Analysis of global transport of internal transport barrier in tokamak plasmas

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K14446
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 14020:Nuclear fusion-related
• Research Institution: Kyoto University (2022); National Institutes for Quantum Science and Technology (2020-2021)
• Principal Investigator: Kin Fumiyoshi 京都大学, エネルギー理工学研究所, 助教 (40846747)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: プラズマ乱流輸送 / 内部輸送障壁 / 非局所的輸送 / トカマクプラズマ / 雪崩輸送 / 径電場ダイナミクス / 過渡応答解析 / ニューラルネットワーク

Outline of Final Research Achievements

The objective of this study was to investigate the origin of global response of Internal Transport Barrier (ITB) in Tokamak plasma and understand the formation mechanism of ITB. In order to verify core plasma transport and ITB formation, a comparison of the dynamics of heat flux and radial electric field was conducted during both ITB formation and non-formation conditions. The research yielded the following results: (1) dynamics of ITB formation in steady-state negative magnetic shear plasma, (2) global transient response of ITB against cold pulse, (3) development of a neural network-based analysis method for high time-resolution measurement of radial electric field, (4) occurrence of avalanching transport associated with bursty fluctuations and its impact on stiff profiles, and (5) influence of avalanching transport on radial electric field and ITB formation.

Free Research Field

プラズマ物理

Academic Significance and Societal Importance of the Research Achievements

本研究により、トカマクプラズマにおける内部輸送障壁(ITB)の形成機構についての理解が大幅に進展した。大域的輸送がITBに与える影響は著しく、理論モデルの検証や改善に重要な発見となった。また、ITBは高温プラズマの乱流輸送を抑制し、プラズマの性能向上に重要な役割を果たす。ITB形成機構の解明は、トカマクプラズマの制御技術や将来の核融合エネルギー利用に関する基礎物理の構築に大きく貢献する。