Verification of role of ion viscosity for a transition to improved confinement mode in helical plasmas

• Project/Area Number: 20860089
• Research Category: Grant-in-Aid for Young Scientists (Start-up)
• Allocation Type: Single-year Grants
• Research Field: Nuclear fusion studies
• Research Institution: National Institute for Fusion Science
• Principal Investigator: TAKAHASHI Hiromi National Institute for Fusion Science, 大型ヘリカル研究部, 助教 (00462193)
• Project Period (FY): 2008 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥3,276,000 (Direct Cost: ¥2,520,000、Indirect Cost: ¥756,000); Fiscal Year 2009: ¥1,547,000 (Direct Cost: ¥1,190,000、Indirect Cost: ¥357,000); Fiscal Year 2008: ¥1,729,000 (Direct Cost: ¥1,330,000、Indirect Cost: ¥399,000)
• Keywords: 核融合 / プラズマ / 磁場閉じ込め / 閉じ込め改善モード / イオン粘性 / ポロイダルフロー / ヘリカル系 / 電極バイアス

Research Abstract

We carried out electrode biasing experiments in the LHD and the Heliotron-J. The transition with the negative plasma resistance was successfully achieved during applying triangular-waveform voltage in ECRH discharges. The improvement of the stored energy, the depression of the density fluctuation and the other phenomena indicating the confinement improvement are observed in the forward transition. The threshold voltage was different between forward transition and backward one and the hysteresis was observed in the voltage-current curve.

Research Products

• [Journal Article] High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University Heliac (2009)
  • Author(s): H. Utoh, 他
  • Journal Title: J. Plasma Fusion Res. SERIES 8 Pages: 1052-1057
  • Peer Reviewed
• [Journal Article] High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University Heliac (2009)
  • Author(s): H.Utoh, et al.
  • Journal Title: J.Plasma Fusion Res.SERIES 8 Pages: 1052-1057
  • Peer Reviewed
• [Journal Article] Study of Ion Viscosity by Spontaneous L-H Transitions under Marginal Hot Cathode Biasing in the Tohoku University Heliac (2008)
  • Author(s): S. Kitajima, H. Takahashi, 他
  • Journal Title: Nuclear Fusion 48 Pages: 35002-35002
  • Peer Reviewed
• [Journal Article] Study of Ion Viscosity by Spontaneous L-H Transitions under Marginal Hot Cathode Biasing in the Tohoku University Heliac (2008)
  • Author(s): S. Kitajima, 他
  • Journal Title: e-Proc. 22th IAEA Fusion Energy Conf. EX/P5-12 Pages: 1-8
  • Peer Reviewed
• [Journal Article] Effects of Rotating Magnetic Islands Driven by External Perturbation Fields in the TU-Heliac (2008)
  • Author(s): S. Kitajima, 他
  • Journal Title: Plasma and Fusion Research 3
  • Peer Reviewed
• [Journal Article] Study of Ion Viscosity by Spontaneous L-H Transitions under Marginal Hot Cathode Biasing in the Tohoku University Heliac (2008)
  • Author(s): S. Kitaiima, H. Takahashi, et al.
  • Journal Title: Nuclear Fusion 48
  • Peer Reviewed
• [Journal Article] Density Collapse in Improved Confinement Mode on Tohoku University Heliac (2008)
  • Author(s): S. Kitajima, et al.
  • Journal Title: e-Proc. 22th IAEA Fusion Energy Conf. EX/P5-12 Pages: 1-8
  • Peer Reviewed
• [Journal Article] Effects of Rotating Magnetic Islands Driven by External Perturibation Fields in the TU-Heliac (2008)
  • Author(s): S. Kitajima, et al.
  • Journal Title: Plasma and Fusion Research 3
  • Peer Reviewed
• [Presentation] ヘリカルプラズマにおける電極バイアスによる閉じ込め遷移に対するリップル構造依存性 (2009)
  • Author(s): 高橋裕己, 他
  • Organizer: プラズマ核融合学会第26回年会
  • Place of Presentation: 京都市国際交流会館
  • Year and Date: 2009-12-03
• [Presentation] Experimental study of flow bifurcation by an electrode biasing in TU-Heliac, CHS and Heliotron J, "12th International Workshop on "H-mode Physics and Transport Barriers" (2009)
  • Author(s): S. Kitajima, H. Takahashi, 他
  • Organizer: USA, Princeton University
  • Place of Presentation: Plasma Physics Laboratory
  • Year and Date: 2009-10-01
• [Presentation] Experimental study of flow bifurcation by an electrode biasing in TU-Heliac, CHS and Heliotron J (2009)
  • Author(s): S.Kitajima, et al
  • Organizer: 12th International Workshop on "H-mode Physics and Transport Barriers"
  • Place of Presentation: USA, Princeton University, Plasma Physics Laboratory
  • Year and Date: 2009-10-01
• [Presentation] 東北大学ヘリアック装置におけるバイアスプラズマ中での密度崩壊と揺動計測 (2009)
  • Author(s): 佐藤淳弥, 他
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 熊本大学黒髪キャンパス
  • Year and Date: 2009-09-27
• [Presentation] High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University (2009)
  • Author(s): H. Utoh, 他
  • Organizer: 14th International Congress on Plasma Physics, Fukuoka
  • Place of Presentation: Fukuoka International Congress Center
  • Year and Date: 2009-09-08
• [Presentation] Study of Transition Mechanism Based on Ion Viscosity by Electrode Biasing in Helical Plasmas (2009)
  • Author(s): H. Takahashi, 他
  • Organizer: 36th European Physical Society Conference on Plasma Physics
  • Place of Presentation: Bulgaria, National Palace of Calture
  • Year and Date: 2009-06-29
• [Presentation] High Beta Discharges with Hydrogen Storage Electrode Biasing in the Tohoku University (2008)
  • Author(s): H. Utoh, et al.
  • Organizer: 14th Internat ional Congress on Plasma Physics
  • Place of Presentation: 福岡国際会議場
• [Remarks]
  • URL: http://www.nifs.ac.jp/phprd/index.html
• [Remarks]
  • URL: http://www.nifs.ac.jp/phprd/index.html