Updated on 2024/09/30

Information

 

写真a

 
KINOSHITA TOSHIKI
 
Organization
Research Institute for Applied Mechanics Advanced Fusion Research Center Assistant Professor
Interdisciplinary Graduate School of Engineering Sciences Department of Interdisciplinary Engineering Sciences(Concurrent)
Title
Assistant Professor
Contact information
メールアドレス
Tel
0925837483
Profile
核融合発電の実現にはプラズマを高温高密度で保持する必要があります.しかし,プラズマに存在する微小かつ不規則な乱れ(乱流)によってエネルギーや粒子の輸送が生じ,プラズマの性能が劣化してしまいます.私はプラズマ計測器の開発を通じて乱流が生じるメカニズムを理解し,それを抑制するためのプラズマの制御方法や将来の炉設計への応用を目指しています.

Degree

  • Doctor of Philosophy in Engineering

Research Interests・Research Keywords

  • Research theme:Real-time plasma control under low-turbulence conditions focusing on turbulence transition

    Keyword:LHD,plasma control,turbulence transport, high-temperature plasma, confinement

    Research period: 2023.4 - 2024.12

  • Research theme:Development of FM-Reflectometry in QUEST

    Keyword:high-temperature plasma, microwave measurement

    Research period: 2023.4 - 2024.12

  • Research theme:Turbulence transition in LHD and their role in hydrogen isotope plasmas

    Keyword:LHD, turbulence transport, high-temperature plasma, confinement

    Research period: 2022.4 - 2024.12

Awards

  • Early Career Poster Award

    2023.10   29th IAEA Fusion Energy Conference  

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    In this study, we discover a turbulence transition and its role in the isotope effects in the Large Helical Device (LHD). Two types of experiments and simulations suggest that the dominant turbulence is the ion-temperature gradient (ITG) turbulence in the low-density regime and resistive-interchange (RI) turbulence in the high-density regime. Negligible isotope effects in the turbulences and transports of hydrogen (H) and deuterium (D) plasma were found in the ITG regime. However, clear isotope effects were observed in the RI regime. In the RI regime, the turbulences and transports were clearly suppressed, and the confinements were improved in D plasma. The reduction of the turbulence level in the RI regime of the D plasma is likely due to the heavier ion mass and lower resistivity in D plasma, which suppress the linear growth rate of RI turbulence.

  • Early Career Poster Award

    2023.10   29th IAEA Fusion Energy Conference   Turbulence transition and its role in isotope effects in LHD

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Papers

  • Turbulence Transition in Magnetically Confined Hydrogen and Deuterium Plasmas

    T. Kinoshita, K. Tanaka, A. Ishizawa, H. Sakai, M. Nunami, Y. Ohtani, H. Yamada, M. Sato, M. Nakata, T. Tokuzawa, R. Yasuhara, Y. Takemura, I. Yamada, H. Funaba, K. Ida, M. Yoshinuma, T. Tsujimura, R. Seki, K. Ichiguchi, C. A. Michael

    Physical Review Letters   132 ( 23 )   235101   2024.6   ISSN:0031-9007 eISSN:1079-7114

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Physical Society (APS)  

    In this study, we discovered a turbulence transition in a large helical device. The turbulence level and turbulence-driven energy transport decrease to a specific transition density and increase above it. The ruling turbulences below and above the transition density were ion-temperature gradient (ITG) and resistive-interchange (RI) turbulences, consistent with the predictions of gyrokinetic theory and two-fluid MHD model, respectively. Isotope experiments on hydrogen (H) and deuterium (D) clarified the role of transitions. In the ITG regime, turbulence levels and energy transport were comparable in the H and D plasmas. In contrast, in the RI regime, they were clearly suppressed in the D plasma. The results provide crucial knowledge for understanding isotope effects and future optimization of stellarator and heliotron devices.

