Search for rare gamma-decay modes to understand nucleosynthesis in the universe

• Project/Area Number: 15H02091
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka University (2017-2019); Kyoto University (2015-2016)
• Principal Investigator: KAWABATA Takahiro 大阪大学, 理学研究科, 教授 (80359645)
• Co-Investigator(Kenkyū-buntansha): 久保野 茂 国立研究開発法人理化学研究所, 仁科加速器科学研究センター, 客員主管研究員 (20126048) ; 伊藤 正俊 東北大学, サイクロトロン・ラジオアイソトープセンター, 教授 (30400435) ; 松田 洋平 東北大学, サイクロトロン・ラジオアイソトープセンター, 助教 (50569043) ; 秋宗 秀俊 甲南大学, 理工学部, 教授 (60319829)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥42,380,000 (Direct Cost: ¥32,600,000、Indirect Cost: ¥9,780,000); Fiscal Year 2018: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000); Fiscal Year 2017: ¥7,410,000 (Direct Cost: ¥5,700,000、Indirect Cost: ¥1,710,000); Fiscal Year 2016: ¥13,130,000 (Direct Cost: ¥10,100,000、Indirect Cost: ¥3,030,000); Fiscal Year 2015: ¥16,120,000 (Direct Cost: ¥12,400,000、Indirect Cost: ¥3,720,000)
• Keywords: トリプルアルファ反応 / 宇宙における元素合成過程 / 固体水素標的 / 稀ガンマ崩壊 / 宇宙における元素合成 / 実験核物理 / ガンマ崩壊幅 / 陽子非弾性散乱 / 逆運動学 / 元素合成 / 極薄固体水素標的 / GAGGシンチレータ

Outline of Final Research Achievements

The triple alpha reaction is one of the most important reactions in the nuclear astrophysics. However, its reaction rate in high temperature environments at T > 2 GK was still uncertain because the gamma-decay probability of the 9.64-MeV state in 12C as a key parameter to estimate the reaction rate was unknown. In the present work, we have developed a new solid-hydrogen target system and the Gion recoil-particle counter telescope, and have measured the gamma-decay probability of the 9.64-MeV state for the first time by measuring the 1H(12C,12Cp) reaction, and found that the 9.64-MeV state noticeably enhances the triple alpha reaction rate.

Academic Significance and Societal Importance of the Research Achievements

トリプルアルファ反応は、元素合成が質量数5ないしは8において停滞するという、いわゆる「質量数5と8の壁」を乗り越え全ての重元素合成の戸口となる反応であり、宇宙における元素合成過程において最も重要な反応である。これまで、NACREと呼ばれる核反応率ライブラリに収録された推定値が天体核計算に広く用いられてきたが、20億Kを超える高温度下におけるトリプルアルファ反応率には大きな不定性が残されていた。今回の研究成果により、高温度下における反応率が明らかとなり、不定性が劇的に低減された。宇宙における元素合成過程の理解に大きく寄与するものと期待される。

