Updated on 2024/07/28

Information

 

写真a

 
ONCHI TAKUMI
 
Organization
Research Institute for Applied Mechanics Advanced Fusion Research Center Assistant Professor
Interdisciplinary Graduate School of Engineering Sciences Department of Interdisciplinary Engineering Sciences(Joint Appointment)
Title
Assistant Professor
Contact information
メールアドレス
Tel
0925837696
Profile
九州大学の球状トカマクQUESTにおいて実験研究を行っている. 主な研究テーマは「電子サイクロトロン加熱・電流駆動」. QUESTでは「プラズマ電流スタートアップ」や「同軸ヘリシティ入射」で共同研究を受け入れている. 複雑系が持つ順列エントロピーと統計的複雑性を調べる研究も実施中.
Homepage

Degree

  • Ph.D

Research History

  • University of Saskatchewan

Research Interests・Research Keywords

  • Research theme:Permutation entropy and statistical complexity of time series data in plasma experiment

    Keyword:Permutation entropy, statistical complexity

    Research period: 2017.1 - 2025.3

  • Research theme:Power electronics for Tokamak Ohmic heating

    Keyword:High voltage power supply, power electronics, Tokamak

    Research period: 2016.4 - 2025.3

  • Research theme:Electron cyclotron heating/current-drive on QUEST spherical tokamak

    Keyword:Plasma, Spherical tokamak, RF plasma heating/current-drive

    Research period: 2015.4 - 2025.3

Awards

  • プラズマ・核融合学会第27回技術進歩賞

    2022.9   プラズマ・核融合学会   先進核融合装置プラズマ加熱用低周波数ジャイロトロンの開発研究

Papers

  • Non-inductive plasma current ramp-up through oblique injection of harmonic electron cyclotron waves on the QUEST spherical tokamak Reviewed International journal

    Onchi, T.; Idei, H.; Fukuyama, M.; Ogata, D.; Ashida, R.; Kariya, T.; Ejiri, A.; Matsuzaki, K.; Osawa, Y.; Peng, Y.; Kojima, S.; Watanabe, O.; Hasegawa, M.; Nakamura, K.; Kuroda, K.; Ikezoe, R.; Ido, T.; Hanada, K.; Bertelli, N.; Ono, M.; Fukuyama, A.

    PHYSICS OF PLASMAS   28 ( 2 )   022505   2021.2

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1063/5.0031357

  • Permutation entropy and statistical complexity in characterising low-aspect-ratio reversed-field pinch plasma Reviewed International journal

    T. Onchi, A. Fujisawa, A. Sanpei, H. Himura, S. Masamune, and RELAX team

    Physica Scripta   92 ( 5 )   055601   2017.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: https://doi.org/10.1088/1402-4896/aa6689

  • Development Toward a Repetitive Compact Torus Injector Reviewed International journal

    Takumi Onchi, D. McColl, A. Rohollahi, C. Xiao, A. Hirose, M. Dreval, S. Wolfe

    IEEE Transactions on Plasma Science   44 ( 2 )   2016.2

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  • Effects of compact torus injection on toroidal flow in the STOR-M tokamak Reviewed International journal

    T. Onchi, Y. Liu, M. Dreval, D. McColl, S. Elgriw, D. Liu, T. Asai, C. Xiao, A. Hirose

    Plasma Physics and Controlled Fusion   55 ( 3 )   2013.3

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  • Tangential soft-x ray imaging for three-dimensional structural studies in a reversed field pinch Reviewed International journal

    T. Onchi, R. Ikezoe, K. Oki, A. Sanpei, H. Himura, S. Masamune

    Review of Scientific Instruments   81 ( 7 )   2010.7

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  • Hydrogen removal by electron cyclotron wall conditioning with neon gas and its impact of tokamak plasma start-up on the QUEST spherical tokamak Reviewed International journal

    Masakatsu Fukumoto, Qilin Yue, Kazuaki Hanada, Shinichiro Kojima, Tomohide Nakano, NY Yoshida, Ryuya Ikezoe, Yoshihiko Nagashima, Takeshi Ido, Takumi Onchi, Hiroshi Idei, Hiroki Iguchi, Takumi Komiyama, Taiichi Shikama, Akira Ejiri, Suguru Masuzaki, Mizuki Sakamoto, Yoshio Ueda, Kengoh Kuroda, Kaori Kono, Shun Shimabukuro, Aki Higashijima

    Nuclear Fusion   64 ( 6 )   066022   2024.5

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  • Comparison of electron temperature and density measured by helium line intensity ratio and Thomson scattering methods in ECH spherical tokamak plasma Authors Reviewed International journal

    Takumi Komiyama, Taiichi Shikama, Kazuaki Hanada, Takeshi Ido, Takumi Onchi, Kaori Kono, Akira Ejiri, Makoto Hasegawa, Satoshi Inoue, Masahiro Hasuo, Hiroshi Idei, Qilin Yue, Kengoh Kuroda, Aki Higashijima, Pakkapawn Prapan

    Plasma Physics and Controlled Fusion   66   045018   2024.3

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  • Demonstration of transient CHI startup using a floating biased electrode configuration Reviewed International journal

    Kengoh Kuroda, R Raman, T Onchi, M Hasegawa, K Hanada, M Ono, BA Nelson, J Rogers, R Ikezoe, H Idei, T Ido, M Nagata, O Mitarai, N Nishino, Y Otsuka, Y Zhang, K Kono, S Kawasaki, T Nagata, A Higashijima, S Shimabukuro, I Niiya, I Sekiya, K Nakamura, Y Takase, A Ejiri, S Murakami

    Nuclear Fusion   64 ( 1 )   014002   2023.12

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  • Effects of toroidally-distributed-divertor biasing on scrape-off-layer (SOL) current drive, divertor particle flux and fast electron confinement in the QUEST spherical tokamak Reviewed International journal

    Kazuo Toi, Takumi Onchi, Hideki Zushi, Kengoh Kuroda, Hiroshi Idei, Kazuaki Hanada, Makoto Hasegawa, Shinichiro Kojima, Ryuya Ikezoe, Takeshi Ido, Shoji Kawasaki, Aki Higashijima, QUEST Experiment Group

    Nuclear Fusion   63 ( 10 )   106018   2023.9

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  • Sudden Change Events of Plasma Current during Electron-Cyclotron Current Start-Up on the QUEST Spherical Tokamak Reviewed International journal

    Ryuya Ikezoe, Kosuke Takeda, Kengoh Kuroda, Takumi Onchi, Takahiro Nagata, Izumi Sekiya, Hiroshi Idei, Fadilla Zennifa, Yifan Zhang, Seiya Sakai, Rikuya Miyata, Takahiro Yamaguchi, Makoto Hasegawa, Yoshihiko Nagashima, Takeshi Ido, Kazuaki Hanada

    Plasma and Fusion Research   18   2402066 - 2402066   2023.8

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  • Spectroscopic measurement of increases in hydrogen molecular rotational temperature with plasma-facing surface temperature and due to collisional-radiative processes in tokamaks Invited Reviewed International journal

