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Matsumoto Yutaka

Faculty of Engineering　Applied Quantum Science and Engineering　Quantum Engineering for Life Science and MedicineAssistant Professor

Researcher basic information

■ Degree
  • 博士(工学), 北海道大学
■ URL
researchmap URLホームページURL■ Various IDs
J-Global ID■ Research Keywords and Fields
Research Keyword
  • 磁場閉じ込め
  • ビーム圧力
  • プラズマ・核融合
  • MHD平衡・安定性
  • ヘリカル
  • 非等方圧力
Research Field
  • Energy Engineering, Nuclear fusion
■ Educational Organization

Career

■ Career
Career
  • 2009
    北海道大学 大学院・工学研究科, 助教

Research activity information

■ Papers
  • Wavefront reconstruction for fractional lateral shear measurements using weighted integer shear averages
    Samia Heshmat; Satoshi Tomioka; Naoki Miyamoto; Yuji Yamauchi; Yutaka Matsumoto; Naoki Higashi
    Optics and Lasers in Engineering, Jun. 2026
    Scientific journal
  • Effects of the Broken Solenoidal Condition of a Perturbed Magnetic Field in a MHD Simulation for the LHD
    Takado Wataru; Matsumoto Yutaka; Watanabe Kiyomasa; Tomioka Satoshi; Oikawa Shun-ichi
    Meeting Abstracts of the Physical Society of Japan, 72.2, 132, 132, The Physical Society of Japan, 2017
    Japanese
  • Characteristics of magnetic island formation due to resistive interchange instability in helical plasma
    R. Ueda; K. Y. Watanabe; Y. Matsumoto; M. Itagaki; M. Sato; S. Oikawa
    PHYSICS OF PLASMAS, 21, 5, 052502, May 2014, [Peer-reviewed]
    English, Scientific journal
  • Effect of re-entering fast ions on NBI heating power in high-beta plasmas of the Large Helical Device
    Ryosuke Seki; Kiyomasa Watanabe; Hisamichi Funaba; Yasuhiro Suzuki; Yutaka Matsumoto; Kiyotaka Hamamatsu; Satoru Sakakibara; Satoshi Ohdachi
    NUCLEAR FUSION, 53, 6, 063016, Jun. 2013, [Peer-reviewed]
    English
  • Analysis Method for the Low-Order Resistive Interchange Instability in LHD with Stochastic Magnetic Field Line Structure
    UEDA Ryosuke; SATO Masahiko; WATANABE Kiyomasa; MATSUMOTO Yutaka; SUZUKI Yasuhiro; ITAGAKI Masafumi; OIKAWA Shun-ichi; TODO Yasushi
    Plasma Fusion Res (Web), 8, 2403157-2403157 (J-STAGE), 2403157, The Japan Society of Plasma Science and Nuclear Fusion Research, 2013
    English, Scientific journal, In Large Helical Device experiments, independent low-order magnetic fluctuations due to the resistive interchange mode are commonly observed; investigating the characteristics of this instability is our ultimate goal. Two new methods for analyzing the single low-order instability in the stochastic region are developed. One method investigates it by constructing the initial single-mode perturbation. The other method investigates it by constructing a reference surface outside the last closed flux surface. The reference surface is necessary for constructing the coordinates that are used to extract the Fourier mode in the stochastic field line structure.
