First-principle simulation study of a novel self-heating channel for burning plasmas

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K18341
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: Bierwage Andreas 国立研究開発法人量子科学技術研究開発機構, 六ヶ所核融合研究所 核融合炉システム研究開発部, 上席研究員(定常) (10584691)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 突発的大事象 / 異常自己加熱 / 高エネルギー粒子 / ハイブリッドシミュレーション / ジャイロ運動論的シミュレーション / トカマクプラズマ

Outline of Final Research Achievements

The purpose of this research was to clarify how a recently discovered self-heating channel influences the performance of magnetically confined fusion plasmas. Using a more realistic numerical model of a tokamak plasma, we learned that the originally considered self-heating channel exists only in the magnetohydrodynamic (MHD) description of the plasma. When a more realistic gyrokinetic model is used, the coupling between Alfven waves and ion sound waves effectively vanishes in the high-frequency range of interest. Meanwhile, we have also made two discoveries that motivated us to search for unknown self-heating channels in other directions: (1) We found a new branch of Alvenic waves induced by fast ions. (2) We found that large-amplitude Alfven waves in an MHD-kinetic hybrid simulation give rise to magnetic islands even when the configuration is linearly stable with respect to conventional tearing modes. The underlying physics and practical implications are currently under investigation.

Free Research Field

トカマクプラズマ物理学

Academic Significance and Societal Importance of the Research Achievements

核融合炉を実現するためには効果的な自己加熱機構の存在が重要である。この基礎研究は、以前発見した自己加熱機構の理解を深めるとともに２つの可能性を提示した。この研究成果は、Nature Communicationsに論文発表した。