Quantitative evaluation of high Z impurity screening effect in a stochastic magnetic layer and transport model validation

• Project/Area Number: 25420893
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: National Institute for Fusion Science
• Principal Investigator: Kobayashi Masahiro 核融合科学研究所, ヘリカル研究部, 准教授 (30399307)
• Co-Investigator(Renkei-kenkyūsha): MORITA Shigeru 核融合科学研究所, ヘリカル研究部, 教授 (80174423) ; GOTO Motoshi 核融合科学研究所, ヘリカル研究部, 准教授 (00290916) ; KAWAMURA Gakushi 核融合科学研究所, ヘリカル研究部, 助教 (70509520) ; DAI Shuyu 核融合科学研究所, ヘリカル研究部, 特任研究員 (50754686)
• Research Collaborator: FENG Yuehe マックスプランク研究所, 上級研究員 ; Xu Yuhong 西南物理研究所, 西南物理研究所, 教授 ; Dong Chunfeng 西南物理研究所, 准教授 ; SCHMITZ Oliver ウィスコンシン大学, 准教授 ; CORRE Yann カダラッシュ研究所
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2013: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 核融合 / ストキャスティック磁場 / 不純物輸送 / 分光計測 / 数値シミュレーション / 磁場閉じ込め核融合 / 高Z不純物 / 国際研究者交流 / アメリカ：ドイツ / 高Ｚ不純物 / 可視分光計測 / 国際研究者交流 ドイツ、アメリカ

Outline of Final Research Achievements

Transport properties of high Z (high atomic number) impurity in the edge stochastic magnetic layer have been investigated. Following results are obtained: Screening effects have been observed for different impurity species of Z numbers, Z=2, 6 and 26 (helium, carbon and iron). The current transport model needs a cross-field transport coefficient for impurity larger than the background plasma by a factor of 3 to 4. About 10% of first wall source should be considered to interpret the experimental results. Multi-machine comparison shows that the stochastic layer width should be larger than the impurity penetration length by a factor of 10 in order to realize effective impurity screening. Impurity flow velocity parallel to the magnetic field lines has been successfully measured, in which a clear correlation between the flow field and magnetic structure is identified. The result opens further possibility of detailed validation of the current transport model in future.