    N Yoneda, T Shikama, F Scotti, K Hanada, H Iguchi, H Idei, T Onchi, A Ejiri, T Ido, K Kono, Y Peng, Y Osawa, G Yatomi, A Kidani, M Kudo, R Hiraka, K Takeda, RE Bell, A Maan, DP Boyle, R Majeski, VA Soukhanovskii, M Groth, AG McLean, RS Wilcox, C Lasnier, Kazuo Nakamura, Y Nagashima, R Ikezoe, M Hasegawa, Kengoh Kuroda, A Higashijima, T Nagata, S Shimabukuro, I Niiya, I Sekiya, M Hasuo

    Nuclear Fusion   2023.7

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  • A versatile power supply system for the central solenoid of the QUEST spherical tokamak Reviewed International journal

    Yifan Zhang, Takumi Onchi, Kazuo Nakamura, Yuya Otsuka, Yuji Koide, Qilin Yue, Takahiro Nagata, Shoji Kawasaki, Kengoh Kuroda, Makoto Hasegawa, Ryuya Ikezoe, Takeshi Ido, Kazuaki Hanada, Hiroshi Idei

    Fusion Engineering and Design   191   113648   2023.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  • QUEST Database for Tokamak Big Data Reviewed International journal

    Makoto HASEGAWA, Aki HIGASHIJIMA, Ichiro NIIYA, Kazuaki HANADA, Hiroshi IDEI, Takeshi IDO, Ryuya IKEZOE, Takumi ONCHI, Kengo KURODA, Daisuke SAKURAI

    Plasma and Fusion Research   18   1305048   2023.6

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  • Circuit design for doubling the toroidal magnetic field on the QUEST spherical tokamak Invited Reviewed International journal

    Takumi Onchi, Hiroshi Idei, Nagato Yanagi, Yifan Zhang, Kazuo Nakamura, Kengoh Kuroda, Makoto Hasegawa, Ryuya Ikezoe, Kazuaki Hanada, Takeshi Ido, Masahiro Kobayashi, Yuichi Ogawa, Minoru Yoshitani, Takemi Kawamura

    Circuit design for doubling the toroidal magnetic field on the QUEST spherical tokamak   192   113794   2023.6

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  • Initial testing of ohmic heating through double flux swing during electron cyclotron start-up in the QUEST spherical tokamak Invited Reviewed International journal

    Yifan Zhang, Takumi Onchi, Kazuo Nakamura, Qilin Yue, Takahiro Nagata, Shoji Kawasaki, Kengoh Kuroda, Makoto Hasegawa, Ryuya Ikezoe, Takeshi Ido, Kazuaki Hanada, Hiroshi Idei

    PLASMA SCIENCE & TECHNOLOGY   25 ( 5 )   2023.5

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/2058-6272/acafc2

  • 8.56-GHz quasi-optical launcher system with incident-mode selectivity on the QUEST spherical tokamak Invited Reviewed International journal

    H Idei, M Sakaguchi, K Mishra, T Onchi, R Ikezoe, O Watanabe, Y Tanaka, T Saito, T Ido, K Hanada

    FUSION ENGINEERING AND DESIGN   189   2023.4

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    DOI: 10.1016/j.fusengdes.2023.113479

  • Quaternion Analysis of Transient Phenomena of Motor-Generator Invited Reviewed International journal

    Kazuo Nakamura, Yifan Zhang, Takumi Onchi, Hiroshi Idei, Makoto Hasegawa, Kazutoshi Tokunaga, Kazuaki Hanada, Takeshi Ido, Ryuya Ikezoe, Hirotaka Chikaraishi, Osamu Mitarai, Shoji Kawasaki, Aki Higashijima, Takahiro Nagata, Shun Shimabukuro

    Plasma and Fusion Research   Volume 18(2023)2405035   2023.4

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  • Development of Thomson Scattering Measurement System for Long Duration Discharges on the QUEST Spherical Tokamak Invited Reviewed International journal

    Kaori Kono, Takeshi Ido, Akira Ejiri, Kazuaki Hanada, Qilin Yue, Makoto Hasegawa, Yi Peng, Seiya Sakai, Ryuya Ikezoe, Hiroshi Idei, Syoji Kawasaki, Kengoh Kuroda, Takumi Onchi, Yoshihiko Nagashima, Seowon Jang

    Plasma and Fusion Research   18   1405012-1 - 1405012-4   2023.2

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1585/pfr.18.1405012

  • Improvements to the High-Field-Side Transient CHI System on QUEST Invited Reviewed International journal

    Kengoh Kuroda, R Raman, Makoto Hasegawa, T Onchi, Kazuaki Hanada, M Ono, BA Nelson, J Rogers, R Ikezoe, H Idei, T Ido, O Mitarai, M Nagata, S Kawasaki, T Nagata, A Higashijima, S Shimabukuro, I Niiya, I Sekiya, S Kojima, Kazuo Nakamura, Y Takase, S Murakami

    JOURNAL OF FUSION ENERGY   41 ( 2 )   2022.12

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s10894-022-00338-4

  • Design Considerations for the Implementation of a High-Field-Side Transient CHI System on QUEST Invited Reviewed International journal

    Roger Raman, K Kuroda, K Hanada, Masayuki Ono, Makoto Hasegawa, T Onchi, R Ikezoe, H Idei, T Ido, John A Rogers

    IEEE TRANSACTIONS ON PLASMA SCIENCE   50 ( 11 )   4171 - 4176   2022.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1109/TPS.2022.3193069

  • Conceptual design of a heavy ion beam probe for the QUEST spherical tokamak Invited Reviewed International journal

    T Ido, M Hasegawa, R Ikezoe, T Onchi, K Hanada, H Idei, K Kuroda, Y Nagashima

    REVIEW OF SCIENTIFIC INSTRUMENTS   93 ( 11 )   2022.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1063/5.0101770

  • Adaptive Capon beamforming for lensless electron cyclotron emission imaging with high spatial resolution Invited Reviewed International journal

    H Idei, M Fukuyama, S Sakai, K Mishra, K Nishimura, R Ikezoe, T Onchi, T Ido, K Hanada

    REVIEW OF SCIENTIFIC INSTRUMENTS   93 ( 10 )   2022.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1063/5.0101632

  • Towards automated gas leak detection through cluster analysis of mass spectrometer data Invited Reviewed International journal

    @Makoto Hasegawa, @Daisuke Sakurai, @Aki Higashijima , @Ichiro Niiya, @Keiji Matsushima, @Kazuaki Hanada, @Hiroshi Idei, @Takeshi Ido, @Ryuya Ikezoe, @Takumi Onchi, @Kengo Kuroda

    Fusion Engineering and Design   180   1 - 9   2022.6

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  • Overview of coordinated spherical tokamak research in Japan Invited Reviewed International journal

    Takase, Y.; Ejiri, A.; Fujita, T.; Hanada, K.; Idei, H.; Nagata, M.; Onchi, T.; Ono, Y.; Tanaka, H.; Tsujii, N.; Uchida, M.; Yasuda, K.; Kasahara, H.; Murakami, S.; Takeiri, Y.; Todo, Y.; Tsuji-Iio, S.; Kamada, Y.