    Published by the American Physical Society 2024

    DOI: 10.1103/PhysRevLett.132.235101

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    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.132.235101/fulltext

  • Overview of Large Helical Device experiments of basic plasma physics for solving crucial issues in reaching burning plasma conditions

    K. Ida, M. Yoshinuma, M. Kobayashi, T. Kobayashi, N. Kenmochi, F. Nespoli, R.M. Magee, F. Warmer, A. Dinklage, A. Matsuyama, R. Sakamoto, T. Nasu, T. Tokuzawa, T. Kinoshita, K. Tanaka, N. Tamura, K. Nagaoka, M. Nishiura, Y. Takemura, K. Ogawa, G. Motojima, T. Oishi, Y. Morishita, J. Varela, W.H.J. Hayashi, M. Markl, H. Bouvain, Y. Liang, M. Leconte, D. Moseev, V.E. Moiseenko, C.G. Albert, I. Allfrey, A. Alonso, F.J. Arellano, N. Ashikawa, A. Azegami, L. Bardoczi, M. van Berkel, M. Beurskens, M.W. Binderbaue, A. Bortolon, S. Brezinsek, R. Bussiahn, A. Cappa, D. Carralero, I.C. Chan, J. Cheng, X. Dai, D.J. Den Hartog, C.P. Dhard, F. Ding, A. Ejiri, S. Ertmer, T. Fornal, K. Fujita, Y. Fujiwara, H. Funaba, L. Garcia, J.M. Garcia-Regana, I. Garcia-Cortés, I.E. Garkusha, D.A. Gates, Y. Ghai, E.P. Gilson, H. Gota, M. Goto, E.M. Green, V. Haak, S. Hamaguchi, K. Hanada, H. Hara, D. Hartmann, Y. Hayashi, T. Henning, C. Hidalgo, J. Hillairet, R. Hutton, T. Ido, H. Igami, K. Ikeda, S. Inagaki, A. Ishizawa, S. Ito, M. Isobe, Y. Isobe, M. Ivkovic, Z. Jiang, J. Jo, S. Kamio, H. Kasahara, D. Kato, Y. Katoh, Y. Kawachi, Y. Kawamoto, G. Kawamura, T. Kawate, Ye.O. Kazakov, V. Klumper, A. Knieps, W.H. Ko, S. Kobayashi, F. Koike, Yu.V. Kovtun, M. Kubkowska, S. Kubo, S.S.H. Lam, A. Langenberg, H. Laqua, S. Lazerson, J. Lestz, B. Li, L. Liao, Z. Lin, R. Lunsford, S. Masuzaki, H. Matsuura, K.J. McCarthy, D. Medina-Roque, O. Mitarai, A. Mollen, C. Moon, Y. Mori, T. Morisaki, S. Morita, K. Mukai, I. Murakami, S. Murakami, T. Murase, C.M. Muscatello, K. Nagasaki, D. Naujoks, H. Nakano, M. Nakata, Y. Narushima, A. Nagy, J.H. Nicolau, T. Nishizawa, S. Nishimoto, H. Nuga, M. Nunami, R. Ochoukov, S. Ohdachi, J. Ongena, M. Osakabe, N.A. Pablant, N. Panadero, B. Peterson, J. de la Riva Villén, J. Romazanov, J. Rosato, M. Rud, S. Sakakibara, H.A. Sakaue, H. Sakai, I. Sakon, M. Salewski, S. Sangaroon, S. Sereda, T. Stange, K. Saito, S. Satake, R. Seki, T. Seki, S. Sharapov, A. Shimizu, T. Shimozuma, G. Shivam, M. Shoji, D.A. Spong, H. Sugama, Z. Sun, C. Suzuki, Y. Suzuki, T. Tajima, E. Takada, H. Takahashi, K. Toi, Y. Tsuchibushi, N. Tsujii, K. Tsumori, T.I. Tsujimurai, G. Ueno, H. Uehara, J.L. Velasco, E. Wang, K.Y. Watanabe, T. Wauter, U. Wenzel, M. Yajima, H. Yamada, I. Yamada, K. Yanagihara, H. Yamaguchi, R. Yanai, R. Yasuhara, M. Yokoyama, Y. Yoshimura, M. Zarnstorff, M. Zhao, G.Q. Zhong, Q. Zhou, S. Ziaei

    Nuclear Fusion   64 ( 11 )   112009 - 112009   2024.8   ISSN:0029-5515 eISSN:1741-4326

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    Publishing type:Research paper (scientific journal)   Publisher:IOP Publishing  

    Abstract

    Recently, experiments on basic plasma physics issues for solving future problems in fusion energy have been performed on a Large Helical Device. There are several problems to be solved in future devices for fusion energy. Emerging issues in burning plasma are: alpha-channeling (ion heating by alpha particles), turbulence and transport in electron dominant heating helium ash exhaust, reduction of the divertor heat load. To solve these problems, understanding the basic plasma physics of (1) wave–particle interaction through (inverse) Landau damping, (2) characteristics of electron-scale (high-k) turbulence, (3) ion mixing and the isotope effect, and (4) turbulence spreading and detachment, is necessary. This overview discusses the experimental studies on these issues and turbulent transport in multi-ion plasma and other issues in the appendix.

