A new measurement of 8Li(a,n)11B-reaction cross section

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K05472
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka Electro-Communication University
• Principal Investigator: MIZOI YUTAKA 大阪電気通信大学, 共通教育機構, 教授 (30388392)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: ビッグバン元素合成 / 超新星爆発 / rプロセス / 不安定核反応

Outline of Final Research Achievements

Nucleosynthesis processes taking place after a big bang and a supernova explosion are studied for many decades. Recently, studies of nuclear reactions concerning to cosmological nucleosynthesis using unstable-nuclei beams are intensively performed with development of accelerators and RI-beam techniques, in addition to studies using stable-nuclei beams. Especially, it is considered that 8Li might be a key element and the 8Li(α,n)11B should be a key reaction to produce heaver elements more than mass number of 12. Many research groups were published its reaction cross-section data, but we have not yet had any reliable result. We have controversial differences in these published cross-section data. The reason of their differences are not resolved. By the present work, we shows the clue to resolve the controversial difference and determine the reliabilities of their cross section data.

Free Research Field

原子核物理学

Academic Significance and Societal Importance of the Research Achievements

我々の世界を成す元素の起源を明らかにすることは、宇宙開闢から現在に至る宇宙の進化の謎を解き明かすことにつながる。元素は、宇宙の進化の過程で基本的な粒子から合成されてきたと考えられており、元素合成に関わる原子核反応についての研究が盛んにおこなわれている。特に8Liという放射性同位元素の関わる原子核反応の重要性が指摘され、我々も含め世界中の研究者がその原子核反応の高精度の測定を試みてきた。それらの測定結果には、実験方法に起因すると考えられる不一致が見られ、その不一致が元素合成の理論の精度に影響を与えている。本研究はその不一致の原因を解明するための新たな実験を行い、解明のヒントを得ることができた。