    NUCLEAR FUSION   62 ( 4 )   2022.4

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1741-4326/ac29cf

  • Quaternion Analysis of Transient Phenomena in Matrix Converter Based on Space-Vector Modulation Invited Reviewed International journal

    Kazuo NAKAMURA, Yifan ZHANG1), Takumi ONCHI, Hiroshi IDEI, Makoto HASEGAWA, Kazutoshi TOKUNAGA, Kazuaki HANADA, Hirotaka CHIKARAISHI2), Osamu MITARAI3), Shoji KAWASAKI, Aki HIGASHIJIMA, Takahiro NAGATA and Shun SHIMABUKURO

    Plasma and Fusion Research   2022.2

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: DOI: 10.1585/pfr.17.2405025

  • Observation of second harmonic electron cyclotron resonance heating and current-drive transition during non-inductive plasma start-up experiment in QUEST Invited Reviewed International journal

    Kojima, Shinichiro; Hanada, Kazuaki; Idei, Hiroshi; Onchi, Takumi; Ikezoe, Ryuya; Nagashima, Yoshihiko; Hasegawa, Makoto; Kuroda, Kengoh; Nakamura, Kazuo; Higashijima, Aki; Nagata, Takahiro; Kawasaki, Shoji; Shimabukuro, Shun; Elserafy, Hatem; Fukuyama, Masaharu; Ejiri, Akira; Shikama, Taiichi; Yoneda, Nao; Yoneda, Ryota; Kariya, Tsuyoshi; Takase, Yuichi; Murakami, Sadayoshi; Bertelli, Nicola; Ono, Masayuki

    PLASMA PHYSICS AND CONTROLLED FUSION   63 ( 10 )   2021.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1361-6587/ac1838

  • MHD Equilibrium Reconstruction Using the Visible Light Tomographic Method with Laplacian Eigenfunction Reviewed International journal

    Kosuke Suzuki, Sadayoshi Murakami, Satoshi Ohdachi, Hiroshi Idei, Kengoh Kuroda, Ryuya Ikezoe, Takumi Onchi

    Plasma and Fusion Research   2021.7

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  • Designing an upgrade of ohmic heating system for the QUEST spherical tokamak Reviewed International journal

    #Yifan Zhang, @Takumi Onchi, @Kazuo Nakamura, #Akihiro Kidani, #Qilin Yue, @Kengoh Kuroda, @Makoto Hasegawa, @Ryuya Ikezoe, @Hiroshi Idei

    Fusion Engineering and Design   168   112362   2021.7

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  • Overview of recent progress on steady state operation of all-metal plasma facing wall device QUEST Invited Reviewed International journal

    Hanada, K.; Yoshida, N.; Hasegawa, M.; Oya, M.; Oya, Y.; Takagi, I; Hatayama, A.; Shikama, T.; Idei, H.; Nagashima, Y.; Ikezoe, R.; Onchi, T.; Kuroda, K.; Kawasaki, S.; Higashijima, A.; Nagata, T.; Shimabukuro, S.; Nakamura, K.; Murakami, S.; Takase, Y.; Gao, X.; Liu, H.; Qian, J.

    NUCLEAR MATERIALS AND ENERGY   27   2021.6

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.nme.2021.101013

  • Extension of Operation Region for Steady State Operation on QUEST by Integrated Control with Hot Walls Invited Reviewed International journal

    Makoto HASEGAWA, Kazuaki HANADA, Naoaki YOSHIDA, Hiroshi IDEI, Takeshi IDO, Yoshihiko NAGASHIMA, Ryuya IKEZOE, Takumi ONCHI, Kengoh KURODA, Shoji KAWASAKI, Aki HIGASHIJIMA, Takahiro NAGATA, Shun SHIMABUKURO, Kazuo NAKAMURA

    Plasma and Fusion Research   16   2021.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: https://doi.org/10.1585/pfr.16.2402034

  • Quaternion Analysis of a Direct Matrix Converter Based on Space-Vector Modulation Reviewed International journal

    Kazuo Nakamura, Yifan Zhang, Takumi Onchi, Hiroshi Idei, Makoto Hasegawa, Kazutoshi Tokunaga, Kazuaki Hanada, Osamu Mitarai, Shoji Kawasaki, Aki Higashijima, Takahiro Nagata, Shun Shimabukuro

    Plasma and Fusion Research   16   2405037 - 2405037   2021.3

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  • Effects of Toroidally Distributed Divertor Biasing on Scrape-Off-Layer Plasma in the QUEST Spherical Tokamak Reviewed International journal

    Kazuo TOI, Takumi ONCHI, Kengo KURODA, Shinichiro KOJIMA, Hideki ZUSHI, Makoto HASEGAWA, Masaharu FUKUYAMA, Shoji KAWASAKI, Aki HIGASHIJIMA, Ryuya IKEZOE, Hiroshi IDEI, Takeshi IDO, Kazuaki HANADA, QUEST Experiment Group

    Plasma and Fusion Research   16   2021.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: https://doi.org/10.1585/pfr.16.2402024

  • Investigation of radial distribution of atomic hydrogen flux to the plasma facing components in steady state discharges in QUEST tokamak Reviewed International journal

    Kuzmin, A.; Kobayashi, M.; Hanada, K.; Idei, H.; Onchi, T.; Mori, S.; Yoneda, N.; Shikama, T.; Hasuo, M.; Ido, T.; Nagashima, Y.; Ikezoe, R.; Hasegawa, M.; Kuroda, K.; Kono, K.; Matsuo, S.; Nagata, T.; Shimabukuro, S.; Higashijima, A.; Niiya, I; Zushi, H.

    NUCLEAR MATERIALS AND ENERGY   26   100872   2021.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.nme.2020.100872

  • Toroidal flow measurements of impurity ions in QUEST ECH plasmas using multiple viewing chords emission spectroscopy Reviewed International journal

    N Yoneda, T Shikama, K Hanada, S Mori, Takumi Onchi, K Kuroda, M Hasuo, A Ejiri, K Matsuzaki, Y Osawa, Y Peng, Y Kawamata, S Sakamoto, H Idei, T Ido, K Nakamura, Y Nagashima, Ryuya Ikezoe, M Hasegawa, A Higashijima, T Nagata, S Shimabukuro

    Nuclear Materials and Energy   26 ( 3 )   100905-1 - 100905-7   2021.3

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    DOI: https://doi.org/10.1016/j.nme.2021.100905

  • Modeling of solenoid-free start-up using 2nd harmonic electron cyclotron heating and current drive in QUEST Reviewed International journal

    M Ono, N Bertelli, H Idei, K Hanada, Takumi Onchi, S Kojima, H Elserafy

    AIP Conference Proceedings   2254 ( 1 )   090001   2020.9

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  • Spectroscopic Measurement of Hydrogen Atom Density in a Plasma Produced with 28 GHz ECH in QUEST Reviewed International journal

    Satoru Mori, Taiichi Shikama, Kazuaki Hanada, Nao Yoneda, Arseniy Kuzmin, Masahiro Hasuo, Hiroshi Idei, Takumi Onchi, Akira Ejiri, Yuki Osawa, Yi Peng, Kyohei Matsuzaki, Shinichiro Kado, Keiji Sawada, Takeshi Ido, Kazuo Nakamura, Ryuya Ikezoe, Yoshihiko Nagashima, Makoto Hasegawa, Kengo Kuroda, Aki Higashijima, Takahiro Nagata, Shun Shimabukuro

    Atoms   8 ( 3 )   44-1 - 44-8   2020.9

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    DOI: https://doi.org/10.1585/pfr.15.2402063

  • Parametric Decay Wave Observation in HFS X-Mode Injection in QUEST Reviewed International journal