    DOI: 10.1088/1741-4326/ad3a7a

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  • Improving Current Distribution Model for EBWCD using Flux Loops in QUEST

    Junyao Zhou, Hanada Kazuaki, Kuroda Kengoh, Onchi Takumi, Idei Hiroshi, Ikezoe Ryuya, Hasegawa Makoto, Nagashima Yoshihiko, Ido Takeshi, Kinoshita Toshiki

    Evergreen   11 ( 2 )   555 - 562   2024.6   ISSN:21890420 eISSN:24325953

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    Language:English   Publisher:Transdisciplinary Research and Education Center for Green Technologies, Kyushu University  

    During the early phase of tokamak plasma start-up prior to the formation of a closed magnetic surface, various plasma current profiles are expected to be observed. Especially, the noninductive current drive (CD) by the electron Bernstein wave (EBW) is likely to be the most dominant, and the current profile is expected to focus on a local area predicted by the theoretical model. In addition, the EBWCD direction could be affected by a horizontal magnetic field induced by a toroidal magnetic field coil and feed-through. The magnetic flux data cannot be fitted by using a previous model described by Yoshinaga23), and hence, this model needs improvement. Consequently, an improved model is introduced in this paper based on the theoretical prediction of EBWCD. This model can be applied to reproduce the complex plasma current profile accurately during the early phase of the tokamak plasma start-up.

    DOI: 10.5109/7183306

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  • Development of sweeping detector phase contrast imaging in Large Helical Device

    H. Sakai, K. Tanaka, T. Kinoshita

    Journal of Instrumentation   18 ( 12 )   C12019 - C12019   2023.12   ISSN:1748-0221 eISSN:1748-0221

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:IOP Publishing  

    Abstract

    Phase contrast imaging (PCI) has been used for the turbulence profile measurement in Large Helical Devices; however, it does not have sufficient spatial resolution owing to the small number of two-dimensional (2D) detector elements. Therefore, in this study, we limited the measurement target to steady-state plasmas and conduct a pseudo multichanneling of a 2D detector array by sweeping using a one-dimensional detector. This new system is called SD-PCI. SD-PCI needs two detectors, one is one-dimensional detector and the other is single channel detector. By selecting suitable detector and imaging magnification for target turbulence or device characteristics, SD-PCI demonstrates the potential capability and enhancements. The wavenumber spectra comparison from the correlation calculations of the simultaneous measurement of the actual plasma with conventional 2D-PCI and proposed SD-PCI shows that SD-PCI is as effective as 2D-PCI in spectral broadening. The simplicity of the proposed system is expected to be applicable to various devices. In this paper, the SD-PCI system was explained along with the initial results of the 2D wavenumber spectrum calculation, which was necessary for obtaining turbulence profile.

    DOI: 10.1088/1748-0221/18/12/c12019

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  • Absolute value measurement of ion-scale turbulence by two-dimensional phase contrast imaging in Large Helical Device

    T. Kinoshita, K. Tanaka, H. Sakai, R. Yanai, M. Nunami, C.A. Michael

    Journal of Instrumentation   18 ( 11 )   C11009 - C11009   2023.11   ISSN:1748-0221 eISSN:1748-0221

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    Abstract

    Absolute value measurements of turbulence amplitude in magnetically confined high-temperature plasmas can effectively explain turbulence-driven transport characteristics and their role in plasma confinements. Two-dimensional phase contrast imaging (2D-PCI) is a technique to evaluate the space-time spectrum of ion-scale electron density fluctuation. However, absolute value measurement of turbulence amplitude has not been conducted owing to the nonlinearity of the detector. In this study, the absolute measurement method proposed in the previous study is applied to turbulence measurement results in the large helical device. As a result, the localized turbulence amplitude at n<sub>e</sub> = 1.5 × 10<sup>19</sup> m<sup>-3</sup> is approximately 3.5 × 10<sup>15</sup> m<sup>-3</sup>, which is 0.02% of the electron density. In addition, the evaluated poloidal wavenumber spectrum is almost consistent, within a certain error range, the spectrum being calculated using a nonlinear gyrokinetic simulation. This result is the first to the best of our knowledge to quantitatively evaluate turbulence amplitudes measured by 2D-PCI and compare with simulations.

