Elucidation of fine structure formation process during magnetic reconnection using ultra-high resolution ion Doppler tomography

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04863
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Plasma science
• Research Institution: The University of Tokyo
• Principal Investigator: Tanabe Hiroshi 東京大学, 大学院新領域創成科学研究科, 助教 (30726013)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: プラズマ・核融合 / 磁気リコネクション / プラズマ診 / コンピュータトモグラフィ / イオン加熱

Outline of Final Research Achievements

This research project experimentally proceeds the investigation of fine structure formation through magnetic reconnection, which is known as the fundamental process of the explosive energy conversion phenomena such as in solar flare, under the influence of guiding field which is perpendicular to reconnection plane. In the merging spherical tokamak formation experiments which utilize reconnection heating, the fine structure was formed when reconnection electric field increases its maximum and it was observed that the structure is impulsively ejected toward downstream when the resistivity reaches the anomalous regime, and it was found that the microscopic localized heating structure around the X-point is finally converted to a global one which surrounds the whole flux surfaces of the two merging plasmas.

Free Research Field

数物系科学(プラズマ科学)

Academic Significance and Societal Importance of the Research Achievements

リコネクション加熱を核融合分野に応用した、世界最大の球状トカマク実験MASTをはじめとした高ガイド磁場実験で観測され、核融合・宇宙・実験室の分野の枠を超えて近年注目されている、X点近傍に現れる微細構造形成メカニズムを明らかにすることに成功した。リコネクション電場の成長とともに、X点近傍に局在化した加熱構造が生成され、高速リコネクションの発現とともにX点近傍にブロブ構造が現れるとともに同構造排出先の合体下流で巨大加熱が得られ、同領域に接続された合体プラズマを覆うグローバルな磁気面上でイオンが加熱されることを解明。核融合プラズマ応用シナリオの開拓として、後者の最適化が重要であることを明らかにした。