D.R. Napoli, F. Naqvi, C. Nociforo, M. Pfützner, S. Pietri, A. Prochazka, F. Recchia, E. Sahin, H. Schaffner, A. Sharma, B. Sitar, D. Siwal, P. Strmen, I. Szarka, C.A. Ur, P.M. Walker, H. Weick, O. Wieland, and H.-J. Wollersheim

Subjects
γ spectroscopy, Isomer spectroscopy, High-spin spectroscopy, Physics, QC1-999
Abstract

The nucleus 212Po has been produced through the fragmentation of a 238U primary beam at 1 GeV/nucleon at GSI, separated with the FRagment Separator, FRS, and studied via isomer γ-decay spectroscopy with the RISING setup. Two delayed previously unknown γ rays have been observed. One has been attributed to the E3 decay of a 21− isomeric state feeding the α-emitting 45-s (18+) high-spin isomer. The other γ-ray line has been assigned to the decay of a higher-lying 23+ metastable state. These are the first observations of high-spin states above the 212Po (18+) isomer, by virtue of the selectivity obtained via ion-by-ion identification of 238U fragmentation products. Comparison with shell-model calculations points to shortfalls in the nuclear interactions involving high-j proton and neutron orbitals, to which the region around Z∼100 is sensitive.

Published
2022
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15. Design and Test of a High-speed Flash ADC Mezzanine Card for High-resolution and Timing Performance in Nuclear Structure Experiments

Author

X. Egea, E. Sanchis, V. Gonzalez, A. Gadea, J.M. Blasco, D. Barrientos, J.J. Valiente Dobon, M. Tripon, A. Boujrad, C. Houarner, M. Jastrzab, M. Blaizot, P. Bourgault, G. de Angelis, M.N. Erduran, S. Erturk, G. de France, T. Huyuk, G. Jaworski, A. di Nitto, J. Nyberg, M. Palacz, A. Pipidis, R. Tarnowski, A. Triossi, R. Wadsworth, 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), EXOGAM, Egea, X., Sanchis, E., Gonzalez, V., Gadea, A., Blasco, J. M., Barrientos, D., Valiente Dobon, J. J., Tripon, M., Boujrad, A., Houarner, C., Jastrzab, M., Blaizot, M., Bourgault, P., De Angelis, G., Erduran, M. N., Erturk, S., De France, G., Huyuk, T., Jaworski, G., DI NITTO, Antonio, Nyberg, J., Palacz, M., Pipidis, A., Tarnowski, R., Triossi, A., and Wadsworth, R.

Subjects
Computer science, business.industry, Physics::Instrumentation and Detectors, High resolution, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Flash ADC, business, Computer hardware, Test (assessment)
Abstract

International audience; This board will be part of the upgrade for the new electronics for the EXOGAM2 (HP-Ge detector array) and NEDA (BC501A-based neutron detector array), therefore it was necessary to deal with the problem of providing a sampling card with high resolution for new gamma spectroscopy experiments while sampling at very high rates, with a broad bandwidth in order to preserve the shape for further analysis. Pulse shape analysis is of paramount importance in neutron detectors, such as NEDA, based on scintillators that are sensitive to γ-rays as well. High resolution and high speed are often two parameters which conform a trade-off and it is hard to achieve both simultaneously. The aforementioned constraints and the urge of building new sampling electronics to improve the signal analysis in nuclear physics experiments, led to the development of this FADC mezzanine This involves sampling rates up to 250 Msps preserving a high resolution of 11.3 effective bits in order to satisfy the experiment demands. In this work is described the design and the test bench proposed for a proper high speed ADC characterization system and the results obtained up to now.

Published
2012
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16. Identification of intruderπi13/2state in197Tl

Author

J.J. Valiente-Dobon, S. Mukhopadhyay, S. Rajbanshi, Srijit Bhattacharya, T. Bhattacharjee, G. Mukherjee, Massimo Chiari, P. G. Bizzeti, Surajit Pal, R. Menegazzo, M. Gohil, C. Signorini, J. K. Meena, H. Pai, Deepak Pandit, A. Nannini, P. Mukhopadhyay, S. Lunardi, T. K. Ghosh, K. Banerjee, R. Pandey, Andrea Dainese, P. Di Nezza, C. Bucci, S. Kundu, G. Prajapati, T. K. Rana, S. Bhattacharyya, S.R. Banerjee, A. Choudhury, Avijit Goswami, C. Bhattacharya, and S. Chanda

Subjects
Physics, QC1-999, Identification (biology), Computational biology, Nuclear Experiment
Abstract

The high-spin states in 197Tl were studied by populating them using the 197Au(α, 4n)197 Tl reaction at 48 MeV of beam energy. γ−γ coincidence data were taken using a combination of clover, LEPS (low energy photon spectrometer) and single crystal HPGe detectors. The polarization and DCO measurements were performed for definite spin and parity assignment of the excited states. The πi13/2 intruder state has been identified for the first time in this nucleus. The total Routhian surface calculations have been performed to study the shape and deformation of 197Tl for different configurations.

Published
2014
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17. Lifetime measurements of excited states in 169,171,173Os: Persistence of anomalous B(E2) ratios in transitional rare earth nuclei in the presence of a decoupled i13/2 valence neutron

Author

W. Zhang, B. Cederwall, M. Doncel, Ö. Aktas, A. Ertoprak, R. Liotta, C. Qi, T. Grahn, B.S. Nara Singh, D.M. Cullen, D. Hodge, M. Giles, S. Stolze, H. Badran, T. Braunroth, T. Calverley, D.M. Cox, Y.D. Fang, P.T. Greenlees, J. Hilton, E. Ideguchi, R. Julin, S. Juutinen, M. Kumar Raju, H. Li, H. Liu, S. Matta, P. Subramaniam, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, C.M. Petrache, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, M.J. Taylor, J. Uusitalo, and J.J. Valiente-Dobón

Subjects
Physics, QC1-999
Abstract

Lifetimes of low-lying excited states in the νi13/2+ bands of the neutron-deficient osmium isotopes 169,171,173Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) in 169Os, similar to the “anomalously” low values of the ratio B(E2;41+→21+)/B(E2;21+→0gs+) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring 168,170Os. Furthermore, the evolution of B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) with increasing neutron number in the odd-mass isotopic chain 169,171,173Os is observed to follow the same trend as observed previously in the even-even Os isotopes. These findings indicate that the possible quantum phase transition from a seniority conserving structure to a collective regime as a function of neutron number suggested for the even-even systems is maintained in these odd-mass osmium nuclei, with the odd valence neutron merely acting as a “spectator”. As for the even-even nuclei, the phenomenon is highly unexpected for nuclei that are not situated near closed shells.