    DOI: 10.1088/1748-0221/18/11/c11009

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    Other Link: https://iopscience.iop.org/article/10.1088/1748-0221/18/11/C11009/pdf

    Repository Public URL: https://hdl.handle.net/2324/7174416

  • Investigation of turbulence transition and its threshold in LHD

    Kinoshita Toshiki, Tanaka Kenji, Yokoyama Tatsuya, Ishizawa Akihiro, Sakai Hikona

    2023.11

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  • Turbulence Transition and Its Role in Isotope Effects of LHD

    Kinoshita T., Tanaka K., Ishizawa A., Nunami M., Sakai H.

    2023.10

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    In this study, we discover a turbulence transition and its role in the isotope effects in the Large Helical Device (LHD). The turbulence levels and turbulence-driven transports decrease with an increase in the electron density to a specific density; however, they increase in regimes above the density. Density scan experiments and gyrokinetic/MHD simulations reveal that the observed ion-scale turbulence is the ion-temperature gradient (ITG) turbulence below the density and resistive-interchange (RI) above the density. Negligible isotope effects in the turbulences and transports of hydrogen (H) and deuterium (D) plasma were found in the ITG regime. However, clear isotope effects were observed in the RI regime. In the RI regime, the turbulences and transports were clearly suppressed, and the confinements were improved in D plasma. The reduction of the turbulence level in the RI regime of the D plasma is likely due to the heavier ion mass and lower resistivity in D plasma, which suppress the linear growth rate of RI turbulence.

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  • Absolute value measurement of ion-scale turbulence by 2D-PCI in LHD

    Kinoshita T., Tanaka K., Sakai H., Yanai R., Nunami M., Michael C. A.

    2023.9

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    Language:English  

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  • Observation of Interaction between Fast Ions and Turbulence in Large Helical Device

    Hikona SAKAI, Kenji TANAKA, Toshiki KINOSHITA, Kunihiro OGAWA

    Plasma and Fusion Research   18 ( 0 )   2402069 - 2402069   2023.9   ISSN:18806821 eISSN:18806821

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:The Japan Society of Plasma Science and Nuclear Fusion Research  

    <p>Systematic experiments were carried out in the 23rd Large Helical Device experiment campaign to explore the interaction between fast ions and ion-scale turbulence focusing on the impact of varying the power of the neutral beam (NB) injection. During the NB heating, two distinct phases of turbulence reduction were observed. The first phase was a transient reduction of about 10 msec immediately following the initiation of the NB injection. This reduction in turbulence was noticeable even while the electron density and temperature profiles remained nearly unchanged. The second phase involved a continuous reduction that maintained a lower turbulence level throughout the duration of the NB injection. The physics mechanisms underlying these phenomena are not fully understood yet. However, it is likely that two distinct processes of turbulence stabilization, each corresponding to the transient and continuous reduction phases, are at work due to the influence of the fast ions.</p>

    DOI: 10.1585/pfr.18.2402069

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  • Application of Digital Phase Analysis to Far-Infrared Laser Interferometer for the Large Helical Device

    Hikona SAKAI, Kenji TANAKA, Yuki TAKEMURA, Yasuhiko ITO, Tokihiko TOKUZAWA, Ryo YASUHARA, Hiyori UEHARA, Toshiki KINOSHITA, Tsuyoshi AKIYAMA, Kazuya NAKAYAMA, Kazuo KAWAHATA

    Plasma and Fusion Research   18 ( 0 )   1402062 - 1402062   2023.8   ISSN:18806821 eISSN:18806821

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:The Japan Society of Plasma Science and Nuclear Fusion Research  

