パルス高出力リコネクション加熱を用いたトカマク点火実験

2016 Fiscal Year Research-status Report

• Project/Area Number: 15K14279
• Research Institution: The University of Tokyo
• Principal Investigator: 小野 靖 東京大学, 大学院新領域創成科学研究科, 教授 (30214191)
• Co-Investigator(Kenkyū-buntansha): 井 通暁 東京大学, 大学院新領域創成科学研究科, 准教授 (00324799) ; 田辺 博士 東京大学, 大学院新領域創成科学研究科, 助教 (30726013)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 磁気リコネクション / プラズマ合体 / イオン加熱 / 球状トカマク / アルファ加熱 / アウトフロー / ショック / 電子加熱

Outline of Annual Research Achievements

次年度は，計画通りこれまで建設した電源・コイルのインフラをさらに高エネルギー化し，電源系も所有の16kV, 0.4MJに加え，40kV, 20kV, 10kVの合計1MJのコンデンサーを他機関から取得し，総エネルギー1.4MJのシステムを自作した。ポロイダルコイル6基もケーブル巻線製から銅ロッド製に組み直し，力学性能が格段に向上した。トロイダルコイルも強化，平衡磁場コイル電源も高エネルギー密度の電気二重層型コンデンサーを採用・自作し，計測系整備も，従来7×5点の2次元計測であったイオン温度計測を32×10点に高精細化するなど，大きな進歩があった。
インフラを利用して合体させる球状トカマクのポロイダル磁場を徐々に引き上げた結果，ホール効果により，リコネクションアウトフローが傾いてＸ点下流の強いイオン加熱領域が傾く効果やX点に強くピークした電子加熱領域が次々明らかになった。磁場２乗の加熱スケーリングの立証は250eVまで完成している。
リコネクション加熱のみを用いた核融合炉の点火の可能性は内外の注目を集め，2016年10月には日本政府主催のInternational Cool Earth Forum会議に初めて設置された核融合セッションを任されて，招待講演を行ない，IAEA Fusion Energy会議への日本代表論文への採択も3件に達した他，多くの招待講演につながり，高い評価を得ることができた。磁気リコネクションの中心会議であるMR2017国際会議も主催し，盛況であった。
さらに，リコネクション加熱による核融合炉点火のアイデアは英国のベンチャー企業Tokamak Energy社が数億円をかける次期プロジェクトST-40実験に採用され，東京大学が協力して実験をプラン・技術支援し，キーとなるイオン温度計測も東京大学が担当することになるなど実用化に向けて新しい展開につながった。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

予算が少ない中，自作により電源拡張は更に進み，計画を大幅に上まわる1.4MJのコンデンサー電源を整備できたこと，ポロイダルコイル６基すべてを銅ロッドで再構成し，力学強度を大幅に強化したこと，320チャンネルを越えたイオン温度計測システムの構築は計画を上まわる進展である。
特にリコネクション加熱のみを用いた核融合炉の点火の可能性は内外の注目を集め，2016年10月には日本政府主催のInternational Cool Earth Forum会議に初めて開催された核融合セッションを小野が任され，招待講演を行った点は特筆できる。招待講演も９件，IAEA Fusion Energy会議への日本代表論文への採択も3件に達し，2件の新聞発表にもつながり，高い評価を得ることができた。学会での注目度の高さが契機となってリコネクション分野の中心となるMR国際会議を2017年3月に東京大学で主催することにつながり，ここでも90名の参加者を集めて，大きな成果をあげている。リコネクション加熱による核融合点火のアイデアが英国のベンチャー企業Tokamak Energy社が数億円をかける次期プロジェクトST-40実験に採用され，東京大学が技術支援することになった点も特筆できる。
以上，リコネクション加熱による核融合炉点火研究は当初計画になかった大きな進展が複数あり，計画を越える高エネルギーの電源，コイルインフラの完成や高精細イオン温度計測システムの構築とともに，計画以上の成果につながったと判断できる。