  • Improved Three-Dimensional CCS Method Analysis for the Reconstruction of the Peripheral Magnetic Field Structure in a Finite Beta Helical Plasma
    ITAGAKI Masafumi; ISHIMARU Kenzo; MATSUMOTO Yutaka; WATANABE Kiyomasa; SEKI Ryosuke; SUZUKI Yasuhiro
    Plasma Fusion Res (Web), 8, 1402134-1402134 (J-STAGE), 1402134, The Japan Society of Plasma Science and Nuclear Fusion Research, 2013
    English, Scientific journal, In the previous 3D Cauchy-condition surface (CCS) method analysis to reconstruct the magnetic field profile in the Large Helical Device (LHD), one assumed an impractically large number of magnetic sensors, i.e., 440 field sensors and 126 flux loops. In the singular value decomposition (SVD) process employed in the CCS method, a gap is found in the magnitude of the singular values. The most accurate field results can be obtained if all the singular values smaller than the gap threshold are eliminated, independent of the number of boundary elements on the CCS and the number of sensors as well. With the reduction in the number of boundary elements, the required numbers of field sensors and flux loops are significantly reduced to 110 and 25, respectively, without losing the solution accuracy. They can be further reduced to 58 and 13 respectively if considering the symmetry of the field profile in the LHD. This result suggests the possibility of actual application to the LHD.
  • Use of a twisted 3D Cauchy condition surface to reconstruct the last closed magnetic surface in a non-axisymmetric fusion plasma
    Masafumi Itagaki; Gaku Okubo; Masayuki Akazawa; Yutaka Matsumoto; Kiyomasa Watanabe; Ryosuke Seki; Yasuhiro Suzuki
    PLASMA PHYSICS AND CONTROLLED FUSION, 54, 12, 125003.1-125003.18, Dec. 2012
    English, Scientific journal
  • Re-entering Fast Ion Effects on NBI Heating Power in High-Beta Plasmas of the Large Helical Device
    SEKI Ryosuke; WATANABE Kiyomasa; FUNABA Hisamichi; SUZUKI Yasuhiro; MATSUMOTO Yutaka; HAMAMATSU Kiyotaka; SAKAKIBARA Satoru; OHDACHI Satoshi
    Res Rep NIFS Ser, 1019, 21P, 17 Oct. 2011
    English
  • Effectiveness of GPGPU for solving the magnetohydrodynamics equations using the CIP-MOCCT method
    Ryosuke Ueda; Yutaka Matsumoto; Masafumi Itagaki; Shun-Ichi Oikawa
    Plasma and Fusion Research, 6, 1, 2401092-2401092 (J-STAGE), 2011
    English, Scientific journal
  • Application of Algebraic Approximation to Three Dimensional Multibody Coulomb Problem: Implementation of GPGPU
    Shun-ichi Oikawa; K. Higashi; Y. Matsumoto
    Plasma Fusion Res., 5, S2026, S2026, Japan Society of Plasma Science and Nuclear Fusion Research, 2010, [Peer-reviewed]
    English, Scientific journal, The algebraic model (ALG) proposed by the authors has sufficiently high accuracy in calculating the motion of a test particle with all the field particles at rest. When all the field particles are moving, however, the ALG has relatively poor prediction ability on the motion of the test particle initially at rest. Nonetheless, the ALG approximation gives a good results for the statistical quantities, such as variance of velocity changes or the scattering cross section, for a sufficiently large number of Monte Carlo trials. We have implemented a graphics processing unit (GPU) using NVIDIA's CUDA architecture into the ALG scheme for Coulomb multibody problems. For N=28-body problem, the ALG calculations on the GPU is several times faster than on a typical CPU. The achieved speedup ratios on an NVIDIA GTX-285 are 10.5 and 2500 against the ALG-CPU and the DIM-CPU, respectively both on an Intel Celeron @3.06 GHz.
  • Monte Carlo Study Based on a Real Coordinate System for Tangentially Injected High-Energy Particles in the Large Helical Device
    SEKI Ryosuke; MATSUMOTO Yutaka; SUZUKI Yasuhiro; WATANABE Kiyomasa; HAMAMATSU Kiyotaka; ITAGAKI Masafumi
    Plasma Fusion Res (Web), 5, 027-027 (J-STAGE), 27, The Japan Society of Plasma Science and Nuclear Fusion Research, 2010
    English, A new Monte Carlo code based on particle tracing using real coordinates has been developed to properly treat the re-entering particles that repeatedly pass in and out of the last closed flux surface (LCFS). The particle loss due to the charge-exchange reaction has also been taken into account in this code. We apply this new code to the analysis of high-energy particles produced by tangential neutral beams (NBs) of the large helical device (LHD). It is confirmed that reasonable solutions of distribution functions are obtained for particles produced by the tangential-NBs. It is also confirmed that the effect of the particle orbit and the charge-exchange loss on the distribution function is properly included. The shapes of the distribution functions of particles, produced by the tangential-NBs in two temperature cases (1 keV and 0.1 keV), are the same. It is found that the re-entering particles play an important role in the analyses of the distribution function of particles produced by the NBs.