    <p>A digital phase analysis technique was applied to a 119-m wavelength far-infrared (FIR) laser interferometer on the Large Helical Device (LHD). High-density plasma measurement without phase jumping was achieved, representing an improvement over measurements made using a conventional analog phase counter. Digital phase analysis became operational at a quarter of the threshold of the analog phase counter. The phase sensitivity was also improved using digital analysis because the noise level was reduced to approximately half that of the conventional analog phase counter. The improved phase sensitivity enabled measurement of small-amplitude fluctuations.</p>

    DOI: 10.1585/pfr.18.1402062

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  • A reduced-turbulence regime in the Large Helical Device upon injection of low-Z materials powders

    F. Nespoli, K. Tanaka, S. Masuzaki, N. Ashikawa, M. Shoji, E.P. Gilson, R. Lunsford, T. Oishi, K. Ida, M. Yoshinuma, Y. Takemura, T. Kinoshita, G. Motojima, M. Osakabe, N. Kenmochi, G. Kawamura, C. Suzuki, A. Nagy, A. Bortolon, N.A. Pablant, A. Mollen, N. Tamura, D.A. Gates, T. Morisaki

    Nuclear Fusion   63 ( 7 )   076001 - 076001   2023.5   ISSN:0029-5515 eISSN:1741-4326

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    Abstract

    Recently an improved confinement regime, characterized by reduced turbulent fluctuations has been observed in the Large Helical Device upon the injection of boron powder into the plasma (Nespoli et al 2022 Nat. Phys.18 350–56). In this article, we report in more detail the experimental observations of increased plasma temperature and the decrease of turbulent fluctuations across the plasma cross section, on an extended database. In particular, we compare powders of different materials (B, C, BN), finding similar temperature improvement and turbulence response for the three cases. Modeling of the powder penetration into the plasma and of neoclassical electric field and fluxes support the interpretation of the experimental results. Additionally, we report evidence of the temperature improvement increasing with powder injection rates and decreasing for both increasing density and heating power. Though, plasma turbulence response varies depending on the initial conditions of the plasma, making it difficult to draw an inclusive description of the phenomenon.

    DOI: 10.1088/1741-4326/acd465

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  • Development of Two-Color Laser Imaging Interferometer Using CO2 Laser and Quantum Cascade Laser in the Large Helical Device

    Toshiki KINOSHITA, Kenji TANAKA, Yuki TAKEMURA, Shota TAKESHIDA, Hikona SAKAI

    Plasma and Fusion Research   17 ( 0 )   1402107 - 1402107   2022.12   ISSN:18806821 eISSN:18806821

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:The Japan Society of Plasma Science and Nuclear Fusion Research  

    <p>CO<sub>2 </sub>laser interferometers are a promising option for high-density plasma measurements. However, in low- and middle-density measurements, noise due to mechanical vibrations is a serious problem. To remove this noise, we developed a two-color laser imaging interferometer using a CO<sub>2 </sub>laser and quantum cascade (QC) laser, called the CO<sub>2</sub>/QC laser imaging interferometer, through benchtop experiments and installed it in the Large Helical Device (LHD). Benchtop experiments provided optical design guidelines for the CO<sub>2</sub>/QC laser imaging interferometer to minimize the influence of the unstable output wavelength of the QC laser. The optical system in LHD was designed according to this guideline, and the vibration noise was successfully reduced to 2.80 × 10<sup>18 </sup>m<sup>-3</sup>. We also demonstrate measurement examples of hollowed and peaked electron density profiles evaluated using Abel inversion and macro-scale instability. This is the first study to present the measurement results of high-temperature plasma using a CO<sub>2</sub>/QC two-color laser interferometer. The study outcomes provide important insights for the development of two-color laser interferometers in future fusion devices.</p>

    DOI: 10.1585/pfr.17.1402107

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    Repository Public URL: https://hdl.handle.net/2324/7183303

  • Mixing of laser-induced plumes colliding in a background gas

    Keita Katayama, Toshiki Kinoshita, Ren Okada, Hiroshi Fukuoka, Takehito Yoshida, Minoru Yaga, Tamao Aoki-Matsumoto, Ikurou Umezu

    Applied Physics A   128 ( 11 )   2022.11

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    DOI: 10.1007/s00339-022-06136-1

  • Confinement improvement during detached phase with RMP application in deuterium plasmas of LHD