    Shinichiro Kojima, Hatem Elserafy, Kazuaki Hanada, Hiroshi Idei, Ryuya Ikezoe, Yoshihiko Nagashima, Makoto Hasegawa, Takumi Onchi, Kengoh Kuroda, Kazuo Nakamura, Takahiro Murakami, Masaharu Fukuyama, Ryoya Kato, Ryota Yoneda, Masayuki Ono, Akira Ejiri, Yuichi Takase, Sadayoshi Murakami

    Plasma and Fusion Research   15   2402063-1 - 2402063-2   2020.8

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    DOI: https://doi.org/10.1585/pfr.15.2402063

  • Predictive maintenance and safety operation by device integration on the QUEST large experimental device Reviewed International journal

    @Makoto Hasegawa, @Kazuaki Hanada, @Hiroshi Idei, @Shoji Kawasaki, @Takahiro Nagata, @Ryuya Ikezoe, @Takumi Onchi, @Kengoh Kuroda, @Aki Higashijima

    Heliyon   6 ( 6 )   e04214   2020.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.heliyon.2020.e04214

  • Measurement of Dynamic Retention with Fast Ejecting System of Targeted Sample (FESTA) Invited Reviewed International journal

    #Qilin YUE, @Kazuaki HANADA, @Makoto OYA, Shogo MATSUO, #Shinichiro KOJIMA, @Hiroshi IDEI, @Takumi ONCHI, @Kengoh KURODA, @Naoaki YOSHIDA, @Ryuya IKEZOE, Yukai LIU, @Makoto HASEGAWA, @Shun SHIMABUKURO, @Aki HIGASHIJIMA, @Takahiro NAGATA and @Shoji KAWASAKI

    Plasma and Fusion Research   15 ( 2402013 )   2402013-1 - 2402013-5   2020.4

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1585/pfr.15.2402013

  • Electron Bernstein wave conversion of high-field side injected X-modes in QUEST Reviewed

    Hatem Elserafy, Kazuaki Hanada, Shinichiro Kojima, Takumi Onchi, Ryuya Ikezoe, Kengoh Kuroda, Hiroshi Idei, Makoto Hasegawa, Ryota Yoneda, Masaharu Fukuyama, Arseniy Kuzmin, Aki Higashijima, Takahiro Nagata, Shoji Kawasaki, Shun Shimabukuro, Nicola Bertelli, Masayuki Ono

    Plasma Physics and Controlled Fusion   62 ( 3 )   2020.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1361-6587/ab6903

  • Electron heating of over-dense plasma with dual-frequency electron cyclotron waves in fully non-inductive plasma ramp-up on the QUEST spherical tokamak Reviewed

    H. Idei, T. Onchi, K. Mishra, H. Zushi, T. Kariya, T. Imai, O. Watanabe, R. Ikezoe, K. Hanada, M. Ono, A. Ejiri, J. Qian, K. Nakamura, A. Fujisawa, Y. Nagashima, M. Hasegawa, K. Matsuoka, A. Fukuyama, S. Kubo, M. Yoshikawa, M. Sakamoto, S. Kawasaki, A. Higashijima, S. Ide, Y. Takase, S. Murakami

    Nuclear Fusion   60 ( 1 )   2020.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1741-4326/ab4c12

  • High voltage electrical system of 8.56 GHz CW klystron for electron cyclotron heating on QUEST spherical tokamak Reviewed

    Takumi Onchi, Hiroshi Idei, K. Nakamura, T. Nagata, S. Kawasaki, R. Ashida, M. Fukuyama, Makoto Hasegawa, Ryuya Ikezoe, A. Higashijima, K. Kuroda, Yoshihiko Nagashima, Kazuaki Hanada

    Fusion Engineering and Design   146   2567 - 2570   2019.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.fusengdes.2019.04.043

  • Quasi-optical polarizer system for ECHCD experiments in the QUEST Reviewed

    M. Fukuyama, Hiroshi Idei, T. I. Tsujimura, S. Kubo, S. Kobayashi, M. Yunoki, Takumi Onchi, Ryuya Ikezoe

    Fusion Engineering and Design   146   1437 - 1440   2019.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.fusengdes.2019.02.099

  • Plasma equilibrium based on EC-driven current profile with toroidal rotation on QUEST Reviewed

    K. Nakamura, M. M. Alam, Y. Z. Jiang, O. Mitarai, M. Takechi, M. Hasegawa, K. Tokunaga, K. Hanada, H. Idei, Y. Nagashima, T. Onchi, K. Kuroda, O. Watanabe, A. Higashijima, T. Nagata, S. Shimabukuro, S. Kawasaki, A. Fukuyama

    Fusion Engineering and Design   146   2628 - 2631   2019.9

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    DOI: 10.1016/j.fusengdes.2019.04.059

  • Estimation of fuel particle balance in steady state operation with hydrogen barrier model Reviewed

    Kazuaki Hanada, N. Yoshida, I. Takagi, T. Hirata, A. Hatayama, K. Okamoto, Y. Oya, T. Shikama, Z. Wang, H. Long, C. Huang, M. Oya, Hiroshi Idei, Yoshihiko Nagashima, Takumi Onchi, Makoto Hasegawa, K. Nakamura, H. Zushi, K. Kuroda, S. Kawasaki, A. Higashijima, T. Nagata, S. Shimabukuro, Y. Takase, S. Murakami, X. Gao, H. Liu, J. Qian, R. Raman, M. Ono

    Nuclear Materials and Energy   19   544 - 549   2019.5

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    DOI: 10.1016/j.nme.2019.03.015

  • Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST Reviewed

    K. Hanada, N. Yoshida, M. Hasegawa, A. Hatayama, K. Okamoto, I. Takagi, T. Hirata, Y. Oya, M. Miyamoto, M. Oya, T. Shikama, A. Kuzmin, Z. X. Wang, H. Long, H. Idei, Y. Nagashima, K. Nakamura, O. Watanabe, T. Onchi, H. Watanabe, K. Tokunaga, A. Higashijima, S. Kawasaki, T. Nagata, S. Shimabukuro, Y. Takase, S. Murakami, X. Gao, H. Liu, J. Qian, R. Raman, M. Ono

    Nuclear Fusion   59 ( 7 )   2019.5

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    DOI: 10.1088/1741-4326/ab1858

  • Development of high power gyrotrons for advanced fusion devices Reviewed

    T. Kariya, R. Minami, T. Imai, M. Okada, F. Motoyoshi, T. Numakura, Y. Nakashima, Hiroshi Idei, Takumi Onchi, Kazuaki Hanada, T. Shimozuma, Y. Yoshimura, H. Takahashi, S. Kubo, Y. Oda, R. Ikeda, K. Sakamoto, M. Ono, K. Nagasaki, T. Eguchi, Y. Mitsunaka

    Nuclear Fusion   59 ( 6 )   2019.4

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    DOI: 10.1088/1741-4326/ab0e2c

  • 28-GHz ECHCD system with beam focusing launcher on the QUEST spherical tokamak Reviewed

    Hiroshi Idei, Takumi Onchi, T. Kariya, T. I. Tsujimura, S. Kubo, S. Kobayashi, M. Sakaguchi, T. Imai, Makoto Hasegawa, K. Nakamura, K. Mishra, M. Fukuyama, M. Yunoki, S. Kojima, O. Watanabe, K. Kuroda, Kazuaki Hanada, Yoshihiko Nagashima, A. Ejiri, N. Matsumoto, M. Ono, A. Higashijima, T. Nagata, S. Shimabukoro, Y. Takase, A. Fukuyama, S. Murakami

