Experimental verification of the physics of isotope effects mediated by turbulence nonlinearity

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K03901
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 14020:Nuclear fusion-related
• Research Institution: Kyoto University
• Principal Investigator: OHSHIMA Shinsuke 京都大学, エネルギー理工学研究所, 助教 (00469610)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 水素同位体効果 / プラズマ / 乱流 / 帯状流 / 核融合 / 非線形

Outline of Final Research Achievements

This study elucidates the hydrogen isotope effect on confinement characteristics in magnetic confinement fusion. The research focuses on two main objectives: experimentally observing the nonlinear characteristics of turbulence and verifying the influence of nonlinear turbulence on the isotope effect by controlling the magnetic field configuration. The study manipulates the isotope ratio of hydrogen and deuterium and examines the response of the nonlinear coupling and competition between turbulence and a zonal flow. A combined measurement system is used to directly observe turbulence and a zonal flow, utilizing various fluctuation analysis techniques to evaluate their fundemental and nonlinear characteristics. The study also investigates the impact of the isotope effect by controlling the geometric shape of the magnetic field configuration.

Free Research Field

プラズマ・核融合

Academic Significance and Societal Importance of the Research Achievements

閉じ込め特性に対する“水素同位体効果”は、ITERおよび将来の核融合炉の設計・性能予測の基盤となる知見でありながら、その物理機構は未解明である．本研究は同位体効果は乱流の非線形性を介在して発現しているのか？という疑問に対して取り組む．これは、イオン質量の違いという単純な差異が、なぜ輸送の基礎的理解に反して輸送改善を生み出しうるのか？なぜ磁場配位に応じてその改善度が異なるのか？という，プラズマ・乱流物理を深化させる取り組みであり，この点に学術的意義を有する．同時に、エネルギー問題を決着する可能性のある核融合炉の設計・性能予測に不可欠な基盤的知見に資することから，重要な社会的意義がある．