Published
2021
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18. Manifestation of the Berry phase in the atomic nucleus 213Pb

Author

J.J. Valiente-Dobón, A. Gottardo, G. Benzoni, A. Gadea, S. Lunardi, A. Algora, G. de Angelis, D. Bazzacco, J. Benlliure, P. Boutachkov, A. Bracco, A.M. Bruce, F. Camera, E. Casarejos, M.L. Cortés, F.C.L. Crespi, A. Corsi, C. Domingo-Pardo, M. Doncel, T. Engert, H. Geissel, J. Gerl, A. Goasduff, N. Goel, M. Górska, J. Grebosz, E. Gregor, T. Habermann, S. Klupp, I. Kojouharov, N. Kurz, S.M. Lenzi, S. Leoni, S. Mandal, R. Menegazzo, D. Mengoni, B. Million, A.I. Morales, D.R. Napoli, F. Naqvi, C. Nociforo, M. Pfützner, S. Pietri, Zs. Podolyák, A. Prochazka, F. Recchia, P.H. Regan, D. Rudolph, E. Sahin, H. Schaffner, A. Sharma, B. Sitar, D. Siwal, P. Strmen, I. Szarka, C.A. Ur, P.M. Walker, H. Weick, O. Wieland, H.-J. Wollersheim, and P. Van Isacker

Subjects
Physics, QC1-999
Abstract

The neutron-rich 213Pb isotope was produced in the fragmentation of a primary 1 GeV A 238U beam, separated in FRS in mass and atomic number, and then implanted for isomer decay γ-ray spectroscopy with the RISING setup at GSI. A newly observed isomer and its measured decay properties indicate that states in 213Pb are characterized by the seniority quantum number that counts the nucleons not in pairs coupled to angular momentum J=0. The conservation of seniority is a consequence of a geometric phase associated with particle-hole conjugation, which becomes observable in semi-magic nuclei where nucleons half-fill the valence shell. The γ-ray spectroscopic observables in 213Pb are thus found to be driven by two mechanisms, particle-hole conjugation and seniority conservation, which are intertwined through a Berry phase.

Published
2021
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19. Low-lying electric dipole γ-continuum for the unstable 62,64Fe nuclei: Strength evolution with neutron number

Author

R. Avigo, O. Wieland, A. Bracco, F. Camera, F. Ameil, T. Arici, A. Ataç, D. Barrientos, D. Bazzacco, P. Bednarczyk, G. Benzoni, B. Birkenbach, N. Blasi, H.C. Boston, S. Bottoni, S. Brambilla, B. Bruyneel, M. Ciemała, E. Clément, M.L. Cortés, F.C.L. Crespi, D.M. Cullen, D. Curien, F. Didierjean, C. Domingo-Pardo, G. Duchêne, J. Eberth, A. Görgen, A. Gadea, J. Gerl, N. Goel, P. Golubev, V. González, M. Górska, A. Gottardo, E. Gregor, G. Guastalla, T. Habermann, L.J. Harkness-Brennan, A. Jungclaus, M. Kmiecik, I. Kojouharov, W. Korten, N. Kurz, M. Labiche, N. Lalović, S. Leoni, M. Lettmann, A. Maj, R. Menegazzo, D. Mengoni, E. Merchan, B. Million, A.I. Morales, D.R. Napoli, C. Nociforo, J. Nyberg, N. Pietralla, S. Pietri, Zs. Podolyák, V.Yu. Ponomarev, A. Pullia, B. Quintana, G. Rainovski, D. Ralet, F. Recchia, M. Reese, P. Regan, P. Reiter, S. Riboldi, D. Rudolph, M.D. Salsac, E. Sanchis, L.G. Sarmiento, H. Schaffner, J. Simpson, O. Stezowski, J.J. Valiente-Dobón, and H.J. Wollersheim

Subjects
64Fe, 62Fe, Nuclear structure, Dipole excitation around neutron threshold, Physics, QC1-999
Abstract

The γ-ray emission from the nuclei 62,64Fe 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 62,64Fe 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.

Published
2020
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20. Pairing-quadrupole interplay in the neutron-deficient tin nuclei: First lifetime measurements of low-lying states in 106,108Sn

Author

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

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

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

Published
2020
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21. Is seniority a partial dynamic symmetry in the first νg9/2 shell?

Author

A.I. Morales, G. Benzoni, H. Watanabe, G. de Angelis, S. Nishimura, L. Coraggio, A. Gargano, N. Itaco, T. Otsuka, Y. Tsunoda, P. Van Isacker, F. Browne, R. Daido, P. Doornenbal, Y. Fang, G. Lorusso, Z. Patel, S. Rice, L. Sinclair, P.-A. Söderström, T. Sumikama, J.J. Valiente-Dobón, J. Wu, Z.Y. Xu, A. Yagi, R. Yokoyama, H. Baba, R. Avigo, F.L. Bello Garrote, N. Blasi, A. Bracco, A.M. Bruce, F. Camera, S. Ceruti, F.C.L. Crespi, M.-C. Delattre, Zs. Dombradi, A. Gottardo, T. Isobe, I. Kojouharov, N. Kurz, I. Kuti, S. Lalkovski, K. Matsui, B. Melon, D. Mengoni, T. Miyazaki, V. Modamio-Hoybjor, S. Momiyama, D.R. Napoli, M. Niikura, R. Orlandi, Zs. Podolyák, P.H. Regan, H. Sakurai, E. Sahin, D. Sohler, H. Schaffner, R. Taniuchi, J. Taprogge, Zs. Vajta, O. Wieland, and M. Yalcinkaya

Subjects
Physics, QC1-999
Abstract

The low-lying structures of the midshell νg9/2 Ni isotopes 72Ni and 74Ni have been investigated at the RIBF facility in RIKEN within the EURICA collaboration. Previously unobserved low-lying states were accessed for the first time following β decay of the mother nuclei 72Co and 74Co. As a result, we provide a complete picture in terms of the seniority scheme up to the first (8+) levels for both nuclei. The experimental results are compared to shell-model calculations in order to define to what extent the seniority quantum number is preserved in the first neutron g9/2 shell. We find that the disappearance of the seniority isomerism in the (81+) states can be explained by a lowering of the seniority-four (6+) levels as predicted years ago. For 74Ni, the internal de-excitation pattern of the newly observed (62+) state supports a restoration of the normal seniority ordering up to spin J=4. This property, unexplained by the shell-model calculations, is in agreement with a dominance of the single-particle spherical regime near 78Ni.