Research Products

• [Int'l Joint Research] ブリュッセル自由大学(ベルギー)
• [Int'l Joint Research] ブリュッセル自由大学(ベルギー)
• [Journal Article] 原子核におけるクラスター構造と宇宙における元素合成過程 (2020)
  • Author(s): 川畑貴裕
  • Journal Title: 原子核研究 Volume: 64 Supplement 1
• [Journal Article] Neutron quadrupole transition strength in C10 deduced from the C10(α,α′) measurement with the MAIKo active target (2019)
  • Author(s): Furuno T.、Kawabata T.、Adachi S.、Ayyad Y.、Kanada-En'yo Y.、Fujikawa Y.、Inaba K.、Murata M.、Ong H. J.、Sferrazza M.、Takahashi Y.、Takeda T.、Tanihata I.、Tran D. T.、Tsumura M.
  • Journal Title: Physical Review C Volume: 100
  • DOI: 10.1103/physrevc.100.054322
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Nuclear experimental approaches towards nucleosynthesis in the universe (2019)
  • Author(s): Kawabata Takahiro
  • Journal Title: AIP Conference Proceedings Volume: 2076
  • DOI: 10.1063/1.5091634
  • Peer Reviewed / Open Access
• [Journal Article] Performance test of the MAIKo active target (2018)
  • Author(s): Furuno T.、Kawabata T.、Ong H.J.、Adachi S.、Ayyad Y.、Baba T.、Fujikawa Y.、Hashimoto T.、Inaba K.、Ishii Y.、Kabuki S.、Kubo H.、Matsuda Y.、Matsuoka Y.、Mizumoto T.、Morimoto T.、Murata M.、Sawano T.、Suzuki T.、Takada A.、Tanaka J.、Tanihata I.、Tanimori T.、Tran D.T.、Tsumura M.、Watanabe H.D.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 908 Pages: 215-224
  • DOI: 10.1016/j.nima.2018.08.042
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Systematic analysis of inelastic $\ensuremath{\alpha}$ scattering off self-conjugate $A=4n$ nuclei (2018)
  • Author(s): S. Adachi, S. Sakaguchi (39人中28番目), et al.
  • Journal Title: Physical Review C Volume: 97 Pages: 014601-014601
  • DOI: 10.1103/physrevc.97.014601
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Time-Reversal Measurement of the p-Wave Cross Section of the 7Be(n,a) Reaction for the Cosmological Li Problem (2017)
  • Author(s): T. Kawabata, et al.
  • Journal Title: Phys. Rev. Lett. Volume: 118 Pages: 052701-052701
  • DOI: 10.1103/physrevlett.118.052701
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Nuclear Astrophysics at RCNP (2019)
  • Author(s): Kawabata Takahiro
  • Organizer: JSPS/NRF/NSCF A3 Foresight Progarm “Nuclear Physics in the 21st Centruy” Joint Kick Off Meeting
  • Int'l Joint Research / Invited
• [Presentation] Search for Rare γ-decay Modes in 12C and Recent Activities of Kyoto-Osaka Experimental Nuclear Cluster Physics Group (2019)
  • Author(s): Kawabata Takahiro
  • Organizer: ECT* Trento Workshop on “Light clusters in nuclei and nuclear matter: Nuclear structure and decay, heavy-ion collisions, and astrophysics”
  • Int'l Joint Research
• [Presentation] 極端環境下におけるトリプルアルファ反応率 (2019)
  • Author(s): 川畑貴裕
  • Organizer: 宇宙核物理連絡協議会研究会
  • Invited
• [Presentation] Nuclear experimental approach to cluster correlation and nucleosynthesis in the universe (2019)
  • Author(s): Kawabata Takahiro
  • Organizer: The 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15)
  • Int'l Joint Research / Invited
• [Presentation] ニューラルネットワークを用いたMAIKo TPCの飛跡データの解析 (2019)
  • Author(s): 土井隆暢, 川畑貴裕, 古野達也
  • Organizer: 日本物理学会第74回年次大会
• [Presentation] ニューラルネットワークを用いたTPCの飛跡検出法の開発 (2019)
  • Author(s): 土井隆暢, 川畑貴裕, 古野達也
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Search for rare γ-decay modes in 12C (2018)
  • Author(s): T. Kawabata, M. Tsumura and Y. Takahashi, for RCNP E404 Collaboration
  • Organizer: The 4th International Workshop on State of the Art in Nuclaer Cluster Physics (SOTANCP4)
  • Int'l Joint Research
• [Presentation] Present Status of the Cosmological Lithium Problem (2018)
  • Author(s): 川畑貴裕
  • Organizer: 日本物理学会第73回年次大会
  • Invited
