Pattern formation in plasma turbulence with flows along magnetic field

• Project/Area Number: 18K03578
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 14010:Fundamental plasma-related
• Research Institution: Kyushu University
• Principal Investigator: Kosuga Yusuke 九州大学, 応用力学研究所, 准教授 (00700296)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: プラズマ乱流 / 非線形パターン / 乱流プラズマ / 非線形構造 / 流れ構造 / 旋回度 / 軸方向速度 / プラズマ / 乱流 / 構造形成 / 流れ / パターン形成

Outline of Final Research Achievements

The aim of this study is to elucidate the role of flows along the magnetic field in exciting various secondary structures in plasmas. The previous research reports the modulational instability of perpendicular flows can be controlled by the parallel flows. This study has been extended to the case of spectrum waves, where density modulation has been found to be relevant to excite radial streamer flows. 3D helical flow structures are also excited in turbulent plasmas and the flow helicity can be used to quantify its excitation.

Academic Significance and Societal Importance of the Research Achievements

本研究により乱流プラズマに励起される非線形構造の理解が進んだ。様々な物性をもたらす非線形構造の選択的な励起の問題に取り組み、文脈に応じて輸送を改善もしくは劣化させることが可能となることを示した。核融合プラズマへの応用に着手し、核融合プラズマの性能向上に対して、時には輸送を劣化させるようなことが有効であることをモデルにより示すことができた。

Research Products

• [Journal Article] Numerical investigation on how heat flux avalanche jams trigger the staircase pattern formation (2021)
  • Author(s): Kosuga Y.、Koga D.、Sasaki M.
  • Journal Title: Physics of Plasmas Volume: 28 Issue: 8 Pages: 082302-082302
  • DOI: 10.1063/5.0053919
  • Peer Reviewed / Open Access
• [Journal Article] Minimum enstrophy flows in drift wave turbulence with neutral particles (2020)
  • Author(s): Kosuga Y、Aoki D
  • Journal Title: Plasma Physics and Controlled Fusion Volume: 62 Issue: 10 Pages: 105002-105002
  • DOI: 10.1088/1361-6587/aba73d
  • Peer Reviewed / Open Access
• [Journal Article] Flow helicity of wavy plasma turbulence (2020)
  • Author(s): Kosuga Y.、Sasaki M.、Guo Z. B.
  • Journal Title: Physics of Plasmas Volume: 27 Issue: 2 Pages: 022303-022303
  • DOI: 10.1063/1.5121351
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Scrape-off layer width set by non-linear streamer flows in drift wave turbulence (2020)
  • Author(s): Kosuga Y.、Kin F.、Sasaki M.
  • Journal Title: Contributions to Plasma Physics Volume: - Issue: 5-6
  • DOI: 10.1002/ctpp.201900141
  • Peer Reviewed
• [Journal Article] Role of density modulation in driving nonlinear streamer flows in drift wave turbulence (2018)
  • Author(s): Kosuga Y.、Hasamada K.
  • Journal Title: Physics of Plasmas Volume: 25 Issue: 10 Pages: 100701-100701
  • DOI: 10.1063/1.5049726
  • Peer Reviewed
• [Journal Article] Helical flow structures in torus plasmas (2018)
  • Author(s): Kosuga Y.
  • Journal Title: AIP Conf. Proc. Volume: 1993 Pages: 020009-020009
  • DOI: 10.1063/1.5048719
  • Peer Reviewed / Open Access
• [Presentation] 中性粒子・乱流プラズマ結合系における流れ分布形成過程 (2020)
  • Author(s): 小菅佑輔、青木大輔
  • Organizer: 日本物理学会
• [Presentation] 中性粒子を含むドリフト波乱流における最小エンストロフィー流 (2020)
  • Author(s): 小菅佑輔、青木大輔
  • Organizer: プラズマ核融合学会
• [Presentation] Selectively exciting nonlinear streamer flows in drift wave turbulence (2019)
  • Author(s): Y. Kosuga, F. Kin, M. Sasaki
  • Organizer: 17th International Workshop on Plasma Edge Theory in Fusion Devices
  • Int'l Joint Research
• [Presentation] Flow helicity: could it be useful for fusion? (2019)
  • Author(s): Y. Kosuga
  • Organizer: The 10th Festival de Theorie
  • Int'l Joint Research / Invited
• [Presentation] Generation of helical flow structure in turbulent plasmas and its helicity (2019)
  • Author(s): Y. Kosuga, M. Sasaki, Z.B. Guo
  • Organizer: 日本物理学会年次大会
• [Presentation] Revisiting the excitation of radially elongated convective cells in drift wave turbulence (2018)
  • Author(s): Y. Kosuga and K. Hasamada
  • Organizer: 19th International Congress on Plasma Physics
  • Int'l Joint Research
• [Presentation] How pattern is selected in drift wave turbulence: role of parallel flow shear (2018)
  • Author(s): Y. Kosuga
  • Organizer: 2nd Asia-Pacific Conference on Plasma Physics
  • Int'l Joint Research / Invited