Study of isospin dependence in nuclear-matter equation of state via giant resonances in isobaric nuclei

• Project/Area Number: 16H06003
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: OTA Shinsuke 東京大学, 大学院理学系研究科(理学部), 助教 (60548840)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥23,270,000 (Direct Cost: ¥17,900,000、Indirect Cost: ¥5,370,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥16,120,000 (Direct Cost: ¥12,400,000、Indirect Cost: ¥3,720,000); Fiscal Year 2016: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
• Keywords: 核物質 / 中性子星 / 状態方程式 / アクティブ標的 / 大強度RIビーム / 巨大共鳴 / 不安定核 / 非弾性散乱 / 荷電依存性 / 中性子星物質 / 高速応答位置検出器 / 核物質状態方程式 / 同重体 / TPC / 重陽子非弾性散乱

Outline of Final Research Achievements

We developed a gaseous active target CAT-M aiming at high luminosity and a strip-readout parallel-plate avalanche counter SR-PPAC aiming at an effective use of high-intensity heavy-ion beams. Deuteron inelastic scattering on xeon-132 nuclei has been measured with the high-intensity beam more than five hundred thousand particles per second using these cutting-edge detector systems. This allows systematic measurements of isoscalar giant monopole resonances in isobaric nuclei for the determination of the isospin dependence of the incompressibility apart from an uncertainty due to the mass number dependence.

Academic Significance and Societal Importance of the Research Achievements

中性子星は、連星合体によって金などの鉄より重い元素を生み出す、いわば元素の生みの親とも言える星であるがその構造については未解明である。本研究はその解明に必須である核物質状態方程式の決定を目指して、試金石たる非圧縮率の荷電依存項を実験的に決定することを目的とし、同重体とよばれる質量数が同数のさまざまな原子核の密度圧縮振動状態のエネルギーを測定する。従来の１０倍の効率を実現するため、アクティブ標的 CAT-M とビーム粒子検出器 SR-PPAC を新たに開発し、キセノンの質量数１３２同重体での測定を実現した。これにより新たな研究の道筋が切り拓かれた。

