Realization of Nuclear Spin Relaxation Measurements in Nonmagnetic Nuclei by Negative Muon Spin Injection Method

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K21859
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 13:Condensed matter physics and related fields
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Soshi Takeshita 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 研究機関講師 (40450366)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 負ミュオンスピンインジェクション / 局所磁場 / 分子ダイナミクス

Outline of Final Research Achievements

This research realizes an extremely innovative method (negative muon spin injection method) that enables nuclear spin relaxation measurement in 12C nuclei, which do not have a nuclear spin. This method was applied to ethylene, an organic compound with a simple structure, and polyethylene, a polymer material with simple structure, and it was clarified that the observed local magnetic field can be explained by the dipole interaction between the spin of a single hydrogen nucleus and the spin of a negative muon. Also, it was clarified that the experimental results can be explained by a model in which the carbon bound by the negative muon behaves like a pseudo boron. From the above, this research project has realized nuclear spin relaxation measurement in 12C nuclei, which do not have a nuclear spin.

Free Research Field

量子ビーム

Academic Significance and Societal Importance of the Research Achievements

本研究では、負ミュオンを利用することにより核スピンを持たない12C核のサイトにおいて核スピン緩和測定が可能であることを示した。これは、例えば高分子材料の炭素サイトの情報を得ることができ、またミュオンスピン緩和法に特有のMHz領域の情報が得られるということ示しており、極めて画期的な成果である。