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How is the rapid neutron capture process terminated ? -Pioneering research with delayed fission spectroscopies-

Research Project

Project/Area Number 18H03711
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Review Section Medium-sized Section 15:Particle-, nuclear-, astro-physics, and related fields
Research InstitutionHigh Energy Accelerator Research Organization

Principal Investigator

Miyatake Hiroari  大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 教授 (50190799)

Co-Investigator(Kenkyū-buntansha) 平山 賀一  大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 研究機関講師 (30391733)
SCHURY P.H  大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 助教 (30462724)
渡邉 裕  大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 准教授 (50353363)
Project Period (FY) 2018-04-01 – 2021-03-31
Project Status Completed (Fiscal Year 2020)
Budget Amount *help
¥44,850,000 (Direct Cost: ¥34,500,000、Indirect Cost: ¥10,350,000)
Fiscal Year 2020: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2019: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2018: ¥32,370,000 (Direct Cost: ¥24,900,000、Indirect Cost: ¥7,470,000)
Keywords早い中性子捕獲過程 / 精密質量測定 / GAGG検出器 / 超微細構造測定 / 核分裂障壁測定 / 多核子移行反応 / レーザー共鳴イオン化 / 原子核質量測定 / 宇宙核物理 / 不安定原子核物理 / 核分裂 / 超重元素
Outline of Final Research Achievements

A pioneering work of the astrophysical heavy-element synthesis has been performed. It aims to study fission phenomena of synthesized isotopes in the rapid neutron capture process at explosive environments. Such isotopes can be produced through the multi-nucleon transfer reactions of uranium-beam and actinides target. And they are separated and collected with using KEK Isotope Separation System (KISS). Measurements of fission barriers and fission-fragment distributions of their beta-delayed fission phenomena will make clear the termination condition of the r-process.
New beta-ray detection system with high collection efficiency and high energy resolution has been developed in this work. And Multi-Reflection Time-of-Flight mass spectrograph (MRTOF) has been newly installed at the KISS facility. Measurements of fissions from unknown neutron-rich very heavy isotopes will be launched after the permission for use of curium target in the laboratory.

Academic Significance and Societal Importance of the Research Achievements

金・白金・ウランなどの重元素の起源は、超新星爆発や中性子合体などの爆発的天体環境における早い中性子捕獲(r-)過程だと考えられているが、定量的理解は出来てない。そこでr-過程終端部での重元素生成を調べるため、極めて重い中性子過剰核を人工的に生成し、β遅発核分裂を測定を目指して開拓的研究を開始した。これまでの研究・開発の蓄積をもとにした、世界に先駆けた研究である。
具体的には核分裂を詳細に調べるための高性能検出器の開発、未知重元素同位体の精密質量測定を行うシステムの設置を行った。今後の実験によって、中性子星合体で予測されている核分裂起源の重元素生成に定量的な判断が下せるようになるだろう。

Report

(4 results)
  • 2020 Annual Research Report   Final Research Report ( PDF )
  • 2019 Annual Research Report
  • 2018 Annual Research Report
  • Research Products

    (54 results)

All 2021 2020 2019 2018 Other

All Int'l Joint Research (14 results) Journal Article (11 results) (of which Int'l Joint Research: 8 results,  Peer Reviewed: 10 results,  Open Access: 2 results) Presentation (26 results) (of which Int'l Joint Research: 14 results,  Invited: 16 results) Remarks (3 results)

  • [Int'l Joint Research] Institute for Basic Science/Seoul National University(韓国)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Beihan University/Institute of Modern Physics(中国)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Surrey University/Brighton University(英国)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Argonne Nat. Lab.(米国)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] GSI(ドイツ)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research]

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Institute for Basic Science/Seoul National University(韓国)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Beihan University/Institute of Modern Physics(中国)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Surrey University/Brighton University(英国)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Argonne Nat. Lab.(米国)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] GSI(ドイツ)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research]

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Institute for Basic Science(韓国)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] TRIUMF(カナダ)

