Nuclear Structure Problems - Proceedings Of The French-japanese Symposium

Hideaki Otsu, Tohru Motobayashi, Patricia Roussel-Chomaz, Takaharu Otsuka

• Publisher: WSPC
• Year: 2012
• Print ISBN: 9789814417945
• eBook ISBN: 9789814417969
• Topic: Sciences biologiques
• Subtopic: Science générale

The book contains the papers presented in the French–Japan Symposium on Nuclear Structure Problems, held in January 2011 at RIKEN Wako Campus with 100 participants.

Based on the long history of collaboration between France and Japan in the field of nuclear physics, various problems in recent and future studies are discussed. Emphasis is on the structure of nuclei far from the stability, reactions involving stable and unstable nuclei, nuclear processes and properties of astrophysical interest, synthesis of super-heavy elements, and instrumentation and accelerator projects.

Contents:

• GANIL-SPIRAL2: A New ERA (S Gales)
• Nuclear Physics in Japan and RIKEN Nishina Center (H En'yo)
• Nuclear Physics Programs at RIBF (H Sakurai)
• Unbound States of the Drip-Line Nucleus 24 O (V Lapoux, S Boissinot, E C Pollacco, F Flavigny, C Louchart, L Nalpas, A Obertelli, H Otsu, H Baba, R J Chen, N Fukuda, N Inabe, D Kameda, M Matsushita, T Motobayashi, T Onishi, E Y Nikolskii, M Nishimura, H Sakurai, M Takechi, S Takeuchi, Y Togano, K Yoneda, A Yoshida, K Yoshida, A Matta, Y Blumenfeld, S Franchoo, F Hammache, Ph Rosier, E Rindel, P Gangnant, Ch Houarner, J F Libin and F Saillant)
• High-Resolution Ion-Optical Analysis of RI-Beams with the Sharaq Spectrometer (T Uesaka, S Michimasa, H Tokieda, S Shimoura, S Ota, Y Sasamoto, H Miya, S Kawase, Y Kikuchi, K Kisamori, M Takaki, H Matsubara, M Dozono, S Noji, K Miki, K Yako, H Sakai, H Takeda, D Kameda, T Ohnishi, Y Yanagisawa, T Kubo, H Baba, T Kawabata, P Roussel-Chomaz, M Sasano and G P A Berg)
• Nuclear Moments of μ-Second Isomeric Fragments at BigRIPS (R Chevrier, J M Daugas, L Gaudefroy, M Hass, H Haas, H Ueno, N Aoi, N Fukuda, Y Ichikawa, N Inabe, M Ishihara, D Kameda, T Kubo, T Ohnishi, H Takeda, H Watanabe, A Yoshimi, K Asahi, T Furukawa, H Hayashi, H Iijima, T Inoue, Y Ishii, T Nanao, K Suzuki, M Tsuchiya, D L Balabanski, G Georgiev, S Cootenier, G Neyens and M Rajabali)
• Production of Spin-Aligned RI Beams via the Two-Step Fragmentation Reaction (H Ueno, Y Ichikawa, Y Ishii, T Furukawa, A Yoshimi, D Kameda, H Watanabe, N Aoi, K Asahi, D L Balabanski, R Chevrier, J M Daugas, N Fukuda, G Georgiev, H Hayashi, H Iijima, N Inabe, T Inoue, M Ishihara, T Kubo, T Nanao, T Ohnishi, K Suzuki, M Tsuchiya, H Takeda and M M Rajabali)
• Recent Studies of Transfer Reactions with MUST2 at GANIL and RIKEN (D Beaumel)
• Lifetime Measurement of 2 + 1 State in 74 Zn by Recoil-Distance Doppler-Shift Method (M Niikura, B Mouginot, F Azaiez, S Franchoo, I Matea, I Stefan, D Verney, M Assie, P Bednarczyk, C Borcea, A Burger, G Burgunder, A Buta, L Càceres, E Cléement, L Coquard, G de Angelis, G de France, F de Oliveira Santos, A Dewald, A Dijon, Z Dombradi, E Fiori, C Fransen, G Friessner, L Gaudefroy, G Georgiev, S Grévy, M Hackstein, M N Harakeh, F Ibrahim, O Kamalou, M Kmiecik, R Lozeva, A Maj, C Mihai, O Möller, S Myalski, F Negoita, D Pantelica, L Perrot, Th Pissula, F Rotaru, W Rother, J A Scarpaci, C Stodel, J C Thomas and P Ujic)