Strategy for Future Research Activity

合体実験の高磁場化と2次元計測のインフラを作ってきた結果，計画を上まわる1.4MJのコンデンサー電源と銅ロッド製ポロイダルコイルに320チャンネルドップラー計測を整備できたので，一連の装置の安全を慎重に確認しつつ，徐々にポロイダル磁場を従来の0.02Tから上げており，イオン温度も100eV超へ上昇している。昨年度，高精細化を進めて320から500チャンネルに達しつつある2次元高精細イオンドップラー計測に目処がついたので，今後はこれを基幹計測として用い，ポロイダル磁場を徐々に引き上げつつ，イオン加熱のスケーリングをTS-3球状トカマク実験でこれまでに立証できた250eVを上まわる領域へ拡大していく予定である。また，本研究のリコネクション加熱による核融合点火のアイデアが英国のベンチャー企業Tokamak Energy社の資金量豊富なST-40実験に採用され，東京大学が協力することになったことから，こちらも並行して進めていく予定である。

Research Products

• [Int'l Joint Research] プリンストン大学/プリンストンプラズマ物理研究所(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: プリンストン大学/プリンストンプラズマ物理研究所
• [Int'l Joint Research] カラム研究所/トカマクエナジー研究所(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: カラム研究所/トカマクエナジー研究所
• [Int'l Joint Research] 国立成功大学(台湾)
  • Country Name: その他の国・地域
  • Counterpart Institution: 国立成功大学
• [Journal Article] Localized electron heating during magnetic reconnection in MAST (2017)
  • Author(s): T. Yamada, H. Tanabe, T. G. Watanabe, Y. Hayashi, R. Imazawa, M.Inomoto, Y. Ono, M. Gryaznevich, R. Scannell, C. Michael and The MAST Team
  • Journal Title: Nuclear Fusion Volume: 56 Pages: 106019
  • DOI: 10.1088/0029-5515/56/10/106019
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Energy Conversion Mechanism for Electron Perpendicular Energy (2017)
  • Author(s): X. Guo, R. Horiuchi, C. Z. Cheng, Y. Kaminou and Y. Ono
  • Journal Title: Physics of Plasmas Volume: 24 Pages: 032901
  • DOI: 10.1063/1.4977908
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Investigation of Merging/reconnection Heating during Solenoid-free Startup of Plasmas in the MAST Spherical Tokamak (2017)
  • Author(s): H. Tanabe, T. Yamada, K. Gi, T. Watanabe, M. Inomoto, R. Imazawa, M. Gryaznevich, R. Scannell, N. Conway, C. Michael, B. Crowley, I. Fitzgerald, A. Meakins, N. Hawkes, K. McClements, J. Harrison, T. O'Gorman, C. Z. Cheng, Y. Ono
  • Journal Title: Nuclear Fusion Volume: 57 Pages: 056037
  • DOI: 10.1088/1741-4326/aa6608
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Recent progress of magnetic reconnection research in the MAST spherical tokamak (Invited) (2017)
  • Author(s): H. Tanabe, T. Yamada , T. Watanabe , K. Gi , M. Inomoto , R. Imazawa , M. Gryaznevich , C. Michael , B. Crowley , N. J. Conway , R. Scannell , J. R. Harrison , I. Fitzgerald , A. Meakins , N. C. Hawkes , K. G. McClements , T, O Gorman , C,Z. (Frank) Cheng , Y. Ono , the MAST team
  • Journal Title: Physics of Plasmas Volume: 24 Pages: 056108
  • DOI: 10.1063/1.4977922
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Numerical study of Hall effects on counter-helicity spheromak merging by twodimensional Hall-MHD simulations (2017)
  • Author(s): Yasuhiro Kaminou, Xuehan Guo, Michiaki Inomoto, Yasushi Ono, and Ritoku Horiuchi
  • Journal Title: Physics of Plasmas Volume: 24 Pages: 032508
  • DOI: 10.1063/1.4978785
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Application of Tomographic Ion Doppler Spectroscopy to Merging Plasma Startup in the MAST Spherical Tokamak (Invited) (2016)