    • Related Report
      2018 Annual Research Report
  • [Journal Article] Three-dimensional tracking multi-segmented proportional gas counter for β-decay spectroscopy of unstable nuclei2021

    • Author(s)
      Hirayama Y.、Schury P.、Mukai M.、Choi H.、Iimura S.、Watanabe Y.X.、Wada M.、Watanabe H.、Miyatake H.
    • Journal Title

      Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

      Volume: 997 Pages: 165152-165152

    • DOI

      10.1016/j.nima.2021.165152

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] KISS Project2021

    • Author(s)
      Miyatake, H.
    • Journal Title

      AIP Conference Proceedings

      Volume: 2319 Pages: 080006-080006

    • DOI

      10.1063/5.0036990

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Nuclear spectroscopy of r-process nuclei using KEK Isotope Separation System2020

    • Author(s)
      Hirayama Y.、Watanabe Y.X.、Mukai M.、Ahmed M.、Ishiyama H.、Jeong S.C.、Kakiguchi Y.、Kimura S.、Moon J.Y.、Oyaizu M.、Park J.H.、Schury P.、Wada M.、Miyatake H.
    • Journal Title

      Journal of Physics: Conference Series

      Volume: 1643 Issue: 1 Pages: 012138-012138

    • DOI

      10.1088/1742-6596/1643/1/012138

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Properties of Ta187 Revealed through Isomeric Decay2020

    • Author(s)
      Walker P.M.、Hirayama Y.、Lane G.J.、Watanabe H.、Dracoulis G.D.、Ahmed M.、Brunet M.、Hashimoto T.、Ishizawa S.、Kondev F.G.、Litvinov Yu.A.、Miyatake H.、Moon J.Y.、Mukai M.、Niwase T.、Park J.H.、Podolyk Zs.、Rosenbusch M.、Schury P.、Wada M.、Watanabe X.Y.、Liang W.Y.、Xu F.R.
    • Journal Title

      Physical Review Letters

      Volume: 125 Issue: 19 Pages: 192505-192505

    • DOI

      10.1103/physrevlett.125.192505

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] In-gas-cell laser ionization spectroscopy of Os194,196 isotopes by using a multireflection time-of-flight mass spectrograph2020

    • Author(s)
      Choi H.、Hirayama Y.、Choi S.、Hashimoto T.、Jeong S. C.、Miyatake H.、Moon J. Y.、Mukai M.、Niwase T.、Oyaizu M.、Rosenbusch M.、Schury P.、Taniguchi A.、Watanabe Y. X.、Wada M.
    • Journal Title

      Physical Review C

      Volume: 102 Issue: 3 Pages: 034309-034309

    • DOI

      10.1103/physrevc.102.034309

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Deexcitation γ-ray transitions from the long-lived Iπ=13/2+ metastable state in Os1952020

    • Author(s)
      Watanabe Y. X.、Ahmed M.、Hirayama Y.、Mukai M.、Park J. H.、Schury P.、Kakiguchi Y.、Kimura S.、Ozawa A.、Oyaizu M.、Wada M.、Miyatake H.
    • Journal Title

      Physical Review C

      Volume: 101 Issue: 4 Pages: 041305-041305

    • DOI

      10.1103/physrevc.101.041305

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Nuclear spectroscopy of r-process nuclei using KEK Isotope Separation System2020

    • Author(s)
      Y. Hirayama, Y.X. Watanabe, M. Mukai, P. Schury, M. Ahmed, H. Ishiyama, S.C. Jeong, Y. Kakiguchi, S. Kimura, J.Y. Moon, M. Oyaizu, J.H. Park, M. Wada, H. Miyatake
    • Journal Title

      Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

      Volume: 463 Pages: 425-430

    • DOI

      10.1016/j.nimb.2019.04.035

    • Related Report
      2020 Annual Research Report 2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Development of a multi-segmented proportional gas counter for β-decay spectroscopy at KISS2020