• Recent Progress of Nuclear Density Functional Calculations: Toward to Next-Generation Supercomputer (T Inakura)
• Tensor Correlations on Spin-Orbit Splittings and Spin Dependent Excitations (H Sagawa, L-G Cao, C L Bai and G Colò)
• Systematic Study of Many-Particle and Many-Hole States in and Around the “Island of Inversion” (M Kimura)
• Coexistence of Various Deformed States and α Clustering in 42 Ca (Y Taniguchi)
• Tops-on-Top Model for Triaxial Strongly Deformed Bands in Even-A Nuclei (K Sugawara-Tanabe and K Tanabe)
• Structure Beyond the Neutron Drip-Line: 9 He (T Al Kalanee, J Gibelin, P Roussel-Chomaz, D Beaumel, Y Blumenfeld, B Fernandez-Dominguez, C Force, L Gaudefroy, A Gillibert, J Guillot, H Iwasaki, N Keeley, S Krupko, V Lapoux, W Mittig, X Mougeot, L Nalpas, N A Orr, E Pollacco, K Rusek, T Roger, H Savajols, N de Séréville, S Sidorchuk, D Suzuki and I Strojek)
• Tensor Correlation in Light Nuclei Studied with Tensor Optimized Shell Model (T Myo, A Umeya, H Toki and K Ikeda)
• Symmetry Energy, Pairing Correlations in Nuclear Matter and Giant Resonances in Tin Isotopes (M-K Cheoun, E Ha and C Y Ryu)
• Systematic Study of E 1 Mode Using Canonical-Basis TDHFB (S Ebata, T Nakatsukasa, T Inakura, K Yoshida, Y Hashimoto and K Yabana)
• Studies of Light Neutron-Excess Nuclei from Bounds to Continuum (M Ito)
• Triaxial Nuclear Molecule 28 Si – 28 Si in Resonances (E Uegaki and Y Abe)
• Black-Sphere Approximation to Nuclei and Its Application to Reactions with Neutron-Rich Nuclei (A Kohama, K Iida and K Oyamatsu)
• Beyond-Mean-Field Models for Correlated Nucleons. Applications of Second Random-Phase Approximation to 16 O and 48 Ca (M Grasso, D Gambacurta and F Catara)
• Derivation of the Interacting Boson Model from Mean-Field Theory (K Nomura)
• Large-Amplitude Quadrupole Collective Dynamics in Neutron-Rich Mg and Cr Isotopes (N Hiniohara, K Sato, K Yoshida, T Nakatsukasa, M Matsuo and K Matsuyanagi)
• Microscopic Description of Large-Amplitude Collective Motions with Local QRPA Inertial Masses (K Sato, N Hinohara, T Nakatsukasa, M Matsuo and K Matsuyanagi)
• Two-Proton Radioactivity as a Tool for Nuclear Structure (B Blank, P Ascher, L Audirac, J Giovinazzo, N Adimi, G Canchel, F Delalee, C E Demonchy, C Dossat, S Grévy, L Hay, J Huikari, T Kurtukian-Nieto, S Leblanc, I Matea, J-L Pedroza, J Pibernat, L Serani, F de Oliveira Santos, L Perrot, P C Srivastava, C Stodel, J-C Thomas, C Borcea, I Companis, B A Brown and L V Grigorenko)
• 14 Be( P,N ) 13 B Reaction at 69 MeV and Proportionality Relationship Between Forward Angle ( P,N ) Cross Section and B(GT) (Y Satou, T Nakamura, Y Kondo, N Matsui, Y Hashimoto, T Nakabayashi, T Okumura, M Shinohara, N Fukuda, T Sugimoto, H Otsu, Y Togano, T Motobayashi, H Sakurai, Y Yanagisawa, N Aoi, S Takeuchi, T Gomi, M Ishihara, S Kawai, H J Ong, T K Onishi, S Shimoura, M Tamaki, T Kobayashi, Y Matsuda, N Endo and M Kitayama)
• Exploring Mg Isotope Structures through Beta-Delayed Decay of Spin-Polarized Na Isotopes (T Shimoda, K Tajiri, K Kura, A Odahara, T Hori, M Kazato, T Masue, M Suga, A Takashima, T Suzuki, T Fukuchi, Y Hirayama, N Imai, H Miyatake, M Pearson, C D P Levy and K P Jackson)