  • Author(s): H. Tanabe, T. Yamada, T. Watanabe, K. Gi, K. Kadowaki, M. Inomoto, R. Imazawa, M. Gryaznevich, R. Scannell, N. J. Conway, B. Crowley, K. G. McClements, I. Fitzgerald, C. Michael, J. Harrison, A. Meakins, N. Hawkes, T. O’Gorman, C. Z. Cheng, Y. Ono, and the MAST Team
  • Journal Title: Plasma and Fusion Research Volume: 11 Pages: 1302093
  • DOI: 10.1585/pfr.11.1302093
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Reconnection Heating Experiments and Simulations for Torus Plasma Merging Startup (2016)
  • Author(s): Y. Ono, T. Yamada, S. Inoue, M. Inomoto, C. Z. Cheng, M. Gryaznavich, R. Scannell, N. J. Conway, B. Crowley, C. Michael, H. Hara, S. Usami and R. Horiuchi
  • Journal Title: Fusion Energy 2016 Volume: 1 Pages: EX/P4-38 (8pp)
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Investigation of Merging/reconnection Heating during Solenoid-free Startup of Plasmas in the MAST Spherical Tokamak (2016)
  • Author(s): H. Tanabe, T. Yamada, K. Gi, T. Watanabe, K. Kadowaki, M. Gryaznevich, R. Scannell, N. J. Conway, C. Michael, B. Crowley, J. Harrison, I. Fitzgerald, A. Meakins, N. Hawkes, K. G. McClements, T. O’Gorman, C. Z. Cheng and the MAST team
  • Journal Title: Fusion Energy 2016 Volume: 1 Pages: EX/P4-32 (8pp)
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Fine structure formation of high field reconnection experiment in MAST and Univ. Tokyo (invited (2017)
  • Author(s): H. Tanabe, T. Yamada, T. Watanabe, K. Gi, H. Koike, A. Kuwahata, H. Yamanaka, K. Kimura, M. Narita, M. Inomoto, R. Imazawa, M. Gryaznevich, R. Scannell, N. Conway, T. O'Gorman, K. G. McClements, C. Z. Cheng, Y. Ono and the MAST team)
  • Organizer: MR2017 Conference (US-Japan workshops and schools on magnetic reconnection)
  • Place of Presentation: ひめぎんホール, 松山，愛媛
  • Year and Date: 2017-03-19 – 2017-03-23
  • Int'l Joint Research / Invited
• [Presentation] High Power Heating of Magnetic Reconnection in TS, MAST and ST-40 Experiments (2017)
  • Author(s): Y. Ono, H. Tanabe, S. Inoue, K. Gi, X. Guo, R. Horiuchi, S. Usami, C.Z. Cheng, M. Gryaznevich
  • Organizer: MR2017 Conference (US-Japan workshops and schools on magnetic reconnection)
  • Place of Presentation: ひめぎんホール, 松山，愛媛
  • Year and Date: 2017-03-19 – 2017-03-23
  • Int'l Joint Research / Invited
• [Presentation] Role of Parallel Electric Field in Collisionless Reconnection (2017)
  • Author(s): C. Z. Chneg, S. Inoue, Y. Ono, R. Horiuchi
  • Organizer: MR2017 Conference (US-Japan workshops and schools on magnetic reconnection)
  • Place of Presentation: ひめぎんホール, 松山，愛媛
  • Year and Date: 2017-03-19 – 2017-03-23
  • Int'l Joint Research / Invited
• [Presentation] An optical probe for local 3D ion flow measurement system (2017)
  • Author(s): Hideya Koike, Hiroshi Tanabe, Ono Yasushi
  • Organizer: MR2017 Conference (US-Japan workshops and schools on magnetic reconnection)
  • Place of Presentation: ひめぎんホール, 松山，愛媛
  • Year and Date: 2017-03-19 – 2017-03-23
  • Int'l Joint Research
• [Presentation] Development of High-Field ST Merging Experiment: TS-U for High Power Reconnection Heating (2016)
