Development of muonic hel;ium beam for measuring neutrino mass

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K12495
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: Osaka University
• Principal Investigator: Tomono Dai 大阪大学, 核物理研究センター, 特任助教(常勤) (40415245)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: ミューオン / ミューオン原子

Outline of Final Research Achievements

In order to measure the neutrino mass kinematically by investigating the decay of　triton and muon neutrinos in the reaction of helium-3 (3He) and muons, muonic helium-3 atoms (3Heμ-) are produced and extracted as a beam. As a preliminary step, 4He is irradiated with muons to extract the stopped atoms. The design of the experimental apparatus to extract the stopped atoms could be proceeded. Among the experimental apparatus, improvements associated with the vacuum chamber and its surrounding components were completed. Although the muon beam irradiation that had been planned at Osaka University could not be carried out during the period due to the muon source trouble, we would continue preparations for future achievement.

Free Research Field

ミューオン科学、量子ビーム

Academic Significance and Societal Importance of the Research Achievements

残念ながら照射はビームトラブルで未実施のため、研究としては実施した装置設計、製作、実験検討での成果ではあるが、ビーム生成が可能になった際には学術的意義として運動学的な質量測定で精度向上が考えられる。さらに社会的意義として、ビーム生成手法を応用することで低速ミューオン原子ビームとして材料分析等の応用の可能性について、現段階では検討に至ったので今後の研究継続で明らかにする。