• A New Method to Explore High-Spin States by RI Beam Induced Fusion Reaction (A Odahara, T Shimoda, Y Ito, H Nishibata, K Tajiri, J Takatsu, N Hamatani, R Yokoyama, C Petrache, R Leguillon, T Suzuki, E Ideguchi, H Watanabe, Y Wakabayashi, K Yoshinaga, D Beaumel, P Desesquelles, D Curien, D Guinet and G Lehaut)
• The Super-Allowed Fermi Type Charge Exchange Reaction for Studies of Isovector Non-Spin-Flip Monopole Resonance (Y Sasamoto, T Uesaka, S Shimoura, S Michimasa, S Ota, H Tokieda, H Miya, S Kawase, Y Kikuchi, K Kisamori, M Takaki, M Dozono, H Mathubara, K Yako, S Noji, K Miki, H Sakai, T Kubo, Y Yanagisawa, H Takeda, K Yoshida, T Ohnishi, N Fukuda, D Kameda, N Inabe, N Aoi, S Takeuchi, T Ichihara, H Baba, S Sakaguchi, P Doornenbal, H Wang, R Chen, Y Shimizu, T Kawahara, T Kawabata, N Yokota, Y Maeda, H Miyasako and G P A Berg)
• Invariant-Mass Spectroscopy of the Unbound Nucleus 13 Be (Y Kondo, T Nakamura, Y Satou, Y Hashimoto, N Matsui, T Nakabayashi, T Okumura, M Shinohara, T Matsumoto, N Aoi, N Fukuda, T Gomi, M Ishihara, H Otsu, H Sakurai, T Sugimoto, S Takeuchi, Y Yanagisawa, N Endo, M Kitayama, T Kobayashi, Y Matsuda, S Kawai, Y Togano, H J Ong, T K Onishi, K Ogata, S Shimoura and M Tamaki)
• Gamow-Teller Transitions in Proton Rich Nuclei Deduced from the Combined Study of β-Decay and Charge-Exchange Reactions (Y Fujita, B Rubio, B Blank, W Gelletly, T Adachi, J Agramunt, A Algora, P Ascher, B Bilgier, L Cáceres, R B Cakirli, E Ganioğlu, M Gerbaux, J Giovinazzo, S Grévy, H Fujita, O Kamalou, H C Kozer, L Kucuk, T Kurtukian-Nieto, F Molina, S E A Orrigo, L Popescu, A M Rogers, G Susoy, C Stodel, T Suzuki, A Tamii and J-C Thomas)
• Supernova Nucleosynthesis, Neutrino Mass and Oscillation, and Nuclear Weak Interactions (T Kajino, K Nakamura, K Sato, K Shaku, T Yoshida, T Hayakawa, S Chiba, D Yamazaki, M-K Cheoun and G J Mathews)
• KEK Isotope Separation System for β Decay Spectroscopy of R-Process Nuclei (Y X Watanabe, H Miyatake, S C Jeong, H Ishiyama, N Imai, Y Hirayama, M Oyaizu, K Niki, M Okada, M Wada and T Sonoda)
• Spin Modes in Nuclei and Applications to Astrophysical Processes (T Suzuki)
• Proton-Capture Nucleosynthesis in Neutrino-Driven Supernova Explosions (S Wanajo, H-T Janka and S Kubono)
• Momentum-Dependent Spin-Current Tensor Contribution in Collision Dynamics (Y Iwata)
• Strong Nuclear Couplings as a Source of Coulomb Rainbow and Near Barrier Fusion Suppression (N Alamanos and N Keeley)
• Analytic Study of the Hindered Fusion A La Recherche D'une Formule Analytique Pour La Fusion Entravee (Y Abe, C Shen, D Boilley and B B Giraud)
• Studies of Fission-Yield Models (P Möller and J Randrup)
• Digital Electronics for γ-Ray Spectroscopy — The Path to Low Cross-Sections: First Evidence of a Rotational Band in 246 Fm (J Piot for the JR83 Experiment Collaborators)
• MINOS: A Vertex Tracker for In-Beam γ Spectroscopy at Relativistic Energies (A Obertelli on behalf of the MINOS Collaboration)
• Elastic Scattering of Protons with Radioactive Ion Beams: Overview of ESPRI Project (J Zenihiro, Y Matsuda, H Sakaguchi, S Terashima, H Otsu, H Takeda, K Ozeki, K Yoneda, K Tanaka, T Ohnishi, T Kobayashi, T Murakami, Y Maeda, Y Sato, I Tanihata, O H Jing, M Takechi and M Kanazawa)