Research Products

• [Int'l Joint Research] マックスプランク研究所(ドイツ)
• [Int'l Joint Research] 西南物理研究所(中国)
• [Int'l Joint Research] ウィスコンシン大学(アメリカ)
• [Int'l Joint Research] カダラッシュ研究所(フランス)
• [Journal Article] Evaluation of Poloidal Distribution from Edge Impurity Emissions Measured at Different Toroidal Positions in Large Helical Device (2017)
  • Author(s): H.M.Zhang, S.Morita, T.Oishi, M.Kobayashi, M.Goto, X.L.Huang
  • Journal Title: Plasma and Fusion Research Volume: 11 Issue: 0 Pages: 3402038-3402038
  • DOI: 10.1585/pfr.10.3402038
  • NAID: 130005302924
  • ISSN: 1880-6821
  • Year and Date: 2017-01-23
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Dynamics of three-dimensional radiative structures during RMP assisted detached plasmas on the large helical device and its comparison with EMC3-EIRENE modeling (2016)
  • Author(s): Shwetang N. Pandya, Byron J. Peterson, Masahiro Kobayashi, Katsumi Ida, Kiyofumi Mukai, Ryuichi Sano, Junichi Miyazawa, Hirohiko Tanaka, Suguru Masuzaki, Tsuyoshi Akiyama, Gen Motojima, Noriyasu Ohno, LHD Experiment Group
  • Journal Title: Nuclear Fusion Volume: 56 Pages: 046002-046002
  • DOI: 10.1088/0029-5515/56/4/046002
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] EMC3-EIRENE modelling of edge impurity transport in the stochastic layer of the large helical device compared with extreme ultraviolet emission measurements (2016)
  • Author(s): S. Dai, M. Kobayashi, G. Kawamura, S. Morita, H. M. Zhang, T. Oishi, Y. Feng, D. Z. Wang, Y. Suzuki and the LHD Experimental Group
  • Journal Title: Nuclear Fusion Volume: 56 Pages: 066005-066005
  • DOI: 10.1088/0029-5515/56/6/066005
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] EMC3-EIRENE simulation of impurity transport in comparison with EUV emission measurements in the stochastic layer of LHD: Effects of force balance and transport coefficients (2016)
  • Author(s): S. Y. Dai, M. Kobayashi, G. Kawamura, S. Morita, T. Oishi, H. M. Zhang, X. L. Huang, Y. Feng, D. Z. Wang, Y. Suzuki, the LHD experiment group
  • Journal Title: Contributions to Plasma Physics Volume: 印刷中
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Impact of 3D magnetic field structure on boundary and divertor plasmas in stellarator/heliotron devices (2015)
  • Author(s): M. Kobayashi, Y. Feng, Y. Xu, F.L. Tabares, K. Ida, O. Schmitz, T.E. Evans, H. Frerichs, Y. Liang, A. Bader, K. Itoh, H. Yamada, Ph. Ghendrih, G. Ciraolo, D. Tafalla, A. Lopez-Fraguas, H.Y. Guo, Z.Y. Cui, D. Reiter, N. Asakura, U. Wenzel, S. Morita, N. Ohno, B.J. Peterson and S. Masuzaki
  • Journal Title: Journal of Nuclear Materials Volume: 463 Pages: 2-10
  • DOI: 10.1016/j.jnucmat.2015.01.011
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 3D effects of edge magnetic field configuration on divertor/scrape-off layer transport and optimization possibilities for a future reactor (2015)
  • Author(s): M. Kobayashi, Y. Xu, K. Ida, Y. Corre, Y. Feng, O. Schmitz, H. Frerichs, F.L. Tabares, T.E. Evans, J.W. Coenen, Y. Liang, A. Bader, K. Itoh, H. Yamada, Ph. Ghendrih, G. Ciraolo, D. Tafalla, A. Lopez-Fraguas, H.Y. Guo, Z.Y. Cui, D. Reiter, N. Asakura, U. Wenzel, S. Morita, N. Ohno, B.J. Peterson and S. Masuzaki
  • Journal Title: Nuclear Fusion Volume: 55 Pages: 104021-104021
  • DOI: 10.1088/0029-5515/55/10/104021
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of neutral hydrogen on edge impurity behavior in stochastic magnetic field layer of Large Helical Device (2015)
  • Author(s): S.Morita, M.Kobayashi, T.Oishi, H.M.Zhang, M.Goto, Z.Y.Cui, C.F.Dong, L.Q.Hu, X.L.Huang, G.Kawamura, S.Masuzaki, I.Murakami, E.H.Wang
  • Journal Title: Journal of Nuclear Materials Volume: 463 Pages: 644-648
  • DOI: 10.1016/j.jnucmat.2014.12.055
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Benchmark of Monte Carlo Scheme of EMC3 Dealing with Non-Uniform Cross-Field Transport Coefficients and Implementation in LHD (2014)
  • Author(s): M. Kobayashi, Y. Feng, I. Yamada, H. Hayashi, and G. Kawamura
  • Journal Title: Contributions to Plasma Physics Volume: 54 Pages: 383-387
  • DOI: 10.1002/ctpp.201410015
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Impurity shielding criteria for steady state hydrogen plasmas in the LHD, a heliotron-type device (2014)
  • Author(s): Y Nakamura, M Kobayashi, S Yoshimura, N Tamura, M Yoshinuma,K Tanaka, C Suzuki, B J Peterson, R Sakamoto, T Morisaki, the LHD Experiment Group
  • Journal Title: Nuclear Fusion Volume: 56
  • DOI: 10.1088/0741-3335/56/7/075014
  • Peer Reviewed
• [Journal Article] Two-dimensional study of edge impurity transport in the Large Helical Device (2014)
  • Author(s): S.Morita, E.H.Wang, C.F.Dong, T.Oishi, M.Goto, X.L.Huang
  • Journal Title: Plasma Physics and Controlled Fusion Volume: 56
  • DOI: 10.1088/0741-3335/56/9/094007
  • Peer Reviewed
• [Presentation] Relation between hydrogen/impurity emission distributions and stochastic magnetic field structure in LHD (2015)
  • Author(s): 小林政弘、森田繁、後藤基志、佐野竜一、ピーターソン・バイロン、ＬＨＤ実験グループ
  • 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
  • Year and Date: 2015-11-24
• [Presentation] Relation between impurity/hydrogen emissions and edge stochastic magnetic structure at detachment transition observed in LHD divertor region (2015)
  • Author(s): M. Kobayashi, S. Morita, M. Goto, R. Sano, B.J. Peterson, the LHD experiment group
  • Organizer: 20th International Stellarator-Heliotron Workshop
  • Place of Presentation: Greifswald, Germany
  • Year and Date: 2015-10-05
  • Int'l Joint Research
• [Presentation] Effects of stochastic magnetic boundaries on divertor optimizations (2015)
  • Author(s): M. Kobayashi
  • Organizer: 1st IAEA Technical Meeting on Divertor Concepts
  • Place of Presentation: IAEA Headquarters, Vienna, Austria
  • Year and Date: 2015-09-29
  • Int'l Joint Research / Invited
• [Presentation] Transport and exhaust in helical divertors (2015)
  • Author(s): M. Kobayashi, S. Masuzaki, G. Motojima, M. Tokitani, M. Shoji, H. Tanaka, T. Morisaki, the LHD experiment group
  • Organizer: 597th Wilhelm and Else Heraeus Seminar, Stochasticity in Fusion Plasmas
  • Place of Presentation: Physikzentrum Bad Honnef, Germany
  • Year and Date: 2015-09-10
  • Int'l Joint Research / Invited
• [Presentation] 2D visible imaging spectrometer for divertor plasma in LHD (2014)
  • Author(s): 小林政弘、森田繁、後藤基志、LHD実験グループ
  • Organizer: プラズマ・核融合学会第31回年会
  • Place of Presentation: 朱鷺メッセ, 新潟
  • Year and Date: 2014-11-18 – 2014-11-21
• [Presentation] Benchmark of Monte Carlo scheme of EMC3 dealing with non-uniform cross-field transport coefficients and implementation in LHD (2013)
  • Author(s): M. Kobayashi, Y. Feng, I. Yamada, H. Hayashi and G. Kawamura
  • Organizer: 14th International Workshop on Plasma Edge Theory in Fusion Devices
  • Place of Presentation: Cracow, Poland
• [Presentation] LHDにおける周辺部ストキャスティック領域の水素・不純物発光の2次元可視分光計測 (2013)
  • Author(s): 小林政弘、森田繁、後藤基志、LHD実験グループ
  • Organizer: プラズマ・核融合学会 第30回年会
  • Place of Presentation: 東京工業大学 大岡山キャンパス
• [Presentation] Two-dimensional study of edge impurity transport in LHD (2013)
  • Author(s): S.Morita, M.Kobayashi, 他９名
  • Organizer: Joint 19th ISHW and 16th RFP workshop
  • Place of Presentation: Padova, Italy