    Fusion Engineering and Design   2019.1

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    DOI: 10.1016/j.fusengdes.2019.02.027

  • Prototype phased-array patch loop antennae for electron cyclotron emission diagnostics Reviewed

    Masaharu Fukuyama, Hiroshi Idei, Miu Yunoki, Ryuichi Ashida, Daichi Ogata, Ryuya Ikezoe, Takumi Onchi

    Plasma and Fusion Research   14   2019.1

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    DOI: 10.1585/PFR.14.3402111

  • Improvement of aperture configuration to reduce the stray light for Thomson scattering measurement using a peripheral beam profile monitor Reviewed

    Yuya Kawamata, Akira Ejiri, Kyohei Matsuzaki, Yuichi Takase, Naoto Tsujii, Takumi Onchi, Yoshihiko Nagashima

    Plasma and Fusion Research   14   2019.1

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    DOI: 10.1585/PFR.14.1402072

  • HFS injection of X-mode for EBW conversion in QUEST Reviewed

    Hatem Elserafy, Kazuaki Hanada, Kengoh Kuroda, Hiroshi Idei, Ryota Yoneda, Canbin Huang, Shinichiro Kojima, Makoto Hasegawa, Yoshihiko Nagashima, Takumi Onchi, Ryuya Ikezoe, Aki Higashijima, Takahiro Nagata, Shoji Kawasaki, Shun Shimabukuro, Nicola Bertelli, Masayuki Ono

    Plasma and Fusion Research   14 ( 1 )   2019.1

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    DOI: 10.1585/pfr.14.1205038

  • Initial results from solenoid-free plasma start-up using Transient CHI on QUEST Reviewed

    K. Kuroda, R. Raman, Kazuaki Hanada, Makoto Hasegawa, Takumi Onchi, M. Ono, B. A. Nelson, T. R. Jarboe, M. Nagata, O. Mitarai, K. Nakamura, Hiroshi Idei, J. Rogers, S. Kawasaki, T. Nagata, A. Kuzmin, S. Kojima, C. Huang, O. Watanabe, A. Higashijima, Y. Takase, A. Fukuyama, S. Murakami

    Plasma Physics and Controlled Fusion   60 ( 11 )   2018.9

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    DOI: 10.1088/1361-6587/aadcb7

  • Effect of magnetic shear on edge turbulence in SOL-like open field line configuration in QUEST Reviewed

    Santanu Banerjee, H. Zushi, N. Nishino, Kazuaki Hanada, Hiroshi Idei, K. Nakamura, Makoto Hasegawa, akihide fujisawa, Yoshihiko Nagashima, K. Mishra, S. Tashima, Takumi Onchi, A. Kuzmin, K. Matsuoka

    Plasma Physics and Controlled Fusion   60 ( 8 )   2018.6

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    DOI: 10.1088/1361-6587/aacb69

  • Modification of plasma control system and hot-wall temperature control system for long-duration plasma sustainment in QUEST Reviewed

    Makoto Hasegawa, Kazuo Nakamura, Kazuaki Hanada, Shoji Kawasaki, Arseniy Kuzmin, Hiroshi Idei, Kazutoshi Tokunaga, Yoshihiko Nagashima, Takumi Onchi, Kengoh Kuroda, Osamu Watanabe, Aki Higashijima, Takahiro Nagata

    Fusion Engineering and Design   129   202 - 206   2018.4

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    DOI: 10.1016/j.fusengdes.2018.02.069

  • Spectroscopic measurements of impurity ion toroidal and poloidal flow velocities and their dependence on vertical magnetic field in QUEST toroidal ECR plasmas Reviewed

    Nao Yoneda, Taiichi Shikama, Hideki Zushi, Kazuaki Hanada, Akinobu Fujikawa, Takumi Onchi, Kengoh Kuroda, Kuniaki Nii, Masahiro Hasuo, Makoto Hasegawa, Hiroshi Idei, Kazuo Nakamura, Yoshihiko Nagashima, Aki Higashijima, Takahiro Nagata

    Plasma and Fusion Research   13   2018.1

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    DOI: 10.1585/PFR.13.3402087

  • Fully non-inductive second harmonic electron cyclotron plasma ramp-up in the QUEST spherical tokamak Reviewed

    Hiroshi Idei, T. Kariya, T. Imai, K. Mishra, Takumi Onchi, O. Watanabe, H. Zushi, Kazuaki Hanada, J. Qian, A. Ejiri, M. M. Alam, K. Nakamura, akihide fujisawa, Yoshihiko Nagashima, Makoto Hasegawa, K. Matsuoka, A. Fukuyama, S. Kubo, T. Shimozuma, M. Yoshikawa, M. Sakamoto, S. Kawasaki, H. Nakashima, A. Higashijima, S. Ide, T. Maekawa, Y. Takase, K. Toi

    Nuclear Fusion   57 ( 12 )   2017.10

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    DOI: 10.1088/1741-4326/aa7c20

  • Momentum injection and repetitive CT operation experiments Reviewed

    C. Xiao, A. Rohollahi, Takumi Onchi, M. Dreval, S. Elgriw, A. Hirose

    Radiation Effects and Defects in Solids   172 ( 9-10 )   713 - 717   2017.10

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    DOI: 10.1080/10420150.2017.1398244

  • Investigation of hydrogen recycling in long-duration discharges and its modification with a hot wall in the spherical tokamak QUEST Reviewed

    Kazuaki Hanada, N. Yoshida, T. Honda, Z. Wang, A. Kuzmin, I. Takagi, T. Hirata, Y. Oya, M. Miyamoto, H. Zushi, Makoto Hasegawa, K. Nakamura, akihide fujisawa, Hiroshi Idei, Yoshihiko Nagashima, O. Watanabe, Takumi Onchi, K. Kuroda, H. Long, Hideo Watanabe, Kazutoshi Tokunaga, A. Higashijima, S. Kawasaki, T. Nagata, Y. Takase, A. Fukuyama, O. Mitarai

    Nuclear Fusion   57 ( 12 )   2017.10

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    DOI: 10.1088/1741-4326/aa8121

  • Spatial distribution of atomic and ion hydrogen flux and its effect on hydrogen recycling in long duration confined and non-confined plasmas Reviewed

    A. Kuzmin, H. Zushi, I. Takagi, S. K. Sharma, M. Kobayashi, Y. Hirooka, Takumi Onchi, Kazuaki Hanada, N. Yoshida, K. Nakamura, akihide fujisawa, Hiroshi Idei, Yoshihiko Nagashima, Makoto Hasegawa, T. Mutoh, K. Mishra, H. Ohwada

    Nuclear Materials and Energy   12   627 - 632   2017.8

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    DOI: 10.1016/j.nme.2017.03.027

  • Comparative studies of inner and outer divertor discharges and a fueling study in QUEST Invited Reviewed International journal

    O. Mitarai, K. Nakamura, M. Hasegawa, T. Onchi, H. Idei, A. Fujisawa, K. Hanada, H. Zushi, A. Higashijima, H. Nakashima, S. Kawasaki, K. Matsuoka, S. Koike, T. Takahashi, H. Tsutsui

    FUSION ENGINEERING AND DESIGN   109   1365 - 1370   2016.11

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    DOI: 10.1016/j.fusengdes.2015.12.022

