Study of neutron-rich nuclei in "island of inversion" by nuclear physics and atomic physics

• Project/Area Number: 15H03659
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka University
• Principal Investigator: Odahara Atsuko 大阪大学, 理学研究科, 准教授 (30264013)
• Co-Investigator(Kenkyū-buntansha): 下田 正 大阪大学, 理学研究科, 教授 (70135656)
• Co-Investigator(Renkei-kenkyūsha): MATSUO Yukari 法政大学, 理工学部, 教授 (50231593) ; HATAKEYAMA Atsushi 東京農工大学, 工学部, 准教授 (70345073)
• Research Collaborator: LASSEN Jens TRIUMF, Laser Applications, Group Leader ; LEVY Phil TRIUMF, Resonant Ionization Laser Ion Source group, Senior Scientist ; PEARSON Matt TRIUMF, Laser Spectroscopy group, Senior Scientist
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000); Fiscal Year 2017: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2016: ¥7,540,000 (Direct Cost: ¥5,800,000、Indirect Cost: ¥1,740,000); Fiscal Year 2015: ¥6,890,000 (Direct Cost: ¥5,300,000、Indirect Cost: ¥1,590,000)
• Keywords: スピン偏極ビーム / 超微細構造 / 新奇レーザー分光法の開発 / 中性子過剰核 / 32Na / 32Mg / 魔法数20の消失 / スピン・パリティの決定 / 実験核物理 / レーザー光ポンピング / 原子核構造 / 実験核実験 / レーザーポンピング / 偏極ビーム / ベータ線非対称度測定

Outline of Final Research Achievements

The neutron-rich nuclei in "island of inversion" around N=20 have exotic structure, which is the disappearance of magic number 20 with deformed shape. We have systematically studied nuclear structure of these nuclei by our unique method which can exactly determine the spin-parity by the beta decay of spin-polarized nucleus. In order to produce high polarization, information of hyperfine structure is needed. We developed new laser spectroscopy method to determine hyperfine structure of atoms of neutron-rich nuclei with beam intensity of < 100 particles par second. By using this new method, not only hyperfine structure but also the nuclear structure of the ground state can be investigated. After developing the spin-polarized beam, we can study nuclear structure of the excited states in neutron-rich nuclei far from beta-stability line.