  • Author(s): Y. Ono, H. Koike, Tanabe, S. Himeno, S. Ishida, K. Kimura, M. Kawanami, M. Narita, Y. Takahata, T. Yokoyama, M. Inomoto, C. Z. Cheng
  • Organizer: 58th Annual Meeting of the APS Division of Plasma Physics
  • Place of Presentation: San Jose, CA, USA
  • Year and Date: 2016-10-31 – 2016-11-04
  • Int'l Joint Research
• [Presentation] Effects of guide field in driven magnetic reconnection (2016)
  • Author(s): C. Z. Cheng, S. Inoue, R. Horiuchi, Y. Ono, X. Guo
  • Organizer: 58th Annual Meeting of the APS Division of Plasma Physics
  • Place of Presentation: San Jose, CA, USA
  • Year and Date: 2016-10-31 – 2016-11-04
  • Int'l Joint Research
• [Presentation] Energy Conversion Mechanism for Electron Perpendicular Energy in High Guide-Field Reconnection (2016)
  • Author(s): X. Guo, R. Horiuchi, Y. Kaminou, C. Z. Cheng, Y. Ono
  • Organizer: 58th Annual Meeting of the APS Division of Plasma Physics
  • Place of Presentation: San Jose, CA, USA
  • Year and Date: 2016-10-31 – 2016-11-04
  • Int'l Joint Research
• [Presentation] Recent progress of magnetic reconnection research in the MAST spherical tokamak (Invited) (2016)
  • Author(s): Hiroshi Tanabe
  • Organizer: 58th Annual Meeting of the APS Division of Plasma Physics
  • Place of Presentation: San Jose, CA, USA
  • Year and Date: 2016-10-31 – 2016-11-04
  • Int'l Joint Research / Invited
• [Presentation] Reconnection Heating Experiments and Simulations for Torus Plasma Merging Startup (2016)
  • Author(s): Y. Ono, T. Yamada, S. Inoue, M. Inomoto, C. Z. Cheng, M. Gryaznavich, R. Scannell, N. J. Conway, B. Crowley, C. Michael, H. Hara, S. Usami and R. Horiuchi
  • Organizer: Fusion Energy Conference 2016
  • Place of Presentation: Kyoto Convension Center, Kyoto, Kyoro
  • Year and Date: 2016-10-17 – 2016-10-22
  • Int'l Joint Research
• [Presentation] Reconnection Heating Experiments and Simulations for Torus Plasma Merging Startup (2016)
  • Author(s): H. Tanabe, T. Yamada, K. Gi, K. Kadowaki, M. Gryaznavich, R. Scannell, N. J. Conway, C. Michael, B. Crowley, J. Harrison, I. Fitzgerald, A. Meakings, N. Hawkins, K. Mcclrmrntd, T. O’gorman and C. Z. Cheng
  • Organizer: Fusion Energy Conference 2016
  • Place of Presentation: Kyoto Convension Center, Kyoto, Kyoto
  • Year and Date: 2016-10-17 – 2016-10-22
  • Int'l Joint Research
• [Presentation] Formation of Closed Flux Surfaces in Reconnection Current Layer by Accelerated Electrons during Merging Start-up of Spherical Tokamak (2016)
  • Author(s): M. Inomoto, K. Yamasaki, T. Ushika, X. Guo, S. Kamio, R. Yanai, T. Suhawara, Y. Fukai, H. Yamanaka, and R. Tamura
  • Organizer: Fusion Energy Conference 2016
  • Place of Presentation: Kyoto Convension Center, Kyoto, Kyoto
  • Year and Date: 2016-10-17 – 2016-10-22
  • Int'l Joint Research
• [Presentation] Innovative Approaches to Economical DEMO reactors (invited) (2016)
  • Author(s): Yasushi Ono
  • Organizer: 3rd Annal Meeting of Innovation for Cool Earth Forum, Concurrent Session Part 2 “Nuclear Fusion”
  • Place of Presentation: Chinzanso, Tokyo Japan
  • Year and Date: 2016-10-05 – 2016-10-06
  • Int'l Joint Research / Invited