Lifetime measurement of 2⁺₁ state in ⁷⁴Zn by recoil-distance
Doppler-shift method

M. Niikura*¹, B. Mouginot*¹, F. Azaiez*¹, S. Franchoo*¹, I. Matea*¹, I. Stefan*¹,

D. Verney*¹, M. Assie*^1,2, P. Bednarczyk*³, C. Borcea*⁴, A. Burger*⁵,

G. Burgunder*², A. Buta*⁴, L. Cáceres*², E. Cléement*², L. Coquard*⁶,

G. de Angelis*⁷, G. de France*², F. de Oliveira Santos*², A. Dewald*⁸, A. Dijon*²,

Z. Dombradi*⁹, E. Fiori*¹⁰, C. Fransen*⁸, G. Friessner*⁸, L. Gaudefroy*¹¹,

G. Georgiev*¹⁰, S. Grévy*², M. Hackstein*⁸, M. N. Harakeh*^2,12, F. Ibrahim*¹,

O. Kamalou*², M. Kmiecik*³, R. Lozeva*¹⁰, A. Maj*³, C. Mihai*⁴, O. Möiler*⁶,

S. Myalski*³, F. Negoita*⁴, D. Pantelica*⁴, L. Perrot*¹, Th. Pissulla*⁸, F. Rotaru*⁴,

W. Rother*⁸, J. A. Scarpaci*¹, C. Stodel*², J. C. Thomas*², and P. Ujic*²

*¹ IPN Orsay, CNRS/IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex, France

*² GANIL, CEA/CSM-CNRS/IN2P3, F-14076 Caen Cedex 05, France

*³ IFJ PAN, PL-31342 Kraków, Poland

*⁴ IFIN-HH, ROM-76900 Bucharest-Magurele, Romania

*⁵ Department of Physics, University of Oslo, N-0315 Oslo, Norway

*⁶ Institut für Kernphysik, der Technische Universität Darmstadt, D-64289 Darmstadt, Germany