  • Monte-Carlo Study Based on Real Coordinates for Perpendicularly Injected High-Energy Ions in the LHD High-Beta Plasma
    SEKI Ryosuke; MATSUMOTO Yutaka; SUZUKI Yasuhiro; WATANABE Kiyomasa; HAMAMATSU Kiyotaka; ITAGAKI Masafumi
    Plasma Fusion Res (Web), 5, 014-014 (J-STAGE), 14, The Japan Society of Plasma Science and Nuclear Fusion Research, 2010
    English, Scientific journal, We present a study of ions produced by the perpendicular neutral beam in the high-beta plasma of Large Helical Device (LHD) that uses the Monte-Carlo code based on orbit following in real coordinates with Coulomb collisions. For no neutrals outside the plasma, the results indicate that there are remarkable differences in the distribution functions that depend on whether the loss boundary is set on the vacuum vessel wall or on the last closed flux surface (LCFS). Also, for finite neutral density nH = 1018 m−3, we find that the minor radial profile of the distribution function slightly differs from that for the infinite neutral density case, which corresponds to the loss boundary being set at the LCFS.
  • Particle Orbit Analysis in the Finite Beta Plasma of the Large Helical Device using Real Coordinates
    SEKI Ryousuke; MATSUMOTO Yutaka; SUZUKI Yasuhiro; WATANABE Kiyomasa; ITAGAKI Masafumi
    Plasma Fusion Res (Web), 3, 016-016 (J-STAGE), 16, The Japan Society of Plasma Science and Nuclear Fusion Research, 2008
    English, Scientific journal, High-energy particles in a finite beta plasma of the Large Helical Device (LHD) are numerically traced in a real coordinate system. We investigate particle orbits by changing the beta value and/or the magnetic field strength. No significant difference is found in the particle orbit classifications between the vacuum magnetic field and the finite beta plasma cases. The deviation of a banana orbit from the flux surfaces strongly depends on the beta value, although the deviation of the orbit of a passing particle is independent of the beta value. In addition, the deviation of the orbit of the passing particle, rather than that of the banana-orbit particles, depends on the magnetic field strength. We also examine the effect of re-entering particles, which repeatedly pass in and out of the last closed flux surface, in the finite beta plasma of the LHD. It is found that the number of re-entering particles in the finite beta plasma is larger than that in the vacuum magnetic field. As a result, the role of reentering particles in the finite beta plasma of the LHD is more important than that in the vacuum magnetic field, and the effect of the charge-exchange reaction on particle confinement in the finite beta plasma is large.