Published
2018
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22. Type II shell evolution in A=70 isobars from the N≥40 island of inversion

Author

A.I. Morales, G. Benzoni, H. Watanabe, Y. Tsunoda, T. Otsuka, S. Nishimura, F. Browne, R. Daido, P. Doornenbal, Y. Fang, G. Lorusso, Z. Patel, S. Rice, L. Sinclair, P.-A. Söderström, T. Sumikama, J. Wu, Z.Y. Xu, A. Yagi, R. Yokoyama, H. Baba, R. Avigo, F.L. Bello Garrote, N. Blasi, A. Bracco, F. Camera, S. Ceruti, F.C.L. Crespi, G. de Angelis, M.-C. Delattre, Zs. Dombradi, A. Gottardo, T. Isobe, I. Kojouharov, N. Kurz, I. Kuti, K. Matsui, B. Melon, D. Mengoni, T. Miyazaki, V. Modamio-Hoybjor, S. Momiyama, D.R. Napoli, M. Niikura, R. Orlandi, H. Sakurai, E. Sahin, D. Sohler, H. Schaffner, R. Taniuchi, J. Taprogge, Zs. Vajta, J.J. Valiente-Dobón, O. Wieland, and M. Yalcinkaya

Subjects
Physics, QC1-999
Abstract

The level structures of 70Co and 70Ni, populated from the β decay of 70Fe, have been investigated using β-delayed γ-ray spectroscopy following in-flight fission of a 238U beam. The experimental results are compared to Monte-Carlo Shell-Model calculations including the pf+g9/2+d5/2 orbitals. The strong population of a (1+) state at 274 keV in 70Co is at variance with the expected excitation energy of ∼1 MeV from near spherical single-particle estimates. This observation indicates a dominance of prolate-deformed intruder configurations in the low-lying levels, which coexist with the normal near spherical states. It is shown that the β decay of the neutron-rich A=70 isobars from the new island of inversion to the Z=28 closed-shell regime progresses in accordance with a newly reported type of shell evolution, the so-called Type II, which involves many particle-hole excitations across energy gaps.

Published
2017
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23. Interplay of quasiparticle and vibrational excitations: First observation of isomeric states in 168Dy and 169Dy

Author

G.X. Zhang, H. Watanabe, G.D. Dracoulis, F.G. Kondev, G.J. Lane, P.H. Regan, P.-A. Söderström, P.M. Walker, K. Yoshida, H. Kanaoka, Z. Korkulu, P.S. Lee, J.J. Liu, S. Nishimura, J. Wu, A. Yagi, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, M.P. Carpenter, R.J. Carroll, K.Y. Chae, C.J. Chiara, Zs. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, T. Lauritsen, C.S. Lee, E.J. Lee, C.J. Lister, G. Lorusso, G. Lotay, E.A. McCutchan, C.-B. Moon, I. Nishizuka, C.R. Nita, A. Odahara, Z. Patel, V.H. Phong, Zs. Podolyák, O.J. Roberts, H. Sakurai, H. Schaffner, D. Seweryniak, C.M. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dóbon, Z.Y. Xu, and S. Zhu

Subjects
Physics, QC1-999
Abstract

The neutron-rich dysprosium isotopes 168Dy102 and 169Dy103 have been investigated using the EURICA γ-ray spectrometer, following production via in-flight fission of a high-intensity uranium beam in conjunction with isotope separation through the BigRIPS separator at RIBF in RIKEN Nishina Center. For 168Dy, a previously unreported isomer with a half-life of 0.57(7) μs has been identified at an excitation energy of 1378 keV, and its presence affirmed independently using γ-γ-γ coincidence data taken with Gammasphere via two-proton transfer from an enriched 170Er target performed at Argonne National Laboratory. This isomer is assigned Jπ=Kπ=(4−) based on the measured transition strengths, decay patterns, and the energy systematics for two-quasiparticle states in N=102 isotones. The underlying mechanism of two-quasiparticle excitations in the doubly midshell region is discussed in comparison with the deformed QRPA and multi-quasiparticle calculations. In 169Dy, the B(E2) value for the transition de-exciting the previously unreported Kπ=(1/2−) isomeric state at 166 keV to the Kπ=(5/2−) ground state is approximately two orders of magnitude larger than the E2 strength for the corresponding isomeric-decay transition in the N=103 isotone 173Yb, suggesting the presence of a significant γ-vibrational admixture with a dominant neutron one-quasiparticle component in the isomeric state.

Published
2019
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24. Isospin dependence of electromagnetic transition strengths among an isobaric triplet

Author

A. Boso, S.A. Milne, M.A. Bentley, F. Recchia, S.M. Lenzi, D. Rudolph, M. Labiche, X. Pereira-Lopez, S. Afara, F. Ameil, T. Arici, S. Aydin, M. Axiotis, D. Barrientos, G. Benzoni, B. Birkenbach, A.J. Boston, H.C. Boston, P. Boutachkov, A. Bracco, A.M. Bruce, B. Bruyneel, B. Cederwall, E. Clement, M.L. Cortes, D.M. Cullen, P. Désesquelles, Zs. Dombràdi, C. Domingo-Pardo, J. Eberth, C. Fahlander, M. Gelain, V. González, P.R. John, J. Gerl, P. Golubev, M. Górska, A. Gottardo, T. Grahn, L. Grassi, T. Habermann, L.J. Harkness-Brennan, T.W. Henry, H. Hess, I. Kojouharov, W. Korten, N. Lalović, M. Lettmann, C. Lizarazo, C. Louchart-Henning, R. Menegazzo, D. Mengoni, E. Merchan, C. Michelagnoli, B. Million, V. Modamio, T. Moeller, D.R. Napoli, J. Nyberg, B.S. Nara Singh, H. Pai, N. Pietralla, S. Pietri, Zs. Podolyak, R.M. Perez Vidal, A. Pullia, D. Ralet, G. Rainovski, M. Reese, P. Reiter, M.D. Salsac, E. Sanchis, L.G. Sarmiento, H. Schaffner, L.M. Scruton, P.P. Singh, C. Stahl, S. Uthayakumaar, J.J. Valiente-Dobón, and O. Wieland

Subjects
Physics, QC1-999
Abstract

Electric quadrupole matrix elements, Mp, for the Jπ=2+→0+, ΔT=0, T=1 transitions across the A=46 isobaric multiplet 46Cr-46V-46Ti have been measured at GSI with the FRS-LYCCA-AGATA setup. This allows direct insight into the isospin purity of the states of interest by testing the linearity of Mp with respect to Tz. Pairs of nuclei in the T=1 triplet were studied using identical reaction mechanisms in order to control systematic errors. The Mp values were obtained with two different methodologies: (i) a relativistic Coulomb excitation experiment was performed for 46Cr and 46Ti; (ii) a “stretched target” technique was adopted here, for the first time, for lifetime measurements in 46V and 46Ti. A constant value of Mp across the triplet has been observed. Shell-model calculations performed within the fp shell fail to reproduce this unexpected trend, pointing towards the need of a wider valence space. This result is confirmed by the good agreement with experimental data achieved with an interaction which allows excitations from the underlying sd shell. A test of the linearity rule for all published data on complete T=1 isospin triplets is presented.