*⁷ Laboratori Nazionali di Legnaro, INFN, I-35020 Legnaro, Padova, Italy

*⁸ Institut für Kernphysik, Universität zu Köln, D-50937 Klön, Germany

*⁹ ATOMKI, H-4001 Debrecen, Hungary

*¹⁰ CSNSM, IN2P3-CNRS, Université Paris-Sud 11, F-91405 Orsay, France

*¹¹ CEA, DAM, DIF, F-91297 Arpajon, France

*¹² KVI, University of Groningen, NL-9747 AA Groningen, The Netherlands

We have performed the first direct lifetime measurement of the 2⁺₁ state in ⁷⁴Zn. The neutron-rich ⁷⁴Zn beam was produced by in-flight fragmentation of ⁷⁶Ge at the Grand Accelerateur National d’lons Lourds and separated with the LISE spectrometer. The lifetime of the 2⁺₁ state was measured by the recoil-distance Doppler-shift method with the Cologne plunger device combined with the EXOGAM detectors. The lifetime of the 2⁺₁ state in ⁷⁴Zn was determined to be 27.0(24) ps, which corresponds to a reduced transition probability

.

Keywords: lifetime measurement, exotic nuclei

1. Introduction

There has been a continuous interest in the study of the structure effects of neutron sub-shell closure at N = 40 close to proton magicity at Z = 28. The doubly-magic character of

is originally pointed out by Bernas et al.¹ and investigated both from the theoretical and experimental points of view (see for instance Ref.¹¹ and references therein). One of the most interesting features is the sudden increase in collectivity in the vicinity of ⁶⁸Ni by an apparent over occupation of the neutron 1g_9/2 orbit.^3,4 The role of the neutron 1g_9/2 orbit in the onset of collectivity in the vicinity of ⁶⁸Ni has been debated in the past. It turns out that the lowest-lying three Nilsson orbitals originating from the spherical vg_9/2 orbital are all strongly down-sloping for both prolate and oblate shapes, which would make deformation energetically favorable in ^72–74Zn. Recent shell-model calculations also pointed out the importance of the vg_9/2 orbit to explain the evolution of collectivity around ⁶⁸Ni.^5,6

In order to investigate how collectivity develops in this region, the measurement of the reduced transition probability B(E2) gives insight into its evolution. Prior to the current work, all B(E2) values in the neutron-rich Ni and Zn isotopes were extracted from the Coulomb excitation cross sections.^3,4,7,8 Here, we report the first direct lifetime measurement of the 2⁺₁ state in ⁷⁴Zn by the recoil-distance Doppler-shift method (RDDS) method⁹ applied to the intermediate-energy inelastic scattering. The RDDS method allows a direct determination of the B(E2) strengths, thus avoiding the complex analysis of cross sections where often many unknown matrix elements have to be fitted.

