Study of positive muons in metal films at low temperatures

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21867
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 14:Plasma science and related fields
• Research Institution: Tokyo University of Science
• Principal Investigator: Nagashima Yasuyuki 東京理科大学, 理学部第二部物理学科, 教授 (60198322)
• Co-Investigator(Kenkyū-buntansha): 永田 祐吾 東京理科大学, 理学部第二部物理学科, 助教 (30574115)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 正ミュオン / 陽電子 / 電子 / 低温

Outline of Final Research Achievements

Conduction electrons and positrons diffuse efficiently in metal crystals. On the other hand, when positive muons are incident on metals, they do not diffuse efficiently and are bound between lattices. Although positive muons and positrons are both leptons, their behaviors differ greatly. What is the reason? In low-temperature metals, the de Broglie wavelength will be longer than the lattice spacing and positive muons may diffuse as waves rather than as particles. In this research project, we challenged this elucidation.
Although it seemed to be delayed due to the spread of the new coronavirus infection, preparations for the experiment were almost completed by 2020. We plan to conduct experiments at the beam time at JPARC in 2021 and produce results.

Free Research Field

量子ビーム

Academic Significance and Societal Importance of the Research Achievements

本研究課題は、低温の金属中で正ミュオンが効率よく拡散するかどうか調べる。この課題は、金属中における荷電粒子の拡散の本質を突き止める研究である。同時に、低温の金属中で正ミュオンが拡散されることが本当なら、この現象は低速正ミュオンビームを得る方法に利用できるかもしれない。本研究課題は萌芽的な研究ではあるが、成功すれば基礎から応用まで、重要な結果をもたらすものである。