Studies of the density limit of the lower-hybrid waves with microwave back-scattering

• Project/Area Number: 15K18303
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear fusion studies
• Research Institution: The University of Tokyo
• Principal Investigator: Tsujii Naoto 東京大学, 大学院新領域創成科学研究科, 助教 (20707351)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 核融合 / 球状トカマク / プラズマ / 低域混成波 / マイクロ波診断 / トカマク / マイクロ波散乱計 / 核融合プラズマ / 全波計算

Outline of Final Research Achievements

To investigate the propagation and absorption of lower-hybrid waves in the spherical tokamak plasma, we attempted to developed a microwave scattering diagnostic which can measure small density fluctuations of the lower-hybrid waves. We have newly developed a microwave scattering simulation to analyze the measurement result quantitatively, and to optimize the scattering diagnostic design. We have built two scattering diagnostics which are sensitive to different parameter spaces and attempted to detect LH waves, but we were not able to measure any signal above the noise floor during the project period. We will continue to improve the accuracy of our numerical simulations and develop a microwave diagnostic which can measure LH waves directly.

Research Products

• [Int'l Joint Research] MIT Plasma Science and Fusion Center(米国)
• [Int'l Joint Research] MIT Plasma Science and Fusion Center(米国)
• [Int'l Joint Research] MIT Plasma Science and Fusion Center(米国)
• [Presentation] Fully non-inductive plasma start-up with lower-hybrid waves using the outboard-launch and top-launch antennas on the TST-2 spherical tokamak (2017)
  • Author(s): N. Tsujii, Y. Takase, A. Ejiri, T. Shinya, S. Yajima, H. Yamazaki, H. Togashi, C.P. Moeller, B. Roidl, W. Takahashi, K. Toida, and Y. Yoshida
  • Organizer: 22nd Topical Conference on Radiofrequency Power in Plasmas
  • Int'l Joint Research / Invited
• [Presentation] TST-2における低域混成波計測用マイクロ波散乱計の開発 (2016)
  • Author(s): 辻井 直人、高瀬 雄一、江尻 晶、曽根原 正晃、冨樫 央、矢嶋 悟、吉田 裕亮、高橋 航、戸井田 和哉、山崎 響、北山 明親、佐藤 暁斗、武井 悠稀、田尻 芳之、松本 直希、ROIDL Benedikt
  • Organizer: 第33回 プラズマ・核融合学会 年会
  • Place of Presentation: 東北大学 青葉山キャンパス (宮城県・仙台市)
  • Year and Date: 2016-11-29
• [Presentation] TST-2における低域混成波計測用マイクロ波散乱計の設計 (2016)
  • Author(s): 辻井 直人、高瀬 雄一、江尻 晶、高橋 航、戸井田 和哉、冨樫 央、曽根原 正晃、矢嶋 悟、山崎 響、吉田 裕亮、ROIDL Benedikt
  • Organizer: 第11回 核融合エネルギー連合講演会
  • Place of Presentation: 九州大学 伊都キャンパス (福岡県・福岡市)
  • Year and Date: 2016-07-14
• [Presentation] TST-2におけるマイクロ波後方散乱を用いた低域混成波による非誘導プラズマ立ち上げの研究 (2015)
  • Author(s): 辻井直人、高瀬雄一、江尻晶、古井宏和、本間寛人、中村建大、高橋航、竹内敏洋、冨樫央、戸井田和弥、新屋貴浩、曽根原正晃、矢嶋悟、山﨑響、吉田裕亮
  • Organizer: 第32回プラズマ・核融合学会年会
  • Place of Presentation: 名古屋大学東山キャンパス・豊田講堂 (愛知県・名古屋市)
  • Year and Date: 2015-11-24
• [Presentation] Design of a microwave scattering diagnostic for lower-hybrid waves on TST-2 (2015)
  • Author(s): N. Tsujii, Y. Takase, A. Ejiri, H. Furui, H. Homma, K. Nakamura, W. Takahashi, T. Takeuchi, H. Togashi, K. Toida, T. Shinya, M. Sonehara, S. Yajima, H. Yamazaki and Y. Yoshida
  • Organizer: 57th Annual Meeting of the APS Division of Plasma Physics
  • Place of Presentation: Savannah, Georgia (USA)
  • Year and Date: 2015-11-16
  • Int'l Joint Research
• [Presentation] Measurement of lower-hybrid waves with microwave scattering on TST-2 (2015)
  • Author(s): N. Tsujii, Y. Takase, A. Ejiri, H. Furui, H. Homma, K. Nakamura, W. Takahashi, T. Takeuchi, H. Togashi, K. Toida, T. Shinya, M. Sonehara, S. Yajima, H. Yamazaki and Y. Yoshida
  • Organizer: 18th International Spherical Torus Workshop
  • Place of Presentation: Princeton, New Jersey (USA)
  • Year and Date: 2015-11-03
  • Int'l Joint Research