• [Presentation] Merging/ Reconnection Heating for Direct Access to Fusion Reaction (invited) (2016)
  • Author(s): Yasushi Ono and Anthony Ford
  • Organizer: 3rd Annal Meeting of Innovation for Cool Earth Forum, Concurrent Session Part 2 “Nuclear Fusion”
  • Place of Presentation: Chinzanso, Tokyo Japan
  • Year and Date: 2016-10-05 – 2016-10-06
  • Int'l Joint Research / Invited
• [Presentation] Development of High Magnetic Field Merging Tokamak Experiment TS-U for Reconnection Heating Physics and Applications (2016)
  • Author(s): Yasushi Ono, Hiroshi Tanabe, Kokoro Kimura, Masashi Kawanami, Syunsuke Ishida, Ryoma Nakai, Michiaki Inomoto, Chio Zong Cheng
  • Organizer: The 18th International Congress on Plasma Physics (ICPP 2016)
  • Place of Presentation: Kaohsiung Exhibition Center in Kaohsiung, Taiwan
  • Year and Date: 2016-06-27 – 2016-07-01
  • Int'l Joint Research / Invited
• [Presentation] High Power Heating of Magnetic Reconnection in Toroidal Plasma Merging Experiments: TS-3, TS- 4, UTST and MAST (2016)
  • Author(s): H. Tanabe, T. Yamada, R. Imazawa, M. Gryaznevich, R. Scannell, N. Conway, B. Crowley, C. Michael, K. G. McClements, M. Inomoto, C. Z. Cheng, Y. Ono and the MAST team
  • Organizer: The 18th International Congress on Plasma Physics (ICPP 2016)
  • Place of Presentation: Kaohsiung Exhibition Center in Kaohsiung, Taiwan
  • Year and Date: 2016-06-27 – 2016-07-01
  • Int'l Joint Research / Invited
• [Presentation] Shape Reconstruction of Merging Spherical Tokamak Plasma using only based on the External Magnetic Sensor Signals in UTST device (2016)
  • Author(s): T. Ushiki, M. Itagaki, M. Inomoto
  • Organizer: The 18th International Congress on Plasma Physics (ICPP 2016)
  • Place of Presentation: Kaohsiung Exhibition Center in Kaohsiung, Taiwan
  • Year and Date: 2016-06-27 – 2016-07-01
  • Int'l Joint Research
• [Presentation] Electron heating and acceleration during high guide-field magnetic reconnection (2016)
  • Author(s): Xuehan Guo, Chio Z. Cheng, Ritoku Horiuchi, Yasushi Ono
  • Organizer: The 18th International Congress on Plasma Physics (ICPP 2016)
  • Place of Presentation: Kaohsiung Exhibition Center in Kaohsiung, Taiwan
  • Year and Date: 2016-06-27 – 2016-07-01
  • Int'l Joint Research
• [Presentation] Laboratory Experiments of Merging Tokamaks and Spheromaks for Reconnection-Heating Physics and Applications (Invited) (2016)
  • Author(s): Yasushi Ono, Hiroshi Tanabe, Kokoro Kimura, Masashi Kawanami, Syunsuke Ishida, Ryoma Nakai, Michiaki Inomoto, Chio Zong Cheng
  • Organizer: Korean Physical Society
  • Place of Presentation: Daejeon Convention Center, Daejeon, Korea
  • Year and Date: 2016-04-20 – 2016-04-22
  • Int'l Joint Research / Invited
• [Book] The Physics of Plasma-Driven Accelerators and Accelerator-Driven Fusion (2016)
  • Author(s): Toshiki Tajima, Michl Binderbauer, Y. Ono et al.
  • Total Pages: 196
  • Publisher: AIP Publishing
• [Funded Workshop] MR2017 Conference (US-Japan workshops and schools on magnetic reconnection) (2017)
  • Place of Presentation: ひめぎんホール, 松山，愛媛
  • Year and Date: 2017-03-19 – 2017-03-23