• [Presentation] Direct measurement of the 7Be(n,α)4He reaction cross sections for the cosmological Li problem (2017)
  • Author(s): T. Kawabata, T. Furuno, T. Hashimoto, M. Ichikawa, M. Itoh, N. Iwasa, Y. Kanada-En'yo, A. Koshikawa, S. Kubono, E. Miyawaki, K. Mizutani, T. Morimoto, M. Murata, T. Nanamura1 S. Nishimura, R. Sawada, T. Takeda, M. Tsumura, K. Watanabe, and S. Yoshida
  • Organizer: 7th International Conference on Heavy-Ion Collisions at Near-Barrier Energies (FUSION17)
  • Place of Presentation: Hobart, Tasmania, Australia
  • Year and Date: 2017-02-20
  • Int'l Joint Research / Invited
• [Presentation] 宇宙リチウム問題のための7Be(n,α)4He反応断面積の直接測定 (2017)
  • Author(s): 川畑貴裕
  • Organizer: 宇宙核物理連絡協議会研究会,
  • Invited
• [Presentation] シンクロトロン施設における逆コンプトンガンマ線生成と原子核物理への応用 (2017)
  • Author(s): 川畑貴裕
  • Organizer: シンクロトロン光が拓く学際的物理研究の可能性
  • Invited
• [Presentation] Direct measurement of the 7Be(n,α)4He reaction cross sections for the cosmological lithium problem (2017)
  • Author(s): 川畑貴裕
  • Organizer: the Korean Physics Society Fall Meeting
  • Int'l Joint Research / Invited
• [Presentation] Alpha inelastic scattering and cluster structures in stable and unstable nuclei (2017)
  • Author(s): 川畑貴裕
  • Organizer: the International workshop on Hadron and Nuclear Physics 2017 (HNP2017)
  • Int'l Joint Research / Invited
• [Presentation] The first measurement of cross section for the 7Be(n,α)4He reaction near the threshold energy (2016)
  • Author(s): T. Kawabata, T. Furuno, M. Ichikawa , N. Iwasa, Y. Kanada-En'yo, A. Koshikawa, S. Kubono, E. Miyawaki, T. Morimoto, M. Murata, T. Nanamura, S. Nishimura, Y. Shikata, Y. Takahashi, T. Takeda, M. Tsumura, and K. Watanabe
  • Organizer: International Nuclear Physics Conference (INPC2016)
  • Place of Presentation: Adelaide Convention Centre, Adelaide, Australia
  • Year and Date: 2016-09-11
  • Int'l Joint Research
• [Presentation] Search for the rare γ-decay mode in 12C (2016)
  • Author(s): M. Tsumura, T. Kawabata
  • Organizer: he 14th International Symposium on Nuclei in the Cosmos XIV (NIC-XIV)
  • Place of Presentation: Toki Messe, Niigata, Japan
  • Year and Date: 2016-06-19
  • Int'l Joint Research
• [Presentation] Search for the rare gamma-decay mode in 12C (2016)
  • Author(s): M. Tsumura, T. Kawabata, S. Adachi, T. Furuno, A. Koshikawa, M. Murata, T. Morimoto, A. Tamii, T. Hashimoto, K. Hatanaka, Y. Matsuda, K. Miki, C. Iwamoto, T. Itoh, M. Miura, J. Zenihiro, S. Kubono, M. Itoh, Y. Maeda, S. Sakaguchi, H. Akimune, H. Fujimura, I. Ou
  • Organizer: Symposium on Nuclei in the Cosmos
  • Place of Presentation: 新潟市朱鷺メッセ
  • Year and Date: 2016-06-19
  • Int'l Joint Research
• [Presentation] Search for the rare gamma-decay mode in 12C (2016)
  • Author(s): M. Tsumura, T. Kawabata, S. Adachi, T. Furuno, A. Koshikawa, M. Murata, T. Morimoto, A. Tamii, T. Hashimoto, K. Hatanaka, Y. Matsuda, K. Miki, C. Iwamoto, T. Itoh, M. Miura, J. Zenihiro, S. Kubono, M. Itoh, Y. Maeda, S. Sakaguchi, H. Akimune, H. Fujimura, I. Ou
  • Organizer: 11th International Conference on Clustering Aspects of Nuclear Structure and Dynamics
  • Place of Presentation: イタリア ナポリ
  • Year and Date: 2016-05-23
  • Int'l Joint Research
• [Presentation] GAGGを用いた荷電粒子検出器の性能評価 (2016)
  • Author(s): 越川亜美, 川畑貴裕, 古野達也, 津村美保, 村田求基, 森本貴博, 黒澤俊介, 山路晃宏, 村上力輝斗, 堀合毅彦, 知場啓志
  • Organizer: 日本物理学会第71回年次大会
  • Place of Presentation: 東北学院大学
  • Year and Date: 2016-03-16
• [Remarks] 大阪大学大学院理学研究科 物理学専攻 原子核実験研究室
  • URL: http://nucl.phys.sci.osaka-u.ac.jp/
• [Remarks] 大阪大学大学院 理学研究科物理学専攻 原子核実験研究室
  • URL: http://nucl.phys.sci.osaka-u.ac.jp/
• [Funded Workshop] The 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15) (2019)