  • Response of the far scrape-off layer plasma to strong gas puffing in the high poloidal beta configuration of the QUEST spherical tokamak Invited Reviewed International journal

    T. Onchi, H. Zushi, K. Mishra, Y. Oyama, Y. Nagashima, K. Hanada, H. Idei, M. Hasegawa, A. Kuzmin, H. Miura, K. Nakamura, A. Fujisawa, K. Nagaoka

    PLASMA PHYSICS AND CONTROLLED FUSION   58 ( 11 )   2016.11

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    DOI: 10.1088/0741-3335/58/11/115004

  • Observation of an edge coherent mode and poloidal flow in the electron cyclotron wave induced high beta(p) plasma in QUEST Invited Reviewed International journal

    S. Banerjee, H. Zushi, N. Nishino, K. Mishra, K. Mahira, S. Tashima, A. Ejiri, T. Yamaguchi, T. Onchi, Y. Nagashima, K. Hanada, K. Nakamura, H. Idei, M. Hasegawa, A. Fujisawa, A. Kuzmin, K. Matsuoka

    PHYSICS OF PLASMAS   23 ( 8 )   2016.8

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    DOI: 10.1063/1.4960117

  • Hydrogen flux measurements with permeation probes in spherical tokamak QUEST Reviewed International journal

    A Kuzmin, H Zushi, I Takagi, SK Sharma, Y Hirooka, M Kobayashi, M Sakamoto, K Hanada, T Onchi, Y Oyama, N Youshida, K Nakamura, A Fujisawa, H Idei, Y Nagashima, M Hasegawa, K Mishra

    Vacuum   129   2016.4

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  • Adaptive-array Electron Cyclotron Emission diagnostics using data streaming in a Software Defined Radio system Reviewed International journal

    H Idei, K Mishra, MK Yamamoto, M Hamasaki, A Fujisawa, Y Nagashima, Y Hayashi, T Onchi, K Hanada, H Zushi

    Journal of Instrumentation   11 ( 4 )   2016.4

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  • Tomography as a promising diagnostic tool for plasma turbulence Reviewed International journal

    A Fujisawa, Y Nagashima, S Inagaki, T Onchi, S Ohshima, A Shimizu

    Plasma Physics and Controlled Fusion   58 ( 2 )   2016.2

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  • Multiple wall-reflection effect in adaptive-array differential-phase reflectometry on QUEST Reviewed International journal

    H Idei, K Mishra, MK Yamamoto, A Fujisawa, Y Nagashima, M Hamasaki, Y Hayashi, T Onchi, K Hanada, H Zushi

    Journal of Instrumentation   11 ( 1 )   2016.1

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  • Comparative studies of inner and outer divertor discharges and a fueling study in QUEST Reviewed International journal

    O Mitarai, K Nakamura, M Hasegawa, T Onchi, H Idei, A Fujisawa, K Hanada, H Zushi, A Higashijima, H Nakashima, S Kawasaki, K Matsuoka, S Koike, T Takahashi, H Tsutsui

    Fusion Engineering and Design   2015.12

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  • Global gas balance and influence of atomic hydrogen irradiation on the wall inventory in steady-state operation of QUEST tokamak Reviewed International journal

    A. Kuzmin, H. Zushi, I. Takagi, S.K. Sharma, A. Rusinov, Y. Inoue, Y. Hirooka, H. Zhou, M. Kobayashi, M. Sakamoto, K. Hanada, N. Yoshida, K. Nakamura, A. Fujisawa, K. Matsuoka, H. Idei, Y. Nagashima, M. Hasegawa, T. Onchi, S. Banerjee, K. Mishra

    Journal of Nuclear Materials   463   2015.8

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  • Heat flux and plasma flow in the far scrape-off layer of the inboard poloidal field null configuration in QUEST Reviewed International journal

    T. Onchi, H. Zushi, K. Mishra, Y. Mahira, K. Nagaoka, K. Hanada, H. Idei, M. Hasegawa, K. Nakamura, A. Fujisawa, Y. Nagashima, K. Matsuoka, S. Tashima, S. Banerjee, A. Kuzmin, S. Kawasaki, H. Nakashima, A. Higashijima, O. Watanabe

    Physics of Plasmas   22 ( 8 )   2015.8

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  • Self organization of high βp plasma equilibrium with an inboard poloidal magnetic field null in QUEST Reviewed International journal

    55 ( 8 )   2015.8

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  • Observation of heat flux and plasma flow in scrape off layer in QUEST Reviewed International journal

    T. Onchi, Y. Mahira, K. Nagaoka, S. Tashima, S. Banerjee, K. Mishra, H. Idei, K. Hanada, K. Nakamura, A. Fujisawa, Y. Nagashima, M. Hasegawa, K. Matsuoka, A. Kuzmin, O. Watanabe, S. Kawasaki, H. Nakashima, A. Higashijima

    Journal of Nuclear Materials   463   2015.8

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  • Particle balance in long duration RF driven plasmas on QUEST Reviewed

    K. Hanada, H. Zushi, N. Yoshida, N. Yugami, T. Honda, M. Hasegawa, K. Mishra, A. Kuzmin, K. Nakamura, A. Fujisawa, H. Idei, Y. Nagashima, O. Watanabe, T. Onchi, H. Watanabe, K. Tokunaga, A. Higashijima, S. Kawasaki, H. Nakashima, Y. Takase, A. Fukuyama, O. Mitarai, Y.K.M. Peng

    Journal of Nuclear Materials   463   2015.8

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  • Dynamical programming based turbulence velocimetry for fast visible imaging of tokamak plasma Reviewed International journal

    S. Banerjee, H. Zushi, N. Nishino, K. Mishra, T. Onchi, A. Kuzmin, Y. Nagashima, K. Hanada, K. Nakamura, H. Idei, M. Hasegawa, A. Fujisawa

    Review of Scientific Instruments   86 ( 3 )   2015.3

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  • Thermal imaging of plasma with a phased array antenna in QUEST Reviewed International journal

    K. Mishra, H. Idei, H. Zushi, K. Nagata, R. Akimoto, M. K. Yamamoto, K. Hanada, M. Hasegawa, K. Nakamura, A. Fujisawa, Y. Nagashima, S. Banerjee, T. Onchi, A. Kuzmin

    Review of Scientific Instruments   85 ( 11 )   2014.11

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  • Design and implementation of fast charging circuit for repetitive compact torus injector Reviewed International journal

    T. Onchi, D. McColl, M. Dreval, S. Wolfe, C. Xiao, A. Hirose

    Fusion Engineering and Design   89 ( 11 )   2014.11

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  • A prototype diagnostics system to detect ultraviolet emission for plasma turbulence Reviewed International journal

    T. Onchi, A. Fujisawa, A. Sanpei

    Review of Scientific Instruments   85 ( 11 )   2014.11

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  • Plasma current sustainment after iron core saturation in the STOR-M tokamak Reviewed International journal

    O. Mitarai, Y. Ding, M. Hubeny, Y. Lu, T. Onchi, D. McColl, C. Xiao, A. Hirose

    Fusion Engineering and Design   89 ( 9-10 )   2014.10

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  • Plasma confinement modification and convective transport suppression in the scrape-off layer using additional gas puffing in the STOR-M tokamak Reviewed International journal

