Study of origin of heavy elements using intense neutron beam

2014 Fiscal Year Final Research Report

• Project/Area Number: 24340060
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: HAYAKAWA Takehito 独立行政法人日本原子力研究開発機構, 原子力科学研究部門 量子ビーム応用研究センター, 研究主幹 (70343944)
• Co-Investigator(Kenkyū-buntansha): SHIZUMA Toshiyuki 独立行政法人日本原子力研究開発機構, 原子力科学研究部門量子ビーム応用研究センター, 研究主幹 (50282299) ; TOH Yousuke 独立行政法人日本原子力研究開発機構, 原子力科学研究部門原子力基礎工学研究センター, 研究主幹 (60354734) ; KAJINO Toshitaka 自然科学研究機構国立天文台, 理論研究部, 准教授 (20169444)
• Co-Investigator(Renkei-kenkyūsha): NAKAMURA Shoji 独立行政法人日本原子力研究開発機構, 原子力科学研究部門原子力基礎工学研究センター, 研究主幹 (90421461) ; KIMURA Atsushi 独立行政法人日本原子力研究開発機構, 原子力科学研究部門原子力基礎工学研究センター, 研究主幹 (30360423)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 宇宙核物理学

Outline of Final Research Achievements

Many isotopes heavier than iron are synthesized by the slow neutron capture reaction process (s-process) in stars. Isomers in stable isotopes have sometimes an important role as a branching point in nucleosynthesis flow in the s-process. An isomer with a half-life of 14.1 y in 113Cd is a branching point from which a nucleosynthesis flow reaches to a rare isotope 115Sn. The astrophysical origin of 115Sn has remained still an open question. The s-process abundance of 115Sn depends on the ratio of the 112Cd(n, γ)113Cdm reaction cross section to the 112Cd(n, γ)113Cdgs reaction cross section. However, the isomer production ratio following the neutron capture reaction has not been measured in the energy region higher than the thermal energy. An intense neutron beam experimental system ANNRI in J-PARC has a high purity germanium (HPGe) detector system consisting of two cluster detectors. We measuredγ-rays using the HPGe detectors in conjunction with a time-of-flight method at ANNRI.

Free Research Field

実験核物理学