    • Author(s)
      M. Mukai, Y. Hirayama, P. Schury, Y.X. Watanabe, M. Ahmed, H. Haba, H. Ishiyama, S.C. Jeong , Y. Kakiguchi, S. Kimura, J.Y. Moon, M. Oyaizu, A. Ozawa, J.H. Park, H. Ueno, M. Wada, H. Miyatake
    • Journal Title

      Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

      Volume: 463 Pages: 421-424

    • DOI

      10.1016/j.nimb.2019.04.036

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Efficient two-color two-step laser ionization schemes of λ1 ~250 nm and λ2 = 307.9 nm for heavy refractory elements-Measurements of ionization cross-sections and hyperfine spectra of tantalum and tungsten2019

    • Author(s)
      Y. Hirayama, M. Mukai, Y. X. Watanabe, M. Oyaizu, S. C. Jeong, Y. Kakiguchi, P. Schury, M. Wada, and H. Miyatake
    • Journal Title

      Review of Scientific Instruments

      Volume: 90 Issue: 11 Pages: 115104-115104

    • DOI

      10.1063/1.5124444

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Time-of-flight mass spectrographs of high mass resolving power2019

    • Author(s)
      Wollnik H.、Wada M.、Schury P.、Rosenbusch M.、Ito Y.、Miyatake H.
    • Journal Title

      International Journal of Modern Physics A

      Volume: 34 Issue: 36 Pages: 1942001-1942001

    • DOI

      10.1142/s0217751x19420016

    • Related Report
      2019 Annual Research Report
  • [Journal Article] KEK Isotope Separation System (KISS)2018

    • Author(s)
      Y. Watanabe, Y. Hirayama, H. Miyatake
    • Journal Title

      Nuclear Physics News

      Volume: 28 Issue: 4 Pages: 25-28

    • DOI

      10.1080/10619127.2018.1529984

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access
  • [Presentation] 非軸対称変形核192Reの基底状態からのベータ崩壊2020

    • Author(s)
      渡邉 寛
    • Organizer
      日本物理学会 2020年度 秋季大会
    • Related Report
      2020 Annual Research Report
  • [Presentation] MRTOF+α-TOFを用いた短寿命α崩壊核種の質量-崩壊特性測定2020

    • Author(s)
      庭瀬暁隆
    • Organizer
      日本物理学会 2020年度 第75回年次大会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Study of nuclear structure in the vicinity of N=126 at KISS2020

    • Author(s)
      Yoshikazu Hirayama
    • Organizer
      Vth Topical Workshop on Modern Aspects in Nuclear Structure
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] KISSでの核分光研究2020

    • Author(s)
      宮武宇也
    • Organizer
      令和元年度KUR専門研究会「短寿命RIを用いた核分光と核物性研究Ⅵ」 兼「第11回停止・低速RIビームを用いた核分光研究会」
    • Related Report
      2019 Annual Research Report
  • [Presentation] Towards precise mass measurements of Nh and Mc isotopes2019

    • Author(s)
      Michiharu Wada
    • Organizer
      4th International Symposium on Superheavy Elements
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] KISS Projewct2019

    • Author(s)
      Hiroari Miyatake
    • Organizer
      14th Asia-Pacific Physics Conference
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 第7周期元素科学:超重元素の物理と化学2019

    • Author(s)
      宮武宇也
    • Organizer
      日本物理学会2019年秋季大会 合同シンポジウム
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] Nuclear physics by multi-reflection time-of-flight mass spectrograph at WNSC2019

    • Author(s)
      Peter Schury
    • Organizer
      INPC 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nuclear spectroscopy of r-process nuclei in the vicinity of N=126 by using KISS2019

    • Author(s)
      Toshikazu Hirayama
    • Organizer
      INPC2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Recent experimental results of KEK Isotope Separation System (KISS)2019

    • Author(s)
      Yutaka Watanabe
    • Organizer
      The 13th International Conference on Stopping and Manipulation of Ions and related topics SMI-2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Present progress of researches with KISS and MRTOF2019