    M. Dreval, M. Hubeny, Y. Ding, T. Onchi, Y. Liu, K. Hthu, S. Elgriw, C. Xiao, A. Hirose

    Plasma Physics and Controlled Fusion   55 ( 3 )   2013.3

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  • Asymmetric toroidal flux generation due to phase locking of internally resonant tearing modes in the RELAX reversed-field pinch Reviewed International journal

    R. Ikezoe, S. Masamune, K. Oki, A. Sanpei, H. Himura, T. Onchi, A. Hirose

    Plasma Physics and Controlled Fusion   55 ( 1 )   2013.1

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  • Phase Locking and Unlocking Associated with Transition to Quasi-Single Helicity State in the RELAX Reversed-Field Pinch Reviewed International journal

    R. Ikezoe, S. Masamune, K. Oki, A. Sanpei, H. Himura, T. Onchi, A. Hirose

    Journal of the Physical Society of Japan   81 ( 11 )   2012.10

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  • Modification of toroidal flow in the STOR-M tokamak International journal

    C. Xiao, S. Elgriw, Y. Liu, T. Onchi, M. Dreval, M. Hubeny, Y. Ding, T. Asai, A. Hirose

    Proc. 24th Int. Conf. on Fusion Energy (San Diego, CA, 2012)   2012.10

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  • Design and Initial Result of Time-Resolved Vertical Soft X-Ray Imaging System in Low-A RFP Reviewed International journal

    A. Sanpei, K. Oki, D. Fukahori, K. Deguchi, S. Nakaki, K. Nishimura, H. Himura, S. Masamune, S. Ohdachi, N. Nishino, T. Onchi

    Plasma and Fusion Research   7   2012.6

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  • Fuelling Effect of Tangential Compact toroid injection in STOR-M Tokamak Reviewed International journal

    T. Onchi, Y. Liu, M. Dreval, D. McColl, T. Asai, S. Wolfe, C. Xiao and A. Hirose

    CNS(Canadian Nuclear Society)2012 conference paper   2012.6

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  • Recent Experiments on the STOR-M Tokamak Reviewed International journal

    C. Xiao, T.Onchi, Y. Liu, S. Elgriw, M.Dreval, D. McColl, T. Asai, and A. Hirose

    CNS(Canadian Nuclear Society)2012 conference paper   2012.6

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  • Tangential Image of Helical SXR Emissivity Structure in Low-Aspect-Ratio RFP Reviewed International journal

    A. Sanpei, K. Oki, M. Nakamura, A. Higashi, H. Motoi, D. Fukahori, H. Himura, S. Masamune, S. Ohdachi, N. Nishino, T. Onchi, R. Ikezoe

    Plasma Science, IEEE Transactions on   39 ( 11 )   2011.11

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  • Observation of Helical Structure by Imaging Diagnostics in a Low-Aspect-Ratio Reversed Field Pinch Reviewed International journal

    T. Onchi, R. Ikezoe, K. Oki, A. Sanpei, H. Himura, S. Masamune, N. Nishino, H. Koguchi

    Journal of the Physical Society of Japan   80 ( 11 )   2011.10

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  • Initial Result of Successive SXR Imaging Measurement in Low-A RFP Reviewed International journal

    A. SANPEI, K. OKI, M. NAKAMURA, A. HIGASHI, H. MOTOI, D. FUKAHORI, H. HIMURA, S. MASAMUNE, S. OHDACHI, N. NISHINO, T. ONCHI, R. IKEZOE

    Plasma and Fusion Research   6   2011.7

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  • Extended operational regimes and MHD behavior in a low-aspect-ratio reversed field pinch in RELAX Reviewed International journal

    R. Ikezoe, K. Oki, T. Onchi, Y. Konishi, M. Sugihara, S. Fujita, A. Sanpei, H. Himura, S. Masamune

    Plasma Physics and Controlled Fusion   53 ( 2 )   2011.2

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  • Density Regimes of Low-Aspect-Ratio RFP Plasmas in RELAX Reviewed International journal

    M. Sugihara, K. Oki, R. Ikezoe, T. Onchi, A. Sanpei, H. Himura, S. Masamune, T. Akiyama, A. Ejiri, K. Sakamoto, K. Nagasaki, V. Zhuravlev

    Plasma and Fusion Research   5   2010.12

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  • Recent Progress in Low-A RFP Plasma Research in RELAX Reviewed International journal

    A. Sanpei, R. Ikezoe, T. Onchi, K. Oki, M. Sugihara, Y. Konishi, S. Fujita, M. Nakamura, A. Higashi, H. Motoi, H. Himura, S. Masamune

    Plasma and Fusion Research   5   2010.12

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  • MHD Properties of Low-aspect Ratio RFP in RELAX Reviewed International journal

    S Masamune, A Sanpei, R Ikezoe, T Onchi, K Oki, T Yamashita, H Shimazu, H Himura, R Paccagnella

    Journal of fusion energy   28 ( 2 )   2009.2

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  • Equilibrium Reconstruction and Estimation of Neoclassical Effect in Low-Aspect-Ratio Reversed Field Pinch Experiments on RELAX Reviewed International journal

    Akio Sanpei, Kensuke Oki, Ryuya Ikezoe, Takumi Onchi, Ken-Ichi Murata, Hiroyuki Shimazu, Tetsuo Yamashita, Shinichi Fujita, Haruhiko Himura, Sadao Masamune, Jay K Anderson

    Journal of the Physical Society of Japan   78 ( 1 )   2009.1

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  • Effects of Loowering the Aspect Ratio on MHD Behaviour in a Reversed Field Pinch International journal

    S. Masamune, A. Sanpei, R. Ikezoe, T. Onchi, K. Oki, T. Yamashita, H. Shimazu, K. Murata, H. Himura, N. Nishino, R. Paccagnella

    Proc. 22th Int. Conf. on Fusion Energy (Geneva, 2008)   2008.10

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  • Observation of large-scale profile change of magnetic field in a low-aspect ratio reversed field pinch Reviewed International journal

    Kensuke Oki, Ryuya Ikezoe, Takumi Onchi, Akio Sanpei, Haruhiko Himura, Sadao Masamune, Roberto Paccagnella

    Journal of the Physical Society of Japan   77 ( 7 )   2008.7

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  • Quasi-periodic growth of a single helical instability in a low-aspect ratio RFP Reviewed International journal

    Ryuya Ikezoe, Takumi Onchi, Kensuke Oki, Akio Sanpei, Haruhiko Himura, Sadao Masamune

    Plasma and Fusion Research   3   2008.5

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  • Observation of Simple Helical Structure in Low Aspect Ratio RFP Using Fast Camera Reviewed International journal

    Takumi Onchi, Nobuhiro Nishino, Ryuya Ikezoe, Akio Sanpei, Haruhiko Himura, Sadao Masamune

    Plasma and Fusion Research   3   2008.1

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  • Application of Soft X-Ray Imaging System to the STE-2 RFP Reviewed International journal

    Takumi Onchi, Akio Sanpei, Ryuya Ikezoe, Haruhiko Himura, Sadao Masamune

    Plasma and Fusion Research   2   2007.11

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  • Characterization of Initial Low-Aspect Ratio RFP Plasmas in “RELAX” Reviewed International journal

    76 ( 12 )   2007.11

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  • Design of Soft-X Ray Imaging System for Magnetic Islands of RFP Plasmas Reviewed International journal

