New probe for neutron anisotropy generated by linearly polarized gamma-rays

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03665
• 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: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: Hayakawa Takehito 国立研究開発法人量子科学技術研究開発機構, 高崎量子応用研究所 東海量子ビーム応用研究センター, 上席研究員(定常) (70343944)
• Co-Investigator(Kenkyū-buntansha): 梶野 敏貴 国立天文台, 理論研究部, 准教授 (20169444) ; 静間 俊行 国立研究開発法人量子科学技術研究開発機構, 高崎量子応用研究所 東海量子ビーム応用研究センター, 上席研究員(定常) (50282299) ; 緒方 一介 大阪大学, 核物理研究センター, 准教授 (50346764) ; 宮本 修治 兵庫県立大学, 高度産業科学技術研究所, 教授 (90135757) ; 菊地 右馬 大阪市立大学, 大学院理学研究科, 特任講師 (00648024)
• Co-Investigator(Renkei-kenkyūsha): AMANO Sho 兵庫県立大学, 高度産業科学技術研究所, 助教 (50271200)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: レーザーコンプトン散乱γ線 / 光核反応

Outline of Final Research Achievements

In 1957, Agodi predicted that the neutron angular distribution in (gamma, n) reactions with a 100% linearly polarized gamma-ray beam for dipole excitation should be anisotropic and universally described by the simple function of a + b cos(2φ) at the polar angle θ=90 degree, where θ is the azimuthal angle. However, this prediction has not been experimentally confirmed in over half a century. We have measured the azimuthal anisotropy of neutrons emitted from the 56Fe(gamma, n)55Fe reaction with a linearly polarized gamma-ray beam generated by laser Compton scattering with laser on a single bunch electron with an energy of 1 GeV stored the NewSUBARU synchrotron radiation ring. The azimuthal anisotropy of the neutrons has been well reproduced using a theoretically predicted function of a + b cos(2φ). We have calculated the anisotropy on 9Be considering the nuclear structures. The result indicates that the anisotropy is sensitive to the excitation station.

Free Research Field

実験原子核物理学