Published
2019
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25. K-mixing in the doubly mid-shell nuclide 170Dy and the role of vibrational degeneracy

Author

P.-A. Söderström, P.M. Walker, J. Wu, H.L. Liu, P.H. Regan, H. Watanabe, P. Doornenbal, Z. Korkulu, P. Lee, J.J. Liu, G. Lorusso, S. Nishimura, V.H. Phong, T. Sumikama, F.R. Xu, A. Yagi, G.X. Zhang, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, R.J. Carroll, K.Y. Chae, Zs. Dombradi, A. Estrade, N. Fukuda, C.J. Griffin, E. Ideguchi, N. Inabe, T. Isobe, H. Kanaoka, S. Kanaya, I. Kojouharov, F.G. Kondev, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, G.J. Lane, E.J. Lee, C.S. Lee, G. Lotay, C.-B. Moon, I. Nishizuka, C.R. Niţă, A. Odahara, Z. Patel, Zs. Podolyák, O.J. Roberts, H. Sakurai, H. Schaffner, C.M. Shand, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dòbon, and Z.Y. Xu

Subjects
Physics, QC1-999
Abstract

A detailed study of the structure of the doubly mid-shell nucleus Dy104166170 has been carried out, following isomeric and β decay. We have measured the yrast band up to the spin-parity Jπ=6+ state, the K=2 γ-vibration band up to the 5+ state, a low-lying negative-parity band based on a 2− state that could be a candidate for the lowest energy octupole vibration state within this nucleus, and a candidate for the Kπ=6+ two quasi-particle isomer. This state was determined to have an excitation energy of 1643.91(23) keV and a half life of 0.99(4) μs, with a reduced hindrance for its decay to the ground-state band an order of magnitude lower than predicted by NpNn systematics. This is interpreted as being due to γ-vibrational mixing from a near degeneracy of the isomer and the 6+ state of the γ band. Furthermore, the parent nucleus 170Tb has been determined to have a half-life of 0.91(−13+18) s with a possible spin-parity of 2−. Keywords: K isomer, Dysprosium, Mid-shell, γ-Ray spectroscopy

Published
2016
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26. Long-lived K isomer and enhanced γ vibration in the neutron-rich nucleus 172Dy: Collectivity beyond double midshell

Author

H. Watanabe, G.X. Zhang, K. Yoshida, P.M. Walker, J.J. Liu, J. Wu, P.H. Regan, P.-A. Söderström, H. Kanaoka, Z. Korkulu, P.S. Lee, S. Nishimura, A. Yagi, D.S. Ahn, T. Alharbi, H. Baba, F. Browne, A.M. Bruce, R.J. Carroll, K.Y. Chae, Zs. Dombradi, P. Doornenbal, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N. Inabe, T. Isobe, S. Kanaya, I. Kojouharov, F.G. Kondev, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, G.J. Lane, C.S. Lee, E.J. Lee, G. Lorusso, G. Lotay, C.-B. Moon, I. Nishizuka, C.R. Nita, A. Odahara, Z. Patel, V.H. Phong, Zs. Podolyák, O.J. Roberts, H. Sakurai, H. Schaffner, C.M. Shand, Y. Shimizu, T. Sumikama, H. Suzuki, H. Takeda, S. Terashima, Zs. Vajta, J.J. Valiente-Dóbon, and Z.Y. Xu

Subjects
172Dy, K isomer, Decay spectroscopy, Axial symmetry, γ vibration, Physics, QC1-999
Abstract

The level structure of 172Dy has been investigated for the first time by means of decay spectroscopy following in-flight fission of a 238U beam. A long-lived isomeric state with T1/2=0.71(5) s and Kπ=8− has been identified at 1278 keV, which decays to the ground-state and γ-vibrational bands through hindered electromagnetic transitions, as well as to the daughter nucleus 172Ho via allowed β decays. The robust nature of the Kπ=8− isomer and the ground-state rotational band reveals an axially-symmetric structure for this nucleus. Meanwhile, the γ-vibrational levels have been identified at unusually low excitation energy compared to the neighboring well-deformed nuclei, indicating the significance of the microscopic effect on the non-axial collectivity in this doubly mid-shell region. The underlying mechanism of enhanced γ vibration is discussed in comparison with the deformed Quasiparticle Random-Phase Approximation based on a Skyrme energy-density functional.

Published
2016
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27. Decay properties of 68,69,70Mn: Probing collectivity up to N=44 in Fe isotopic chain

Author

G. Benzoni, A.I. Morales, H. Watanabe, S. Nishimura, L. Coraggio, N. Itaco, A. Gargano, F. Browne, R. Daido, P. Doornenbal, Y. Fang, G. Lorusso, Z. Patel, S. Rice, L. Sinclair, P.-A. Söderström, T. Sumikama, J. Wu, Z.Y. Xu, R. Yokoyama, H. Baba, R. Avigo, F.L. Bello Garrote, N. Blasi, A. Bracco, F. Camera, S. Ceruti, F.C.L. Crespi, G. de Angelis, M.-C. Delattre, Zs. Dombradi, A. Gottardo, T. Isobe, I. Kuti, K. Matsui, B. Melon, D. Mengoni, T. Miyazaki, V. Modamio-Hoybjor, S. Momiyama, D.R. Napoli, M. Niikura, R. Orlandi, H. Sakurai, E. Sahin, D. Sohler, R. Taniuchi, J. Taprogge, Zs. Vajta, J.J. Valiente-Dobón, O. Wieland, and M. Yalcinkaya

Subjects
Physics, QC1-999
Abstract

The β decays Mn68→Fe68, Mn69→Fe69 and Mn70→Fe70 have been measured at the RIBF facility at RIKEN using the EURICA γ spectrometer combined with an active stopper consisting of a stack of Si detectors. The nuclei were produced as fission fragments from a beam of 238U at a bombarding energy of 345 MeV/nucleon impinging on a Be target and selected using the BigRIPS separator. Half-lives and β-delayed neutron emission probabilities have been extracted for these decays, together with first experimental information on excited states populated in 69,70Fe. The data indicate a continuously increasing deformation for Fe isotopes up to A=70. This is interpreted, as for Cr isotopes, in terms of the interplay between the quadrupole correlations of the ν1d5/2 and ν0g9/2 orbitals and the monopole component of the π0f7/2–ν0f5/2 interaction.