    Akio Sanpei, Takumi Onchi, Ryuya Ikezoe, Haruhiko Himura, Sadao Masamune

    Plasma and Fusion Research   2   2007.11

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  • Research plans for low-aspect ratio reversed field pinch Reviewed International journal

    S Masamune, A Sanpei, H Himura, R Ikezoe, T Onchi, M Nagata, H Hiramatsu, D Ishijima

    Fusion science and technology   51 ( 2 )   1900

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    Language:English   Publishing type:Research paper (scientific journal)  

  • Characterization of equilibria in a low-aspect-ratio RFP Reviewed International journal

    Akio Sanpei, Kensuke Oki, Ryuya Ikezoe, Takumi Onchi, Hiroyuki Shimazu, Tetsuo Yamashita, Haruhiko Himura, Sadao Masamune

    Journal of Plasma Fusion Research SERIES   8   1900

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    Language:English   Publishing type:Research paper (scientific journal)  

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Presentations

  • TASK/WRを用いたQUEST電流立ち上げ実験の28GHz-電子サイクロトロン波解析

    恩地拓己,出射浩,池添竜也,福山雅治,長谷川真,花田和明,江尻晶,小野雅之,福山淳

    第34回プラズマ・核融合学会 年会  2019.12 

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    Event date: 2019.12

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:大阪大学吹田キャンパス内コンベンションセンター   Country:Japan  

  • Second harmonic EC plasma ramp-up through production of energetic electrons on the QUEST spherical tokamak International conference

    Takumi Onchi, H. Idei, M. Hasegawa, K. Kuroda, R. Ikezoe, K. Hanada, A. Ejiri, T. Kariya, S. Kubo, T.I. Tsujimura, A. Fukuyama

    60th Annual Meeting of the APS Division of Plasma Physics  2019.11 

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    Event date: 2019.11

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  • High voltage electrical system of 8.56 GHz CW klystron for electron cyclotron heating on QUEST spherical tokamak International conference

    T. Onchi, H. Idei, K. Nakamura, T. Nagata, S. Kawasaki, R. Ashida, M. Fukuyama, M. Hasegawa, R. Ikezoe, A. Higashijima, K. Kuroda, Y. Nagashima, and K. Hanada

    30th Symposium on Fusion Technology (SOFT2018)  2018.9 

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    Event date: 2018.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Italy  

  • 順列エントロピーと統計的複雑性を用いたプラズマ実験データの評価 Invited

    恩地拓己

    プラズマ科学のフロンティア 2017 研究会  2017.8 

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    Event date: 2018.5

    Language:Japanese   Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Venue:核融合科学研究所   Country:Japan  

  • Electron cyclotron heating/current-drive system using high power tubes for QUEST spherical tokamak International conference

    TAKUMI ONCHI, H. IDEI, M.HASEGAWA, T. NAGATA, K. KURODA, K. HANADA, T. KARIYA, S. KUBO, T.I. TSUJIMURA, S. KOBAYASHI, NIFS, QUEST TEAM

    59th Annual Meeting of the APS Division of Plasma Physics  2017.10 

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    Event date: 2018.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  • Non-inductive current built-up by local electron cyclotron heating and current drive with a 28 GHz focused beam on QUEST International conference

    Takumi Onchi, Hiroshi Idei, Makoto Hasegawa, Hiroaki Ohwada, Hideki Zushi, Kazuaki Hanada, Tsuyoshi Kariya, Kishore Mishra, Taichi Shikama, Quest Team

    58th Annual Meeting of the APS Division of Plasma Physics  2016.11 

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    Event date: 2018.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:United States  

  • Present status of current-drive system in QUEST spherical tokamak Invited International conference

    T. Onchi, H. Idei, K. Nakamura, M. Hasegawa, K. Yamasaki, O. Watanabe, K. Mishra, K. Kuroda, A. Kuzmin, H. Ohwada, A. Ejiri, H. Togashi, N. Matsumoto and K. Hanada

    AAPPS-DPP 2017  2017.9 

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    Event date: 2018.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:China  

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MISC

  • 実験データの新しい解析方法 -順列エントロピーと統計的複雑性を用いた時系列データ評価-

    恩地 拓己

    プラズマ核融合学会学会誌   2017.4

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    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

    ノイズを含んだ時系列データを解析する際,順列エントロピーと統計的複雑性を求めることで従来よりも再現よくカオス性,ランダム性,周期性などの特性を区別して理解することが可能になった.近年では基礎プラズマ実験やトカマク・逆磁場ピンチなどの高温プラズマ実験で得られる時系列データへ適用した研究結果が発表され始めている.本稿では順列エントロピーと統計的複雑性を求める計算手法を示し,視覚的な理解に役立つC-H面を利用した特性評価方法について解説する.

Professional Memberships

  • The Japan Society of Plasma Science and Nuclear Fusion Research

  • The Physical Society of Japan

  • American Physical Society

Academic Activities

  • Screening of academic papers

    Role(s): Peer review

    2024

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

  • Screening of academic papers

    Role(s): Peer review

    2023

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:3

  • Screening of academic papers

    Role(s): Peer review

    2022

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:5

  • Screening of academic papers

    Role(s): Peer review

    2021

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

  • Screening of academic papers

    Role(s): Peer review

    2020

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

  • Screening of academic papers

    Role(s): Peer review

    2019

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    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

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Research Projects

  • QUESTにおける新規ダイバータバイアスによって生成されるスクレイプオフ層(SOL)電流フィラメントと共鳴磁場摂動の最適化

    2023.4 - 2024.3

    共同研究

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    Authorship:Principal investigator  Grant type:Other funds from industry-academia collaboration

  • 先進炉での非誘導・炉心プラズマ立ち上げに向けた共鳴速度空間制御加熱とその機構解明

    Grant number:21H01067  2023 - 2025

    日本学術振興会  科学研究費助成事業  基盤研究(B)

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    Authorship:Coinvestigator(s)  Grant type:Scientific research funding

  • QUESTの高磁場化に向けたコイル電流モニター開発及びトロイダル磁場測定

    2022.4 - 2023.3

    共同研究

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    Authorship:Principal investigator  Grant type:Other funds from industry-academia collaboration

  • 複数EC高調波による加熱電流駆動で生成される高エネルギー電子の制動放射計測

    Grant number:21K03510  2021 - 2023

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • QUESTの高トロイダル磁場化検討

    2019.4 - 2022.3

    共同研究

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    Authorship:Principal investigator  Grant type:Other funds from industry-academia collaboration

  • GAMMA10/PDXダイバータ上流領域におけるドップラー分光を用いた磁力線方向フロー計測

    2016.4 - 2018.3

    共同研究

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    Authorship:Principal investigator  Grant type:Other funds from industry-academia collaboration

  • 定常化球状トカマク開磁気面領域における能動的放射損失が誘起する熱流変動

    Grant number:15K17800  2015 - 2016

    科学研究費助成事業  若手研究(B)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 軟X線計測による低アスペクト比RFPプラズマの内部磁場構造測定

    Grant number:08J10258  2008 - 2009

    日本学術振興会  科学研究費助成事業  特別研究員奨励費

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    Authorship:Principal investigator  Grant type:Scientific research funding

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Class subject

  • プラズマ理工学演習

    2023.10 - 2024.3   Second semester

  • プラズマ理工学演習

    2022.10 - 2023.3   Second semester

  • プラズマ理工学演習

    2021.10 - 2022.3   Second semester