    M. Kobayashi, R. Seki, Y. Hayashi, T. Oishi, K. Tanaka, Y. Takemura, K. Ida, T. Kinoshita, K. Mukai, S. Morita, S. Masuzaki

    Nuclear Fusion   62 ( 5 )   056006 - 056006   2022.5

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    DOI: 10.1088/1741-4326/ac42f3

  • Turbulence Spreading into an Edge Stochastic Magnetic Layer Induced by Magnetic Fluctuation and Its Impact on Divertor Heat Load

    M. Kobayashi, K. Tanaka, K. Ida, Y. Hayashi, Y. Takemura, T. Kinoshita

    Physical Review Letters   128 ( 12 )   125001   2022.3   ISSN:0031-9007 eISSN:1079-7114

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  • Direct observation of the non-locality of non-diffusive counter-gradient electron thermal transport during the formation of hollow electron-temperature profiles in the Large Helical Device

    T. I. Tsujimura, T. Kobayashi, K. Tanaka, K. Ida, K. Nagaoka, M. Yoshinuma, I. Yamada, H. Funaba, R. Seki, S. Satake, T. Kinoshita, T. Tokuzawa, N. Kenmochi, H. Igami, K. Mukai, M. Goto, Y. Kawamoto

    Physics of Plasmas   29 ( 3 )   032504 - 032504   2022.3   ISSN:1070-664X eISSN:1089-7674

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    A heating source with off-axis electron cyclotron heating (ECH) alone produced a plasma with a quasi-steady-state hollow electron-temperature profile in the Large Helical Device. The clear formation of this quasi-steady-state hollow electron-temperature profile can be explained by adding the outward heat convection term to the diffusion term, as a simple model to describe the electron heat flux, using the energy conservation equation. In addition, we directly observed the non-locality of the non-diffusive (convective) contribution in transient electron thermal transport in the condition that power-modulated on-axis ECH was applied to the plasma sustained by off-axis ECH. The experimentally evaluated flux-gradient relation shows two different positive values of the electron heat flux at zero temperature gradient by going back and forth between positive and negative temperature gradient regions in the transport hysteresis phenomenon.

    DOI: 10.1063/5.0074351

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  • Observation of a reduced-turbulence regime with boron powder injection in a stellarator

    Nespoli, F; Masuzaki, S; Tanaka, K; Ashikawa, N; Shoji, M; Gilson, EP; Lunsford, R; Oishi, T; Ida, K; Yoshinuma, M; Takemura, Y; Kinoshita, T; Motojima, G; Kenmochi, N; Kawamura, G; Suzuki, C; Nagy, A; Bortolon, A; Pablant, NA; Mollen, A; Tamura, N; Gates, DA; Morisaki, T

    NATURE PHYSICS   18 ( 3 )   350 - +   2022.3   ISSN:1745-2473 eISSN:1745-2481

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    Publisher:Nature Physics  

    In state-of-the-art stellarators, turbulence is a major cause of the degradation of plasma confinement. To maximize confinement, which eventually determines the amount of nuclear fusion reactions, turbulent transport needs to be reduced. Here we report the observation of a confinement regime in a stellarator plasma that is characterized by increased confinement and reduced turbulent fluctuations. The transition to this regime is driven by the injection of submillimetric boron powder grains into the plasma. With the line-averaged electron density being kept constant, we observe a substantial increase of stored energy and electron and ion temperatures. At the same time, the amplitude of the plasma turbulent fluctuations is halved. While lower frequency fluctuations are damped, higher frequency modes in the range between 100 and 200 kHz are excited. We have observed this regime for different heating schemes, namely with both electron and ion cyclotron resonant radio frequencies and neutral beams, for both directions of the magnetic field and both hydrogen and deuterium plasmas.