Published
2015
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28. Evidence of octupole-phonons at high spin in 207Pb

Author

D. Ralet, E. Clément, G. Georgiev, A.E. Stuchbery, M. Rejmund, P. Van Isacker, G. de France, A. Lemasson, J. Ljungvall, C. Michelagnoli, A. Navin, D.L. Balabanski, L. Atanasova, A. Blazhev, G. Bocchi, R. Carroll, J. Dudouet, E. Dupont, B. Fornal, S. Franchoo, C. Fransen, C. Müller-Gatermann, A. Goasduff, A. Gadea, P.R. John, D. Kocheva, T. Konstantinopoulos, A. Korichi, A. Kusoglu, S.M. Lenzi, S. Leoni, R. Lozeva, A. Maj, R. Perez, N. Pietralla, C. Shand, O. Stezowski, D. Wilmsen, D. Yordanov, D. Barrientos, P. Bednarczyk, B. Birkenbach, A.J. Boston, H.C. Boston, I. Burrows, B. Cederwall, M. Ciemala, J. Collado, F. Crespi, D. Cullen, H.J. Eberth, J. Goupil, L. Harkness, H. Hess, A. Jungclaus, W. Korten, M. Labiche, R. Menegazzo, D. Mengoni, B. Million, J. Nyberg, Zs. Podolyák, A. Pullia, B. Quintana Arnés, F. Recchia, P. Reiter, F. Saillant, M.D. Salsac, E. Sanchis, C. Theisen, J.J. Valiente Dobon, and O. Wieland

Subjects
Physics, QC1-999
Abstract

A lifetime measurement of the 19/2− state in 207Pb 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 208Pb beam impinging on a 100Mo 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 207Pb. An analysis in terms of a particle-octupole-vibration coupling model indicates that the measured B(E3) value in 207Pb 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. Keywords: AGATA spectrometer, γ-Ray tracking, VAMOS++ spectrometer, Plunger device, Nuclear deformation, Octupole phonon

Published
2019
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29. Pygmy dipole resonance in 124Sn populated by inelastic scattering of 17O

Author

L. Pellegri, A. Bracco, F.C.L. Crespi, S. Leoni, F. Camera, E.G. Lanza, M. Kmiecik, A. Maj, R. Avigo, G. Benzoni, N. Blasi, C. Boiano, S. Bottoni, S. Brambilla, S. Ceruti, A. Giaz, B. Million, A.I. Morales, R. Nicolini, V. Vandone, O. Wieland, D. Bazzacco, P. Bednarczyk, M. Bellato, B. Birkenbach, D. Bortolato, B. Cederwall, L. Charles, M. Ciemala, G. De Angelis, P. Désesquelles, J. Eberth, E. Farnea, A. Gadea, R. Gernhäuser, A. Görgen, A. Gottardo, J. Grebosz, H. Hess, R. Isocrate, J. Jolie, D. Judson, A. Jungclaus, N. Karkour, M. Krzysiek, E. Litvinova, S. Lunardi, K. Mazurek, D. Mengoni, C. Michelagnoli, R. Menegazzo, P. Molini, D.R. Napoli, A. Pullia, B. Quintana, F. Recchia, P. Reiter, M.D. Salsac, B. Siebeck, S. Siem, J. Simpson, P.-A. Söderström, O. Stezowski, Ch. Theisen, C. Ur, J.J. Valiente Dobon, and M. Zieblinski

Subjects
Physics, QC1-999
Abstract

The γ decay from the high-lying states of 124Sn was measured using the inelastic scattering of 17O at 340 MeV. The emitted γ rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented ΔE–E silicon telescopes. The angular distribution was measured both for the γ rays and the scattered 17O ions. An accumulation of E1 strength below the particle threshold was found and compared with previous data obtained with (γ,γ′) and (α,α′γ) reactions. The present results of elastic scattering, and excitation of E2 and E1 states were analysed using the DWBA approach. From this comprehensive description the isoscalar component of the 1− excited states was extracted. The obtained values are based on the comparison of the data with DWBA calculations including a form factor deduced using a microscopic transition density. Keywords: Low-lying electric dipole excitations, 124Sn, Isospin character

Published
2014
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30. Kaon Tagging at 0° Scattering Angle for High-Resolution Decay-Pion Spectroscopy

Author

Patrick Achenbach, Joerg Reinhold, Osamu Hashimoto, Salvador Sánchez Majos, Liguang Tang, B. S. Schlimme, O. Borodina, Concettina Sfienti, V. Bozkurt, Sho Nagao, R. Böhm, T. R. Saito, Simon Širca, Alicia Sanchez Lorente, F. Schulz, Junichiro Kusaka, Naoki Arai, U. Müller, Josef Pochodzalla, Kazushige Maeda, Kyo Tsukada, Carlos Ayerbe Gayoso, L. Debenjak, Anselm Esser, Y. Fujii, Amur Margaryan, Toshiyuki Gogami, E. Kim, Mar Gómez Rodríguez, Masashi Kaneta, Damir Bosnar, C. Rappold, M. Schoth, Hiroki Kanda, Satoshi Nakamura, M. O. Distler, Michaela Thiel, Harald Merkel, S. Hirose, Ivica Friščić, and S. Lunardi, P.G. Bizzeti, Sonia Kabana, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini and J.J. Valiente‐Dobon

Subjects
Physics, Particle physics, Spectrometer, Scattering, QC1-999, Nuclear Theory, Bremsstrahlung, Strangeness production, Nuclear physics, Momentum, Pion, Pair production, Electron Scattering, Hypernuclei, MAMI, KAOS, Decay-Pion Spectroscopy, High Energy Physics::Experiment, Nuclear Experiment, Microtron
Abstract

At the Mainz Microtron hypernuclei can be studied by (e,e'K) reactions. By detecting the kaon which is emitted in forward direction, with the KAOS spectrometer placed at 0 scattering angle, reactions involving open strangeness production are tagged. High-resolution magnetic spectrometers are then used to coincidentally detect the mono- energetic decay-pions from mesonic two-body weak decays of light hypernuclei at rest. As a pioneering experiment has confirmed, the KAOS spectrometer is exposed to a large flux of background particles, mostly positrons from bremsstrahlung pair production. In order to increase the e ciency of kaon identification the KAOS spectrometer was modi- fied to suppress background particles at the cost of a high momentum resolution, which is less important for this experiment. This was achieved by placing up to 14 cm of lead absorbers in front of the detectors, in which positrons are blocked by forming electro- magnetic showers while the e ect on kaons is limited. An additional time-of-flight wall and a new threshold ˘ Cerenkov detector help to increase the detection e ciency of kaons.