Research Products

• [Int'l Joint Research] Institute of Modern Physics/Beihang University(中国)
• [Int'l Joint Research] University of Notre Dame(米国)
• [Int'l Joint Research] KVI(オランダ)
• [Int'l Joint Research] GSI/TU Darmstadt(ドイツ)
• [Int'l Joint Research] Le Centre CEA de Saclay(フランス)
• [Int'l Joint Research] Institute of Modern Physics/Beihang University(中国)
• [Int'l Joint Research] University of Notre Dame(米国)
• [Int'l Joint Research] CEA, Saclay(フランス)
• [Int'l Joint Research] GSI(ドイツ)
• [Int'l Joint Research] KVI(オランダ)
• [Int'l Joint Research] ノートルダム大学(米国)
• [Int'l Joint Research] Institute of Modern Physics(中国)
• [Int'l Joint Research] ノートルダム大学(米国)
• [Presentation] 大強度重イオンビーム照射下でのアクティブ標的CATにおけるイオンバックフローの抑制 (2020)
  • Author(s): 遠藤史隆、大田晋輔ほか
  • Organizer: 日本物理学会第７５回年次大会
• [Presentation] 大強度RIビーム実験における高速応答飛跡検出器SR-PPACの性能評価 (2020)
  • Author(s): 花井周太郎、大田晋輔
  • Organizer: 日本物理学会第７５回年次大会
• [Presentation] 不安定核132Snの逆運動学陽子弾性散乱測定 (2020)
  • Author(s): 原田知也ほか
  • Organizer: 日本物理学会第７５回年次大会
• [Presentation] Ktau from ISGMR Measurements on and around 132Sn (2019)
  • Author(s): Shinsuke OTA
  • Organizer: Gordon Research Conference, Nuclear Chemistry, "Exploring Simple Structure Patterns and the Dynamics of Nuclei"
  • Int'l Joint Research / Invited
• [Presentation] Research of isoscalar Giant Monopole Resonances using Gaseous Active Target (2019)
  • Author(s): Shinsuke OTA
  • Organizer: 14th Asia-Pacific Physics Conference (APPC 2019)
  • Int'l Joint Research
• [Presentation] Giant Resonances in Tin-region nuclei studied using gaseous active target (2019)
  • Author(s): Shinsuke OTA
  • Organizer: Vth Topical Workshop on Modern Aspects in Nuclear Structure
  • Int'l Joint Research
• [Presentation] 大強度重イオンビーム照射用低圧ガスアクティブ標的CATの開発と現状 (2019)
  • Author(s): 大田晋輔、遠藤史隆
  • Organizer: マイクロパターンガス検出器(MPGD)・アクティブ媒質TPC合同研究会
• [Presentation] Development of new type of PPAC for high intensity RI beam (2019)
  • Author(s): 花井周太郎
  • Organizer: Advanced Nuclear Reactions and Applications in Astrophysics
  • Int'l Joint Research
• [Presentation] Development of Strip Readout Parallel Plate Avalanche Counter (2019)
  • Author(s): Shutaro Hanai
  • Organizer: The 18th CNS Summer School (CNSSS19)
  • Int'l Joint Research
• [Presentation] Experimenta study of the isospin dependence of nuclear incompressibility (2018)
  • Author(s): Shinsuke OTA
  • Organizer: 5th joint meeting of the APS and JPS
  • Int'l Joint Research / Invited
• [Presentation] CNS Active Target (CAT) for high-intensity heavy-ion beam experiment (2018)
  • Author(s): Hiroshi TOKIEDA
  • Organizer: 5th joint meeting of the APS and JPS
  • Int'l Joint Research / Invited
• [Presentation] Performance evaluation of Dual Gain Multi-layer Thick GEM for CAT with high-intensity heavy-ion beams (2018)
  • Author(s): Chihiro IWAMOTO
  • Organizer: 5th joint meeting of the APS and JPS
  • Int'l Joint Research
• [Presentation] Giant resonances in Tin-region nuclei (2018)
  • Author(s): Shinsuke OTA
  • Organizer: 6th International Conference on Collective Motion in Nuclei under Extreme Conditions
  • Int'l Joint Research / Invited
• [Presentation] Active target technique for medium-heavy high-intensity heavy-ion beams (2018)
  • Author(s): Shinsuke OTA
  • Organizer: 10th China Japan Joint Symposium
  • Int'l Joint Research / Invited
• [Presentation] Active Targets CATs' for missing mass spectroscopy with high-intensity beams (2018)
  • Author(s): 大田 晋輔
  • Organizer: Workshop on Active Targets and Time Projection Chambers for High-intensity and Heavy-ion beams in Nuclear Physics
  • Int'l Joint Research / Invited
• [Presentation] Equation of State of Nuclear Matter from Direct Reactions (2017)
  • Author(s): 大田 晋輔
  • Organizer: Workshop on RI and Heavy-ion Science
  • Int'l Joint Research / Invited
• [Presentation] ガスアクティブ標的CATの大型化に向けた二重増幅率制御型多層THGEMの開発 (2017)
  • Author(s): 岩本 ちひろ
  • Organizer: 日本物理学会２０１７年秋季大会
• [Presentation] CNS Active Target (2017)
  • Author(s): 大田 晋輔
  • Organizer: 新学術領域「中性子星核物質」第二回検出器ワークショップ
  • Invited
• [Presentation] 重水素アクティブ標的を用いた錫領域不安定核の巨大単極共鳴の測定 (2017)
  • Author(s): 大田 晋輔
  • Organizer: 日本物理学会 第７２回年次大会
• [Presentation] CNS Active Target (CAT) for high-intensity beam experiment and the first experiment at RIBF (2016)
  • Author(s): 大田 晋輔
  • Organizer: Workshop on Software for Time Projection Chambers for Nuclear Physics Experiments
  • Int'l Joint Research / Invited
• [Presentation] Simulation for high-intensity heavy-ion beam injection in CAT (2016)
  • Author(s): 岩本 ちひろ
  • Organizer: Workshop on Software for Time Projection Chambers for Nuclear Physics Experiments
  • Int'l Joint Research / Invited
• [Presentation] Event Search Algorithm for CAT (2016)
  • Author(s): 時枝 紘史
  • Organizer: Workshop on Software for Time Projection Chambers for Nuclear Physics Experiments
  • Int'l Joint Research / Invited
• [Remarks] アクティブ標的プロジェクト
  • URL: http://www.cns.s.u-tokyo.ac.jp/~ota/ja/project/cat/
• [Remarks] 核物質の状態方程式
  • URL: http://www.cns.s.u-tokyo.ac.jp/~ota/ja/project/nuclear-matter/
• [Remarks] CNS Active Target
  • URL: http://www.cns.s.u-tokyo.ac.jp/~ota/ja/project/cat/