  • Numerical Study of Resistive Magnetohydrodynamic Mode Structures in Typical Plasmas of the Large Helical Device
    MATSUMOTO Yutaka; WATANABE Kiyomasa; GARCIA Luis
    Res Rep NIFS-PROC Ser, 69(1), 340, 343, Jan. 2008
    English
  • Analysis of the Alpha Particle Orbits in the High Beta Plasma of the Large Helical Device
    SEKI Ryousuke; MATSUMOTO Yutaka; SUZUKI Yasuhiro; WATANABE Kiyomasa; ITAGAKI Masafumi
    Res Rep NIFS-PROC Ser, 69(1), 387, 390, Jan. 2008
    English
  • Magnetic field structure and confinement of energetic particles in the LHD
    T Watanabe; Y Matsumoto; M Hishiki; S Oikawa; H Hojo; M Shoji; S Masuzaki; R Kumazawa; K Saito; T Seki; T Mutoh; A Komori
    NUCLEAR FUSION, 46, 2, 291, 305, Feb. 2006, [Peer-reviewed]
    English, Scientific journal
  • Particle orbit analysis under the ion cyclotron range of frequency heating in the large helical device
    Y Matsumoto; T Nagaura; S Oikawa; T Watanabe
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 43, 1, 332, 341, Jan. 2004, [Peer-reviewed]
    English
  • Ignition Condition for p-11B Reactor with LHD Type Magnetic Field Configuration
    T. Watanabe; Y. Matsumoto; M. Hishiki; S. Oikawa; H. Hojo
    J. Plasma Fusion Res. SERIES, 6, 630, 633, プラズマ・核融合学会, 2004, [Peer-reviewed]
    English, Scientific journal, Proton-Boron fusion reactor (p-^11B reactor) might be able to be achieved by the combination of the LHD type magnetic field configuration and the ion cyclotron range of frequency (ICRF) heating scheme of protons. The LHD magnetic field has the excellent ability for the high energy particle confinements. This characteristic is studied by numerical computations of high energetic particles in the LHD magnetic field where the strong ICRF field is applied. It is shown by the Langevin equation analysis that the steady state distribution function of ICRF heated proton becomes to the quasilinear plateau distribution function (QPDF). The fusion reaction rate of p-11B is calculated for QPDF protons and studied the ignition condition. It is found that the ignition condition becomes possible to be satisfied if effective temperature of proton is of the order of 300 keV and nτ >~ 10^22 s/m3.
  • Field line and particle orbit analysis in the periphery of the large helical device
    Y Matsumoto; S Oikawa; T Watanabe
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 71, 7, 1684, 1693, Jul. 2002, [Peer-reviewed]
    English
  • The divertor plasma characteristics in the Large Helical Device
    MASUZAKI S; MORISAKI T; OHYABU N; KOMORI A; SUZUKI H; NODA N; KUBOTA Y; SAKAMOTO R; MATSUMOTO Y
    Nuclear Fusion, 42, 6, 750, 758, 2002, [Peer-reviewed]
  • Helical divertor and the Local Island Divertor in the Large Helical Device
    MASUZAKI S; MORISAKI T; KOMORI A; OHYABU N; SUZUKI H; KUBOTA Y; WATANABE T; MATSUMOTO Y; MOTOJIMA O
    Plasma Physics and Controlled Fusion, 44, 6, 795, 809, 2002, [Peer-reviewed]
  • Review of initial experimental results of the PSI studies in the large helical device
    S Masuzaki; K Akaishi; H Funaba; M Goto; K Ida; S Inagaki; N Inoue; K Kawahata; A Komori; Y Kubota; T Morisaki; S Morita; Y Nakamura; K Narihara; K Nishimura; N Noda; N Ohyabu; B.J Peterson; A Sagara; R Sakamoto; K Sato; M Shoji; H Suzuki; Y Takeiri; K Tanaka; T Tokuzawa; T Watanabe; K Tsuzuki; T Hino; Y Matsumoto; S Kado; O Motojima
    Journal of Nuclear Materials, 290/293, 12, 18, Elsevier BV, 2001, [Peer-reviewed]
    Scientific journal
  • LHD Type Proton-Boron Reactor and the Control of Its Peripheral Potential Structure
    Y. Matsumoto; T. Nagaura; Y. Itoh; S. Oikawa; T. Watanabe
    J. Plasma Fusion Res. SERIES, 4, 422, 426, 2001, [Peer-reviewed]
    English
  • Mirror Confined Plasma in the Large Helical Device
    Y. Matsumoto; T. Nagaura; S. Oikawa; T. Watanabe
    Trans. Fusion Tech., 39, 309, 312, 2001, [Peer-reviewed]
    English, Scientific journal
  • Analytical model for peripheral plasma of LHD
    T. Watanabe; Yutaka Matsumoto; Shun-ichi Oikawa
    J. Advanced Science, 11, 4, 211, 218, Society of Advanced Science, 1999, [Peer-reviewed]
    English, It is shown details of magnetic filed structure of LHD and that the connection length of divertor filed lines are of the order of 10km. Based on these characteristics of the peripheral magnetic filed structure, it is proposed an analytical model for divertor plasma of LHD. Heat flow in chaotic field line region is analyzed and criterion for detached divertor plasma is obtained.