Published
2014

31. Transfer reactions on light exotic nuclei studied with CHIMERA detector at LNS

Author

G. Cardella, L. Acosta, F. Amorini, L. Auditore, I. Berceanu, M. Buscemi, M. B. Chatterjiee, E. DeFilippo, L. Francalanza, R. Gianì, L. Grassi, E. La Guidara, G. Lanzalone, D. Loria, T. Minniti, A. Pagano, E. V. Pagano, M. Papa, S. Pirrone, G. Politi, A. Pop, F. Porto, F. Rizzo, P. Russotto, S. Santoro, A. Trifiró, M. Trimarchi, G. Verde, LOMBARDO, IVANO, ROSATO, ELIO, VIGILANTE, MARIANO, S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, G., Cardella, L., Acosta, F., Amorini, L., Auditore, I., Berceanu, M., Buscemi, M. B., Chatterjiee, E., Defilippo, L., Francalanza, R., Gianì, L., Grassi, E., La Guidara, G., Lanzalone, Lombardo, Ivano, D., Loria, T., Minniti, A., Pagano, E. V., Pagano, M., Papa, S., Pirrone, G., Politi, A., Pop, F., Porto, F., Rizzo, Rosato, Elio, P., Russotto, S., Santoro, A., Trifiró, M., Trimarchi, G., Verde, Vigilante, Mariano, Cardella, G., Acosta, L., Amorini, F., Auditore, L., Berceanu, I., Chatterjiee, M., Defilippo, E., Francalanza, L., Gianì, R., Grassi, L., La Guidara, E., Lanzalone, G., Lombardo, I., Loria, D., Minniti, T., Pagano, A., Pagano, E., Papa, M., Pirrone, S., Politi, G., Pop, A., Porto, F., Rizzo, F., Rosato, E., Russotto, P., Santoro, S., Trifirò, A., Trimarchi, M., Verde, G., and Vigilante, M.

Subjects
Physics, Elastic scattering, education.field_of_study, QC1-999, Population, Resolution (electron density), Nuclear reaction, Coincidence, Spectral line, Physics and Astronomy (all), Transfer reactions, Excited state, Center of mass, Atomic physics, education, Beam (structure)
Abstract

The kinematical coincidence method is used to extract angular distribution of elastic scattering and transfer reactions. The detected light particle energy spectra are used to extract the angular distribution with around 1° resolution in the Center of Mass (CM) system. Examples with 10Be beam are presented. In the case of proton scattering, γ-ray coincidences are used to discriminate excited levels population from elastic scattering. © Owned by the authors, published by EDP Sciences, 2014.

Published
2014

32. ASY-EOS experiment at GSI: investigating the symmetry enenrgy at supra-satutation densities

Author

P. Russotto, M. Chartier, M. D. Cozma, E. De Filippo, A. Le Fevre, S. Gannon, A. Gašsparić, M. Kiš, S. Kupny, Y. Leifels, R. Lemmon, Q. Li, J. Lukasik, P. Marini, P. Pawlowski, S. Santoro, W. Trautmann, M. Veselsky, L. Acosta, M. Adamczyk, A. Al Ajlan, M. Al Garawi, S. Al Homaidhi, F. Amorini, L. Auditore, T. Aumann, Y. Ayyad, V. Baran, Z. Basrak, R. Bassini, J. Benlliure, C. Boiano, C. Boisjoli, K. Boretzky, J. Brzychczyk, A. Budzanowski, G. Cardella, P. Cammarata, Z. Chajecki, A. Chbihi, M. Colonna, B. Czech, M. Di Toro, M. Famiano, V. Greco, L. Grassi, C. Guazzoni, P. Guazzoni, M. Heil, L. Heilborn, R. Introzzi, T. Isobe, K. Kezzar, A. Krasznahorskay, N. Kurz, E. La Guidara, G. Lanzalone, P. Lasko, W. G. Lynch, Z. Matthews, L. May, T. Minniti, M. Mostazo, A. Pagano, M. Papa, S. Pirrone, R. Pleskac, G. Politi, F. Porto, R. Reifarth, W. Reisdorf, F. Riccio, F. Rizzo, D. Rossi, H. Simon, I. Skwirczynska, Z. Sosin, L. Stuhl, A. Trifirò, M. Trimarchi, M. B. Tsang, G. Verde, A. Wieloch, P. Wigg, H. H. Wolter, P. Wu, S. Yennello, P. Zambon, L. Zetta, M. Zoric, LOMBARDO, IVANO, ROSATO, ELIO, VIGILANTE, MARIANO, S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, P., Russotto, M., Chartier, M. D., Cozma, E., De Filippo, A., Le Fevre, S., Gannon, A., Gašsparić, M., Kiš, S., Kupny, Y., Leifel, R., Lemmon, Q., Li, J., Lukasik, P., Marini, P., Pawlowski, S., Santoro, W., Trautmann, M., Veselsky, L., Acosta, M., Adamczyk, A., Al Ajlan, M., Al Garawi, S., Al Homaidhi, F., Amorini, L., Auditore, T., Aumann, Y., Ayyad, V., Baran, Z., Basrak, R., Bassini, J., Benlliure, C., Boiano, C., Boisjoli, K., Boretzky, J., Brzychczyk, A., Budzanowski, G., Cardella, P., Cammarata, Z., Chajecki, A., Chbihi, M., Colonna, B., Czech, M., Di Toro, M., Famiano, V., Greco, L., Grassi, C., Guazzoni, P., Guazzoni, M., Heil, L., Heilborn, R., Introzzi, T., Isobe, K., Kezzar, A., Krasznahorskay, N., Kurz, E., La Guidara, G., Lanzalone, P., Lasko, Lombardo, Ivano, W. G., Lynch, Z., Matthew, L., May, T., Minniti, M., Mostazo, A., Pagano, M., Papa, S., Pirrone, R., Pleskac, G., Politi, F., Porto, R., Reifarth, W., Reisdorf, F., Riccio, F., Rizzo, Rosato, Elio, D., Rossi, H., Simon, I., Skwirczynska, Z., Sosin, L., Stuhl, A., Trifirò, M., Trimarchi, M. B., Tsang, G., Verde, Vigilante, Mariano, A., Wieloch, P., Wigg, H. H., Wolter, P., Wu, S., Yennello, P., Zambon, L., Zetta, and M., Zoric