Research Products

• [Int'l Joint Research] TRIUMF(カナダ)
• [Int'l Joint Research] TRIUMF(カナダ)
• [Int'l Joint Research] TRIUMF(カナダ)
• [Journal Article] Shape coexistence in the N=19 neutron-rich nucleus 31Mg explored by β-γ spectroscopy of spin-polarized 31Na (2017)
  • Author(s): H.Nishibata, T.Shimoda, A.Odahara, S.Morimoto, S.Kanaya, A.Yagi, H.Kanaoka, M.R.Pearson, C.D.P.Levy, M.Kimura
  • Journal Title: Physics Letters Volume: B767 Pages: 81-85
  • DOI: 10.1016/j.physletb.2017.01.049
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Shape coexistence in the N=19 neutron-rich nucleus 31Mg explored by β-γ spectroscopy of spin-polarized 31Na (2017)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Kanaya, A. Yagi, H. Kanaoka, M.R. Pearson, C.D.P. Levy, M. Kimura
  • Journal Title: RIKEN Accel. Prog. Rep. Volume: 50 Pages: 82-82
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Shape coexistence in the N=19 neutron-rich nucleus 31Mg explored by β-γ spectroscopy of spin-polarized 31Na (2017)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Kanaya, A. Yagi, H. Kanaoka, M.R. Pearson, C.D.P. Levy, M. Kimura
  • Journal Title: RIKEN Accel. Prog. Rep. Volume: 50 Pages: 82-82
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Shape coexistence in neutron-rich 31Mg investigated by beta-gamma spectroscopy of spin-polarized 31Na (2017)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Kanaya, A. Yagi, H. Kanaoka, M.R. Pearson, C.D.P. Levy, M. Kimura
  • Organizer: The third International Conference on Advances in Radioactive Isotope Science (ARIS2017), May 28-June 2 (2017) Colorado, US
  • Int'l Joint Research
• [Presentation] Spectroscopy of neutron unbound states in 31Mg and shape coexistence in low excitation energy region (2017)
  • Author(s): S. Kanaya, T. Shimoda, A. Odahara, H. Nishibata, S. Morimoto, A. Yagi, H. Kanaoka, T. Kawamura, M. Pearson, C.D.P. Levy
  • Organizer: Ito International Research Center (IIRC) Symposium 'Perspectives of the Physics of Nuclear Structure', July 1-4 (2017) Tokyo, Japan
  • Int'l Joint Research
• [Presentation] 中性子過剰核31Mgの中性子非束縛状態における変形共存探索 (2017)
  • Author(s): 金谷晋之介，下田正，小田原厚子，西畑洸希，森本翔太，八木彩祐未，金岡裕志，河村嵩之，M. Pearson，C. D. P. Levy
  • Organizer: 日本物理学会 秋季大会、宇都宮大学、2017年9月
• [Presentation] 中性子過剰核の変形共存 中性子非束縛状態における探索 (2017)
  • Author(s): 金谷晋之介, 下田正, 小田原厚子, 西畑洸希, 森本翔太, 八木彩祐未, 金岡裕志, 河村嵩之, M. Pearson, C. D. P. Levy
  • Organizer: 日本物理学会年次大会、大阪大学、2017年3月
• [Presentation] Shape coexistence in neutron-rich 31Mg investigated by beta-gamma spectroscopy of spin-polarized 31Na (2017)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Kanaya, A. Yagi, H. Kanaoka, M.R. Pearson, C.D.P. Levy, M. Kimura
  • Organizer: The third International Conference on Advances in Radioactive Isotope Science (ARIS2017), May 28- June 2 (2017) Colorado, US
  • Int'l Joint Research
• [Presentation] Structure of neutron-rich Mg isotopes studied in decay spectroscopy of spin-polarized Na isotopes (2016)
  • Author(s): T. Shimoda
  • Organizer: Int. Conf. on HYPERFINE interactions and their applications (HYPERFINE 2016), July 3-8 (2016) Leuven, Belgium
  • Int'l Joint Research / Invited
• [Presentation] Various Structure In Neutron-rich 31Mg Studied By Using Spin-polarized 31Na Beam (2016)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Yoshida, A. Yagi, H. Kanaoka, T. Kawamura, A. Nakahashi, T. Fujiwara, T. Yoshizumi, M. Pearson, C. D. P. Levy
  • Organizer: The 26th International Nuclear Physics Conference (INPC2016), Sep. 11-16 (2016) Adelaide, Australia
  • Int'l Joint Research
• [Presentation] Various structures of the neutron-rich nucleus 31Mg investigated by beta-gamma spectroscopy of spin-polarized 31Na (2016)
  • Author(s): H. Nishibata, T. Shimoda, A. Odahara, S. Morimoto, S. Yoshida, A. Yagi, H. Kanaoka, T. Kawamura, A. Nakahashi, T. Fujiwara, T. Yoshizumi
  • Organizer: The 22nd International Spin Symposium (SPIN2016), Sep. 25-30 (2016) Illinois, US
  • Int'l Joint Research / Invited
• [Presentation] Shape evolution and shape coexistence studied with radioactive nuclear beams (2015)
  • Author(s): A. Odahara
  • Organizer: Int. Symp. on Frontier of gamma-ray Spectroscopy
  • Place of Presentation: Osaka, Japan
  • Year and Date: 2015-10-01
  • Int'l Joint Research
• [Presentation] Study of exotic structures in neutron-rich 30Mg and 31Mg by spin-polarized radioactive beam (2015)
  • Author(s): H. Nishibata
  • Organizer: Int. Symp. on Frontier of gamma-ray Spectroscopy
  • Place of Presentation: Osaka, Japan
  • Year and Date: 2015-10-01
  • Int'l Joint Research
• [Presentation] 偏極不安定核Naビームを用いた中性子過剰Mg同位体の構造研究 (2015)
  • Author(s): 西畑洸希, 下田正, 小田原厚子, 森本翔太, 吉田晋之介, 八木彩祐未, 金岡裕志, 河村嵩之, 中橋晶, 藤原智貴, 吉住孝之, M. Pearson, C. D. P. Levy
  • Organizer: 日本物理学会 秋季大会
  • Place of Presentation: 大阪市大
  • Year and Date: 2015-09-25
• [Presentation] スピン偏極した31Naのベータ遅延中性子崩壊で探る31Mgの中性子非束縛状態の研究 (2015)
  • Author(s): 森本翔太, 下田正, 小田原厚子, 西畑洸希, 吉田晋之介, 八木彩祐未, 金岡裕志, 河村嵩之, 中橋晶, 藤原智貴, 吉住孝之, M. Pearson, C. D. P. Levy
  • Organizer: 日本物理学会 秋季大会
  • Place of Presentation: 大阪市大
  • Year and Date: 2015-09-25
• [Remarks] 大阪大学大学院理学研究科物理学専攻重イオン核物理グループ（下田研究室）
  • URL: http://adam.phys.sci.osaka-u.ac.jp/
• [Remarks] 大阪大学大学院理学研究科物理学専攻重イオン核物理グループ（下田研究室）
  • URL: http://adam.phys.sci.osaka-u.ac.jp