Physical Mechanism of Self-Organization in Magnetospheric Plasmas: Focusing on Heat and Particle Transport

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K13525
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 14020:Nuclear fusion-related
• Research Institution: National Institute for Fusion Science (2020-2022); The University of Tokyo (2018-2019)
• Principal Investigator: Kenmochi Naoki 核融合科学研究所, ヘリカル研究部, 助教 (80781319)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 磁気圏型プラズマ / 自己組織化 / 熱・粒子輸送 / 核融合 / トムソン散乱計測 / 深層学習

Outline of Final Research Achievements

The purpose of this study is to clarify the thermal and particle characteristics of spontaneously formed high-beta plasma using the RT-1 device in order to investigate the mechanism of spontaneous confinement of high-beta plasma in the celestial magnetosphere. This study provides two new findings on the mechanism of inward diffusion as follows. (i) Detailed visualization of the peaked density profiles spontaneously formed by inward diffusion was achieved by the detailed measurement and analysis method developed in this study. (ii) We found that low-frequency fluctuations are excited when the peaked density profile is reconstructed by neutral gas injection during the discharge, and detailed measurements of the spatiotemporal structure of the fluctuations suggest that the mechanism of inward diffusion is related to drift wave instability.

Free Research Field

プラズマ物理

Academic Significance and Societal Importance of the Research Achievements

本論文で明らかにした密度分布の自己調整機構は、定常閉じ込め系に共通する長寿命構造の基礎物理における知見を与えることができる。トカマク等の磁場配位とは異なる新概念核融合装置の研究としてはもとより、将来の核融合装置に共通の物理工学課題も含んでおり、高性能な高ベータプラズマ生成とプラズマ閉じ込め物理研究の進展が期待できる。