    DOI: 10.1038/s41567-021-01460-4

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  • Steady-state sustainment of divertor detachment with multi-species impurity seeding in LHD

    Kiyofumi Mukai, Suguru Masuzaki, Yuki Hayashi, Tetsutaro Oishi, Chihiro Suzuki, Masahiro Kobayashi, Tokihiko Tokuzawa, Hirohiko Tanaka, Kenji Tanaka, Toshiki Kinoshita, Hikona Sakai, Byron Jay Peterson

    Nuclear Fusion   61 ( 12 )   2021.12

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    DOI: 10.1088/1741-4326/ac2bbc

  • Isotope effects on transport in LHD

    K Tanaka, K Nagaoka, K Ida, H Yamada, T Kobayashi, S Satake, M Nakata, T Kinoshita, Y Ohtani, T Tokuzawa, H Takahashi, F Warmer, K Mukai, S Murakami, R Sakamoto, H Nakano, M Osakabe, T Morisaki, M Nunami, T Tala, T Tsujimura, Y Takemura, M Yokoyama, R Seki, H Igami, Y Yoshimura, S Kubo, T Shimozuma, T Akiyama, I Yamada, R Yasuhara, H Funaba, M Yoshinuma, M Goto, T Oishi, S Morita, G Motojima, M Shoji, S Masuzaki, C A Michael, L N Vacheslavov

    Plasma Physics and Controlled Fusion   63 ( 9 )   094001 - 094001   2021.9

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    DOI: 10.1088/1361-6587/abffb6

  • Observation of a novel reduced-turbulence regime with boron powder injection in a stellarator

    Federico Nespoli, Suguru Masuzaki, Kenji Tanaka, Naoko Ashikawa, Mamoru Shoji, Erik Gilson, Robert Lunsford, Tetsutaro Oishi, Katsumi Ida, Mikirou Yoshinuma, Yuki Takemura, Toshiki Kinoshita, Gen Motojima, Naoki Kenmochi, Gakushi Kawamura, Chihiro Suzuki, Alex Nagy, Aless, ro Bortolon, Novimir Pablant, Albert Mollen, Naoki Tamura, David Gates, Tomohiro Morisaki

    2021.6

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    DOI: 10.21203/rs.3.rs-614131/v1

  • Determination of absolute turbulence amplitude by CO2 laser phase contrast imaging

    T. Kinoshita, T. Maki, K. Tanaka, Y. Takemura

    Journal of Instrumentation   15 ( 01 )   C01045 - C01045   2020.1

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

    DOI: 10.1088/1748-0221/15/01/c01045

    Repository Public URL: https://hdl.handle.net/2324/7183307

  • Extended investigations of isotope effects on ECRH plasma in LHD

    K Tanaka, M Nakata, Y Ohtani, T Tokuzawa, H Yamada, F Warmer, M Nunami, S Satake, T Tala, T Tsujimura, Y Takemura, T Kinoshita, H Takahashi, M Yokoyama, R Seki, H Igami, Y Yoshimura, S Kubo, T Shimozuma, T Akiyama, I Yamada, R Yasuhara, H Funaba, M Yoshinuma, K Ida, M Goto, G Motojima, M Shoji, S Masuzaki, C A Michael, L N Vacheslavov, M Osakabe, T Morisaki

    Plasma Physics and Controlled Fusion   62 ( 2 )   024006 - 024006   2019.12

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

    DOI: 10.1088/1361-6587/ab5bae

  • Isotope effects on energy, particle transport and turbulence in electron cyclotron resonant heating plasma of the Large Helical Device

    K. Tanaka, Y. Ohtani, M. Nakata, F. Warmer, T. Tsujimura, Y. Takemura, T. Kinoshita, H. Takahashi, M. Yokoyama, R. Seki, H. Igami, Y. Yoshimura, S. Kubo, T. Shimozuma, T. Tokuzawa, T. Akiyama, I. Yamada, R. Yasuhara, H. Funaba, M. Yoshinuma, K. Ida, M. Goto, G. Motojima, M. Shoji, S. Masuzaki, C. A. Michael, L. N. Vacheslavov, M. Osakabe, T. Morisaki

    Nuclear Fusion   59 ( 12 )   2019.10

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

    DOI: 10.1088/1741-4326/ab4237

  • Numerical Analysis of Behavior on Opposing Unsteady Supersonic Jets in a Flow Field with Shields

    Toshiki Kinoshita, Hiroshi Fukuoka, Ikurou Umezu

    Materials Science Forum   910   96 - 101   2018.1

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

    DOI: 10.4028/www.scientific.net/msf.910.96

  • Effect of counter shock wave on the expanding plume

    Keita Katayama, Yuki Horai, Hiroshi Fukuoka, Toshiki Kinoshita, Takehito Yoshida, Tamao Aoki, Ikurou Umezu

