Expermental study on MHD effect of liqid metal free-surface vertical flow for liquid metal divertor

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H06140
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Nuclear fusion studies
• Research Institution: National Institute for Fusion Science
• Principal Investigator: Takuya Goto 核融合科学研究所, ヘリカル研究部, 助教 (30509518)
• Research Collaborator: MIYAZAWA Junichi ; OHGO Takeru
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 液体金属 / 自由表面鉛直流 / MHD効果

Outline of Final Research Achievements

The purpose of this study is experimental examination of the behavior of liquid metal jets by MHD(magnetohydrodynamics) effect when the electric current flows along the jet in the presence of an external magnetic field.
The experiment showed the following three facts. Liquid metal jets can be stabilized by inserting an internal flow resistance as shown in the prior experiment using a water jet. Liquid metal jets deformed with the internal flow resistance in the presence of the MHD effect. The deformation of the jet can be calculated by the Lorentz force that works on the jet when it is regarded as a single conductor.
These results give a design guideline for the divertor, the component of a fusion reactor that accommodates ultra high heat load in steady state to remove impurities from the core plasma, using a liquid metal jet.

Free Research Field

核融合工学

Academic Significance and Societal Importance of the Research Achievements

液体金属噴流のMHD効果に関する研究は過去にも多く行われているが、噴流の安定化のために内挿物を挿入した液体金属噴流に対するMHD効果を初めて実験的に検証した点が本研究の学術的な意義である。また、本研究の結果液体金属噴流を核融合炉のダイバータとして直接適用することは難しいことが判明したが、ダイバータ設計に関する定量的な指針が得られ、またMHD効果が大きく働かない環境における超高熱負荷への対処が可能なシステムの一例を構築することができた。これらが本研究の社会的な意義と言える。