    • Author(s)
      Hiroari Miyatake
    • Organizer
      OMEG 15
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Towards comprehensive mass measurements with MRTOF mass spectrographs at RIKEN RIBF2019

    • Author(s)
      Michiharu Wada
    • Organizer
      2019 KPS Spring Meeting
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] Production of N=126 nuclei and beyond using multinucleon transfer reactions2019

    • Author(s)
      Yutaka Watanabe
    • Organizer
      Physics between lead and uranium: in preparation of new experimental campaigns at ISOLDE
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] Nuclear spectroscopy of r-process nuclei in the vicinity of N=126 at KISS2019

    • Author(s)
      Yoshikazu Hirayama
    • Organizer
      Physics between lead and uranium: in preparation of new experimental campaigns at ISOLDE
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] Production of N=126 nuclei and beyond using multinucleon transfer reactions Yutaka Watanabe2019

    • Author(s)
      Y. Watanabe
    • Organizer
      Physics between lead and uranium: in preparation of new experimental campaigns at ISOLDE
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nuclear spectroscopy of r-process nuclei in the vicinity of N=126 at KISS Yoshikazu Hirayama2019

    • Author(s)
      Y. Hirayama
    • Organizer
      Physics between lead and uranium: in preparation of new experimental campaigns at ISOLDE
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nuclear spectroscopy of r-process nuclei in the vicinity of N = 126 at KISS2019

    • Author(s)
      平山賀一
    • Organizer
      日本物理学会第74回年次大会シンポジウム
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] 宇宙核物理に関連する質量測定2019

    • Author(s)
      和田道治
    • Organizer
      核データと重元素合成を中心とする宇宙核物理研究会
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] KISS/MRTOFの現状2018

    • Author(s)
      宮武宇也
    • Organizer
      平成30年度KUR専門研究会「短寿命RIを用いた核分光と核物性研究Ⅴ」
    • Related Report
      2018 Annual Research Report
  • [Presentation] MRTOF Mass Spectrographs at RIKEN RIBF ---Toward Comprehensive Mass Measurements of >1000 Nuclides Including Super Heavy Nuclides2018

    • Author(s)
      M. Wada
    • Organizer
      13th International Conference on Nucleus-Nucleus Collisions (NN2018)
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] KISS and MRTOF Projects of KEK2018

    • Author(s)
      P. Schury
    • Organizer
      The 10th China-Japan Joint Nuclear Physics Symposium (CJNP 2018)
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Mass Measurements of Heavy and Superheavy Nuclei by Multi-Reflection Time-of-Flight Mass Spectrograph2018

    • Author(s)
      P. Schury
    • Organizer
      7th International Conference on Trapped Charged Particles and Fundamental Physics (TCP2018)
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] RNB project on the astrophysical element synthesis2018

    • Author(s)
      H. Miyatake
    • Organizer
      Tsukuba Global Science Week 2018 (TGSW2018)
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Nuclear production by multinucleon transfer reactions2018

    • Author(s)
      Y. Watanabe
    • Organizer
      20th Northeastern Asian Symposium on “Nuclear Physics in the 21st Century”
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Nuclear spectroscopy of r-process nuclei using KEK Isotope Separation System2018

    • Author(s)
      Y. Hirayama
    • Organizer
      XVIII The International Conference on Electromagnetic Isotope Separators and Related Topics (EMIS2018)
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] r-過程終焉部、核分裂障壁2018

    • Author(s)
      宮武宇也
    • Organizer
      「超重元素研究の新展開」研究会
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Remarks] 高エネルギー加速器研究機構素粒子原子核研究所和光原子核科学センター

    • URL

      https://research.kek.jp/group/wnsc/

    • Related Report
      2020 Annual Research Report
  • [Remarks]

    • URL

      http://research.kek.jp/group/wnsc/

    • Related Report
      2019 Annual Research Report
  • [Remarks] KEK Wako Nuclear Science Center

    • URL

      http://research.kek.jp/group/wnsc/

    • Related Report
      2018 Annual Research Report

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Published: 2018-04-23   Modified: 2022-01-27  

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