2. Experiment and result

The experiment has been performed at the Grand AccéLeléLerateur National d’fIons Lourds (GANIL). A primary beam of ⁷⁶Ge at an incident beam energy of 60 MeV/nucleon was used to produce a cocktail beam of ^73,74Zn by the projectile-fragmentation reaction on a ⁹Be target. The cocktail beam was separated by the first half of the LISE spectrometer.¹⁰ The secondary beam with an energy of 34 MeV/nucleon impinging on Cologne plunger device11 consisting of a 445-µm-thick CD2 target and a 273-µm-thick Be degrader in order to induce inelastic scattering. The outgoing particles were selected and identified by the second half of LISE. Gamma rays emitted from the reaction products were detected by 8 EXOGAM detectors,¹² which were surrounding the plunger device at angles of 45 and 135 degrees relative t...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Preface
• Contents
• Photo
• GANIL-SPIRAL2: A New ERA
• Nuclear Physics in Japan and RIKEN Nishina Center
• Nuclear Physics Programs at RIBF
• Unbound States of the Drip-Line Nucleus 24O
• High-Resolution Ion-Optical Analysis of RI-Beams with the Sharaq Spectrometer
• Nuclear Moments of μ-Second Isomeric Fragments at BigRIPS
• Production of Spin-Aligned RI Beams via the Two-Step Fragmentation Reaction
• Recent Studies of Transfer Reactions with MUST 2 at GANIL and RIKEN
• Lifetime Measurement of 2+1 State in 74Zn by Recoil-Distance Doppler-Shift Method
• Recent Progress of Nuclear Density Functional Calculations: Toward to Next-Generation Supercomputer
• Tensor Correlations on Spin-Orbit Splittings and Spin Dependent Excitations
• Systematic Study of Many-Particle and Many-Hole States in and Around the “Island of Inversion”
• Coexistence of Various Deformed States and α Clustering in 42Ca
• Tops-on-Top Model for Triaxial Strongly Deformed Bands in Even-A Nuclei
• Structure Beyond the Neutron Drip-Line: 9He
• Tensor Correlation in Light Nuclei Studied with Tensor Optimized Shell Model
• Symmetry Energy, Pairing Correlations in Nuclear Matter and Giant Resonances in Tin Isotopes
• Systematic Study of E1 Mode Using Canonical-Basis TDHFB
• Studies of Light Neutron-Excess Nuclei from Bounds to Continuum
• Triaxial Nuclear Molecule 28Si – 28Si in Resonances
• Black-Sphere Approximation to Nuclei and Its Application to Reactions with Neutron-Rich Nuclei
• Beyond-Mean-Field Models for Correlated Nucleons. Applications of Second Random-Phase Approximation to 16O and 48Ca
• Derivation of the Interacting Boson Model from Mean-Field Theory
• Large-Amplitude Quadrupole Collective Dynamics in Neutron-Rich Mg and Cr Isotopes
• Microscopic Description of Large-Amplitude Collective Motions with Local QRPA Inertial Masses
• Two-Proton Radioactivity as a Tool for Nuclear Structure
• 14Be P,N 14B Reaction at 69 MeV and Proportionality Relationship Between Forward Angle P,N Cross Section and B G
• Exploring Mg Isotope Structures through Beta-Delayed Decay of Spin-Polarized Na Isotopes
• A New Method to Explore High-Spin States by RI Beam Induced Fusion Reaction
• The Super-Allowed Fermi Type Charge Exchange Reaction for Studies of Isovector Non-Spin-Flip Monopole Resonance
• Invariant-Mass Spectroscopy of the Unbound Nucleus 13Be
• Gamow-Teller Transitions in Proton Rich Nuclei Deduced from the Combined Study of β-Decay and Charge-Exchange Reactions
• Supernova Nucleosynthesis, Neutrino Mass and Oscillation, and Nuclear Weak Interactions
• KEK Isotope Separation System for β Decay Spectroscopy of R-Process Nuclei
• Spin Modes in Nuclei and Applications to Astrophysical Processes
• Proton-Capture Nucleosynthesis in Neutrino-Driven Supernova Explosions
• Momentum-Dependent Spin-Current Tensor Contribution in Collision Dynamics
• Strong Nuclear Couplings as a Source of Coulomb Rainbow and Near Barrier Fusion Suppression
• Analytic Study of the Hindered Fusion A La Recherche D’une Formule Analytique Pour La Fusion Entravee
• Studies of Fission-Yield Models
• Digital Electronics for γ-Ray Spectroscopy — The Path to Low Cross-Sections: First Evidence of a Rotational Band in 246Fm
• MINOS: A Vertex Tracker for In-Beam γ Spectroscopy at Relativistic Energies
• Elastic Scattering of Protons with Radioactive Ion Beams: Overview of ESPRI Project
• Studies of Spin-Dependent Interactions in Unstable Nuclei with Solid Polarized Proton Target
• The DESIR Facility at SPIRAL2
• Electron Scattering
• Pushing the Limits of Spectroscopy with S3
• SAMURAI: A Large-Acceptance Spectrometer in RIBF
• VAMOS: Hot News and Perspectives
• Final Remarks
• Organized in the framework of FJNSP LIA and EFES French-Japanese Symposium
• PARTICIPANTS
• PROGRAM