■ Other Activities and Achievements
■ Syllabus
  • コンピュータ演習, 2024年, 学士課程, 工学部
■ Research Themes
  • Three-dimensional density distribution mesurement of spieces of mixtured gas by shearing interferometry with multi-wavelength light
    Grants-in-Aid for Scientific Research
    01 Apr. 2022 - 31 Mar. 2025
    富岡 智; 山内 有二; 宮本 直樹; 松本 裕
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22K04117
  • Three-dimensional refractive index measurement system using shear interferometer
    Grants-in-Aid for Scientific Research
    01 Apr. 2018 - 31 Mar. 2021
    Tomioka Satoshi
    In order to measure the three-dimensional refractive index distribution, a coupling method of interferometer and computed tomography can be used. As the interferometer to measure delay of wavefront due to object from different incident angles, we adopted a shearing interferometer, which always satisfies interference condition during changing incident angle since the shearing interferometer does not use a reference wave. We demonstrated that interferograms obtained with the shearing interferometer are not affected by vibration caused by changing of the incident direction. In addition, we measured the three-dimensional distribution of the refractive index of the gas near the candle flame, and the reconstructed result was qualitative agreed.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18K04158
  • Establishment and practical use of the diagnosis technique to identify the non-axisymmetric fusion plasma boundary shape in the peripheral magnetic field region
    Grants-in-Aid for Scientific Research
    01 Apr. 2012 - 31 Mar. 2015
    ITAGAKI Masafumi; MATSUMOTO Yutaka
    The Cauchy condition surface (CCS) method, which identifies the plasma boundary shape using external magnetic sensor signals, has been applied not only to axisymmetric tokamaks but also to the LHD, a non-axisymmetric helical device. Using the twisted CCS, the numerical accuracy in the reconstructed field has been improved. In the singular value (SV) decomposition process employed in the CCS method, a gap is found in the SVs. If all the SVs smaller than the gap threshold are eliminated, the required number of sensors can be significantly reduced without losing the solution accuracy.
    For some cases in the CCS analyses the effect of eddy current on the vacuum vessel (VV) cannot be neglected. To overcome this difficulty, boundary integrals of the eddy current along the VV are added to the CCS method formulation. The capability of the method is demonstrated for the RELAX device. The above techniques developed in the present series of works are applicable to many fusion devices.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 24561019
  • Effects of beam pressure on the MHD equilibria and stabilities in high beta helical plasmas
    Grants-in-Aid for Scientific Research
    2006 - 2009
    WATANABE Kiyomasa; SAKAKIBARA Satoru; OSAKABE Masaki; NAGAOKA Kenichi; SUZUKI Yasuhiro; MATSUMOTO Yutaka; GOTO Motoshi; SDEKI Ryouske; COOPER W.A.; PUSTOVITOV V.
    A probe to measure the particle and heat flux was designed and installed in a helical device, and it is applied to measure the heat flux from the reentering fast ions. The distribution function analyzing code of the fast ions in the high beta helical plasmas was developed, and it is applied to the evaluation of the beam pressure profile and its anisotropy induced by the neutral beam injection. The dependence of the magnetic axis shift on the pressure anisotropy was evaluated by the magnetic probe signal based on the calibration with the Monte-Carlo method, and its results are studied trough the comparison with some theoretical models.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), National Institute for Fusion Science, 18360445