Clarification of dynamic interaction among turbulence, flow, and solitary eddy in a linear magnetized plasma

• Project/Area Number: 17K14897
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: Shimane University (2018-2019); Teikyo University (2017)
• Principal Investigator: Arakawa Hiroyuki 島根大学, 学術研究院理工学系, 准教授 (00615106)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: プラズマ乱流 / 孤立渦 / 帯状流 / プラズマ計測 / レーザー誘起蛍光法 / 乱流輸送 / 飛沫 / プラズマ / 乱流 / 輸送

Outline of Final Research Achievements

In this study, we clarified dynamics among turbulence (drift wave type), flow (zonal flow) and a solitary eddy in a linear magnetized plasma. The solitary eddy is a perturbation with circumnavigating motion localized radially and azimuthally. The solitary eddy is organized/damped in synchronization with the phase modulation of the fundamental drift wave type mode and nonlinearly excited modes. The modes are modulated by the flow fluctuations. In addition, it was observed that a coherent structure with a shorter life and a larger wave number was formed at the formation of the solitary eddy. The amplitudes of particle transport by the solitary eddy and the coherent structure are close, which indicates that the coherent structure would have great impact on the turbulent transport.

Academic Significance and Societal Importance of the Research Achievements

本研究成果による、孤立渦形成機構の解明により、これまで考えられてきた乱流と流れの２体系の乱流物理理論を、孤立渦を加えた３体系に拡張する指標ができた。加えて、孤立渦に伴うコヒーレント構造の観測とこれらの輸送の評価により、４次的効果を含めた多体の乱流物理の重要性を示した。本研究成果を基礎として、核融合プラズマにおいても、閉じ込め改善・新しい制御手法の開発ができる可能性がある。加えて物理的共通点が知られている惑星流体等、中性乱流理論への寄与も期待できる。

Research Products

• [Journal Article] Ion temperature measurement by laser‐induced fluorescence spectroscopy in panta (2019)
  • Author(s): Arakawa Hirotyuki、Inagaki Shigeru、Kosuga Yusuke、Sasaki Makoto、Kin Fumiyoshi、Hasamada Kazunobu、Yamasaki Kotaro、Kobayashi Tatsuya、Yamada Takuma、Nagashima Yoshihiko、Fujisawa Akihide、Kasuya Naohiro、Itoh Kimitaka、Itoh Sanae‐I
  • Journal Title: IEEJ Transactions on Electrical and Electronic Engineering Volume: 14 Issue: 10 Pages: 1450-1454
  • DOI: 10.1002/tee.22962
  • Peer Reviewed / Open Access
• [Journal Article] Roles of solitary eddy and splash in drift wave - zonal flow system in a linear magnetized plasma (2019)
  • Author(s): H. Arakawa, M. Sasaki, S. Inagaki, Y. Kosuga, T. Kobayashi, N. Kasuya, T. Yamada, Y. Nagashima, F. Kin, A. Fujisawa, K. Itoh, and S.-I. Itoh
  • Journal Title: Physics of Plasma Volume: 印刷中
  • Peer Reviewed
• [Presentation] 直線磁化プラズマにおける磁場強度-中性粒子ガス圧制御による帯状流変化 (2020)
  • Author(s): 荒川弘之, 佐々木真, 稲垣滋, 小菅佑輔, 小林達哉, 山田琢磨, 永島芳彦, 藤澤彰英, 伊藤公孝
  • Organizer: 日本物理学会第７５回年次大会
• [Presentation] ベクトルトモグラフィーによる乱流中の準秩序構造観測 (2019)
  • Author(s): 荒川弘之, 佐々木真，稲垣滋，藤澤彰英，寺坂健一郎 ，山崎広太郎
  • Organizer: 第36回 プラズマ・核融合学会 年会
• [Presentation] 直線磁化プラズマにおけるドリフト波・帯状流・孤立渦による飛沫生成機構 (2019)
  • Author(s): 荒川弘之,佐々木真,稲垣滋,小菅佑輔,小林達哉,金史,挾間田一誠,河内裕一,山田琢磨,永島芳彦,山崎広太郎,藤澤彰英,伊藤公孝,伊藤早苗
  • Organizer: 日本物理学会第74回年次大会
• [Presentation] Wave, flow and vortex: the third structure in drift wave turbulence (2018)
  • Author(s): H. Arakawa, S. Inagaki, M. Sasaki, Y. Kosuga, T. Kobayashi, N. Kasuya, Y. Nagashima, T. Yamada, A. Fujisawa, S.-I. Itoh, K. Itoh
  • Organizer: 2nd Asia-Pacific Conference on Plasma Physics
  • Int'l Joint Research / Invited
• [Presentation] Observation of excitation/damping mechanism on solitary eddy in a linear magnetized plasma (2017)
  • Author(s): 荒川弘之,佐々木真,稲垣滋,小菅佑輔,金史良,小林達哉,永島芳彦,山田琢磨,山崎広太郎,藤澤彰英,伊藤早苗,伊藤公孝
  • Organizer: Plasma Conference 2017
• [Presentation] レーザー誘起蛍光法を用いたイオン温度計測のための高速波長スキャン (2017)
  • Author(s): 木村俊介,荒川弘之,稲垣滋,金史良,挾間田一誠,張博宇,山崎広太郎,山田琢磨,永島芳彦,佐々木真,糟谷直宏,小菅佑輔,藤澤彰英
  • Organizer: プラズマ・核融合学会九州・沖縄・山口支部. 第 21 回支部大会