    Applied Physics A   124 ( 2 )   2018.1

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

    DOI: 10.1007/s00339-018-1577-6

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Presentations

  • Turbulence Transition and Its Role in Isotope Effects of LHD International conference

    @T. Kinoshita, @K. Tanaka, @A. Ishizawa, @M. Nunami, #H. Sakai

    29th Fusion Energy Conference  2023.10 

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    Event date: 2023.10

    Language:English   Presentation type:Oral presentation (general)  

    Country:United Kingdom  

    Repository Public URL: https://hdl.handle.net/2324/7183316

  • Investigation of turbulence transition and its threshold in LHD Invited International conference

    @Toshiki Kinoshita, @Kenji Tanaka, @Tatsuya Yokoyama, @Akihiro Ishizawa, #Hikona Sakai

    7th Asia-Pacific Conference on Plasma Physics  2023.11 

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    Event date: 2023.11

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

    Repository Public URL: https://hdl.handle.net/2324/7183327

  • Absolute value measurement of ion-scale turbulence by 2D-PCI in LHD International conference

    @T. Kinoshita @K. Tanaka #H. Sakai @R. Yanai @M. Nunami @C. A. Michael

    20th International Symposium on Laser-Aided Plasma Diagnostics  2023.9 

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    Event date: 2023.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

    Repository Public URL: https://hdl.handle.net/2324/7183309

Professional Memberships

  • プラズマ・核融合学会

  • 日本物理学会

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

Research Projects

  • 学術研究基盤LHD計画

    2024.5

  • 軸対称プラズマの閉じ込め性能のアスペクト比依存性の起源の解明

    Grant number:24K00613  2024.4 - 2028.3

    科学研究費助成事業  基盤研究(B)

    井戸 毅, 長谷川 真, 木下 稔基, 森高 外征雄, 中村 浩章

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    Grant type:Scientific research funding

    低アスペクト比(トーラス形状の大半径Rと小半径aの比: R /a)を持つ球状トカマクは基本的な磁場構造は標準的なトカマクと同じであるにもかかわらず、そのエネルギー閉じ込め時間の物理パラメータ依存性は、標準的なトカマクのそれと大きく異なっている。本研究は、アスペクト比を球状トカマクから標準的なトカマクの領域まで変化させることができるプラズマ生成手法を開発し、ここに静電乱流と電磁乱流の計測システムと数値シミュレーションシステムを導入することにより、乱流輸送の観点からプラズマ閉じ込めのアスペクト比依存性の物理機構の解明に取り組む。

    CiNii Research

  • LHDにおける揺動を抑制したプラズマオペレーションの実証

    2024.4 - 2025.3

    共同研究

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

  • ボロンパウダー入射実験における乱流抑制機構の理解 スーパーコンピューターの利用

    2024.4 - 2025.3

    共同研究

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

  • QUESTにおける輸送研究のためのマイクロ波反射計開発

    2024.4 - 2025.3

    共同研究

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

  • 装置間比較を通じた磁場閉じ込め高温プラズマの同位体効果の解明

    Grant number:21J12314  2021.4 - 2023.3

    科学研究費助成事業  特別研究員奨励費

    木下 稔基

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    Grant type:Scientific research funding

    将来の核融合炉で想定されている重水素・三重水素混合プラズマ性能予測する上で軽水素および重水素プラズマにおけるプラズマ性能の違い(同位体効果)や将来の核融合装置を設計する上で異なるプラズマの閉じ込め磁場構造におけるプラズマ性能の違い(磁場配位効果)に関する知見は必要不可欠である.特に熱・粒子輸送はプラズマの閉じ込め性能を決定するため重要である.本研究では主に大型ヘリカル装置(LHD)にて軽水素および重水素実験を行い,熱・粒子輸送の評価および輸送を駆動する乱流揺動の計測を行い,それらの同位体効果についての知見をえる.また,これらの結果について他の装置と比較し,磁場配位効果についても提言する.

    CiNii Research

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Class subject

  • プラズマ理工学演習

    2023.10 - 2024.3   Second semester

  • 総合理工学修士実験

    2023.4 - 2024.3   Full year

  • 総合理工学修士演習

    2023.4 - 2024.3   Full year