Investigation of the self-organization during the tokamak startup by means of local helicity injection

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20358
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Nishizawa Takashi 九州大学, 応用力学研究所, 助教 (00955007)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: プラズマ / 自己組織化 / トカマク / トモグラフィ / ガウス過程

Outline of Final Research Achievements

This research aimed at developing the local helicity injection technique to achieve an economical tokamak reactor by removing the central solenoid. While plasma filaments have been successfully injected into a vacuum vessel, the tokamak startup through magnetic helicity injection has not been achieved. Drastic improvements of the plasma gun and the power supply system are necessary. On the other hand, tokamak plasmas have been inductively generated, and a Gaussian-process-based inversion technique has been developed by applying the instruments and skills related to this research project. The research on the helicity injection will be continued for two more years through Grant-in-Aid for Early-Career Scientists. An attempt will be made to achieve the original goal over this period.

Free Research Field

プラズマ・核融合

Academic Significance and Societal Importance of the Research Achievements

局所ヘリシティ入射によるトカマクプラズマの生成という目標は達成できなかったが誘導方式によりトカマクプラズマを立ち上げることに成功した。このプラズマを用いて高温磁化プラズマの研究を開始できるため所属する研究チーム全体として今後プラズマ核融合分野の研究の発展に寄与することが期待される。また自己組織化過程の計測を目的として開発したガウス過程回帰によるトモグラフィ解析手法を干渉計データに応用し電子密度分布およびその微分量を推定することに成功した。この成果は将来の核融合炉内の放射線環境下でのプラズマ内部の実時間モニタリグに活用できる可能性がある。