Subjects
flow, NUCLEAR COLLISIONS
Abstract

The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy-ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. The results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model simulations favoured a moderately soft symmetry term, but suffer from a considerable statistical uncertainty. These results have been confirmed by an independent analysis based on the Tübingen QMD simulations. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration. The present status of the data analysis is reported

Published
2014

33. Probing the symmetry energy at low density using observables from neck fragmentation

Author

G. Cardella, Lucrezia Auditore, M. Trimarchi, Michele Papa, R. Planeta, A. Trifirò, A. Grzeszczuk, L. Zetta, Maria Colonna, E. La Guidara, Mariano Vigilante, G. Politi, F. Porto, Giuseppe Verde, F. Rizzo, L. Acosta, S. Pirrone, C. Maiolino, K. Siwek-Wilczyńska, E. V. Pagano, I. Skwira-Chalot, F. Amorini, Ji-Youn Han, C. Agodi, J. Wilczyński, E. Piasecki, Triestino Minniti, G. Lanzalone, A. Pagano, P. Guazzoni, R. Gianì, I. Berceanu, E. Geraci, Ivano Lombardo, Amalia Pop, V. Baran, T. Cap, L. Quattrocchi, L. Grassi, P. Russotto, Elio Rosato, E. De Filippo, L. Francalanza, S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, E., Defilippo, L., Acosta, C., Agodi, F., Amorini, A., Anzalone, L., Auditore, V. Baran I., Berceanu, T., Cap, G., Cardella, M., Colonna, L., Francalanza, E., Geraci, R., Gianì, L., Grassi, A., Grzeszcuk, P., Guazzoni, J., Han, E., La Guidara, G., Lanzalone, Lombardo, Ivano, C., Maiolino, T., Minniti, A., Pagano, E. V., Pagano, M., Papa, E., Piasecki, R., Planeta, S., Pirrone, G., Politi, A., Pop, F., Porto, L., Quattrocchi, F., Rizzo, Rosato, Elio, P., Russotto, K., Siwek Wilczynska, I., Skwira Chalot, A., Trifiró, M., Trimarchi, G., Verde, Vigilante, Mariano, J., Wilczynski, and L., Zetta

Subjects
Physics, Projectile, QC1-999, Observable, ionic collisions, isospin-dependent quantum, Fragmentation (mass spectrometry), fragmentation, fragments, Low density, Incident energy, NUCLEAR COLLISIONS, Atomic physics, Nuclear Experiment
Abstract

Semi-peripheral collisions of ^{64}Ni + ^{124}Sn in direct and inverse kinematics, at 35 A MeV incident energy, are studied to characterize the dynamical origin and align-ments properties of fragments emission at midrapidity. This emission is partly due to the fragmentation of a transient neck joining the projectile and target in the early stages of the reaction. Recently we exploited observable from neck fragmentation to constraint the density dependence of the symmetry energy. In this contribution we focus on the density evolution of the mid-rapidity source. An experimental survey is suggested to check if data are consistent with the formation of neck fragments in a dilute density region in contact with the projectile-like and target-like spectators at normal saturation density.

Published
2014

34. The european FAZIA initiative: a high-performance digital telescope array for heavy-ion studies

Author

Giovanni Casini, N. Le Neindre, Paola Marini, Gabriele Pasquali, G. Pastore, A. Ordine, D. Gruyer, J.D. Frankland, B. Borderie, E. Bonnet, Maurizio Bini, Silvia Piantelli, E. Vient, R. Bougault, F. Salomon, S. Carboni, M. F. Rivet, M. Guerzoni, Tommaso Marchi, Elio Rosato, Sandro Barlini, Luca Morelli, Mariano Vigilante, Giacomo Poggi, A. Chbihi, M. Bruno, A. Kordjasz, Andrea Stefanini, O. Lopez, Alessandro Olmi, M. Pârlog, M. Degerlier, T. Twaróg, M. Cinausero, G. Spadaccini, Simone Valdré, T. Kozik, P. Edelbruck, F. Gramegna, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze (INFN, Sezione di Firenze), Istituto Nazionale di Fisica Nucleare (INFN), 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), 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), Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (INFN, Sezione di Napoli), FAZIA, 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 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, G., Casini, S., Barlini, G., Pasquali, G., Pastore, M., Bini, S., Carboni, A., Olmi, S., Piantelli, G., Poggi, A. A., Stefanini, S., Valdré, E., Bonnet, B., Borderie, R., Bougault, M., Bruno, A., Chbihi, M., Cinausero, M., Degerlier, P., Edelbruck, J. D., Frankland, F., Gramegna, D., Gruyer, M., Guerzoni, A., Kordyasz, T., Kozik, N., Le Neindre, O., Lopez, T., Marchi, P., Marini, L., Morelli, Ordine, Antonio, M., Parlog, M. F., Rivet, Rosato, Elio, F., Salomon, Spadaccini, Giulio, T., Twarog, E., Vient, and Vigilante, Mariano

Subjects
Charged Particle Detector, Physics - Instrumentation and Detectors, Preamplifier, Computer science, QC1-999, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, law.invention, Telescope, pulse shape discrimination, law, 0103 physical sciences, Electronics, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Aerospace engineering, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, 010308 nuclear & particles physics, business.industry, Physics, Instrumentation and Detectors (physics.ins-det), Modular design, Identification (information), isotopic identification, Pulse shape analysis, Heavy ion, business, New Facilities and Instrumentation, Product identification
Abstract

The european Fazia collaboration aims at building a new modular array for charged product identification to be employed for heavy-ion studies. The elementary module of the array is a Silicon-Silicon-CsI telescope, optimized for ion identification also via pulse shape analysis. The achievement of top performances imposes specific electronics which has been developed by FAZIA and features high quality charge and current preamplifiers, coupled to fully digital front-end. During the initial R&D phase, original and novel solutions have been tested in prototypes, obtaining unprecedented ion identification capabilities. FAZIA is now constructing a demonstrator array consisting of about two hundreds telescopes arranged in a compact and transportable configuration. In this contribution, we mainly summarize some aspects studied by FAZIA to improve the ion identification. Then we will briefly discuss the FAZIA program centered on experiments to be done with the demonstrator. First results on the isospin dynamics obtained with a reduced set-up demonstrate well the performance of the telescope and represent a good starting point towards future investigations with both stable and exotic beams., 8 pages, 2 figures, Contribution to conference proceedings of the 25th International Nuclear Physics Conference (INPC 2013) Journal-ref: 25th International Nuclear Physics Conference (INPC 2013), Firenze : Italy (2013)

Published
2013
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35. Isospin transport in 84Kr+112,124Sn reactions at Fermi energies

Author

M. Cinausero, M.F. Rivet, N. Le Neindre, R. Bougault, T. Marchi, R. Alba, Sandro Barlini, Gabriele Pasquali, T. Twaróg, D. Gruyer, G. Spadaccini, O. Lopez, Elio Rosato, B. Borderie, Giovanni Casini, E. Bonnet, J.D. Frankland, Tomasz Kozik, Maurizio Bini, Silvia Piantelli, Alessandro Olmi, Luca Morelli, M. Parlog, A. Chbihi, Giacomo Poggi, E. Vient, C. Maiolino, Andrea Stefanini, F. Gramegna, M. Bruno, S. Carboni, P. R. Maurenzig, M. Degerlier, Mariano Vigilante, Domenico Santonocito, 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), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire 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), FAZIA, Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, S., Piantelli, G., Casini, A., Olmi, S., Barlini, M., Bini, S., Carboni, P. R., Maurenzig, G., Pasquali, G., Poggi, A. A., Stefanini, R., Bougault, N., Le Neindre, O., Lopez, M., Pârlog, E., Vient, E., Bonnet, A., Chbihi, J. D., Frankland, D., Gruyer, Rosato, Elio, Spadaccini, Giulio, Vigilante, Mariano, B., Borderie, M. F., Rivet, M., Bruno, L., Morelli, M., Cinausero, M., Degerlier, F., Gramegna, T., Marchi, R., Alba, C., Maiolino, D. Santonocito T., Kozik, and T., Twaróg

Subjects
Nuclear reaction, Physics, Density gradient, QC1-999, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nuclear reaction, Ion, isotopic identification, Diffusion process, Isospin, Nuclear reactions, Nuclear Experiment (nucl-ex), Atomic physics, Nuclear Experiment, Transport phenomena, Beam (structure), Nuclear Physics, Fermi Gamma-ray Space Telescope
Abstract

Isospin transport phenomena in dissipative heavy ion collisions have been investigated at Fermi energies with a beam of 84Kr at 35AMeV. A comparison of the /Z of light and medium products forward-emitted in the centre of mass frame when the beam impinges on a n-poor 112Sn and a n-rich 124Sn targets is presented. Data were collected by means of a three-layer telescope with very good performances in terms of mass identification (full isotopic resolution up to Z about 20 for ions punching through the first detector layer) built by the FAZIA Collaboration and located just beyond the grazing angle for both reactions. The /Z of the decay products emitted when the n-rich target is used is always higher than that associated to the n-poor one. Since the detector was able to measure only fragments coming from the QuasiProjectile decay and/or neck emission, the observed behaviour can be ascribed to the isospin diffusion, driven by the isospin gradient between QuasiProjectile and QuasiTarget. Moreover, for light fragments the /Z as a function of the lab velocity of the fragment increases when we move from the QuasiProjectile velocity to the centre of mass (neck zone). This effect can be interpreted as an evidence of isospin drift driven by the density gradient between the QuasiProjectile zone (at normal density) and the more diluted neck zone., Comment: 4 pages, 3 figures, Contribution to conference proceedings of the 25th International Nuclear Physics Conference (INPC 2013) Journal-ref: 25th International Nuclear Physics Conference (INPC 2013), Firenze : Italy (2013)

Published
2013
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36. Decay competition for IMF produced in the collisions 78Kr+40Ca and 86Kr+48Ca at 10 A*MeV

Author

G. Cardella, Maria Colonna, D. Loria, Giuseppe Verde, S. Pirrone, F. Porto, M. La Commara, W. U. Schroeder, G. Ademard, Jan Toke, Elio Rosato, E. Geraci, J.P. Wieleczko, E. La Guidara, I. Berceanu, C. Beck, G. Spadaccini, E. De Filippo, E. Henry, F. Amorini, Eric Bonnet, A. Chbihi, Michele Papa, A. Pagano, Mariano Vigilante, M.F. Rivet, M. Quinlann, Antonio Trifiro, G. Lanzalone, Ivano Lombardo, P. Lautesse, M. Trimarchi, K. Mazurek, N. Le Neindre, Lucrezia Auditore, J.D. Frankland, D. Lebhertz, G. Politi, P. Russotto, F. Rizzo, E. Piasecki, B. Borderie, 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), 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), 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), 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 Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, LA COMMARA, Marco, S., Pirrone, G., Politi, J. P., Wieleczko, G., Ademard, E., De Filippo, Vigilante, Mariano, F., Amorini, L., Auditore, C., Beck, I., Berceanu, E., Bonnet, B., Borderie, G., Cardella, A., Chbihi, M., Colonna, J. D., Frankland, E., Geraci, E., Henry, E., La Guidara, G., Lanzalone, P., Lautesse, D., Lebhertz, N., Le Neindre, Lombardo, Ivano, D., Loria, K., Mazurek, A., Pagano, M., Papa, E., Piasecki, F., Porto, M., Quinlann, F., Rizzo, Rosato, Elio, P., Russotto, W. U., Schroeder, Spadaccini, Giulio, A., Trifirò, J., Tõke, M., Trimarchi, G., Verde, 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
Nuclear reaction, Physics, Fusion, 010308 nuclear & particles physics, QC1-999, compound nucleu, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Excited state, Isospin, 0103 physical sciences, fragments, Nuclear reactions, Atomic physics, 010306 general physics
Abstract

Expérience GANIL; International audience; Decay modes of excited compound systems 118Ba and 134Ba, produced respectively in the 78Kr+40Ca and 86Kr+48Ca collisions at 10 A*MeV, are investigated. In particular, the competition between the various disintegration path of medium mass compound nuclei, formed by fusion processes, the production of the so referred Intermediate Mass Fragments (IMF), and the isospin dependence of the decay process are studied. Data were taken at the INFN-Laboratori Nazionali del Sud (LNS) by using the CHIMERA array. Data analysis is in progress; a first indication on the average-energy angular distributions suggests pre-equilibrium effects affecting the data and the presence of isotopical effects.

Published
2013
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