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Idomura, Yasuhiro
Europhysics Conference Abstracts (Internet), 45A, 4 Pages, 2021/06
This work presents the impacts of the hydrogen isotope mass and the normalized plasma size on confinement of hydrogen (H) and deuterium (D) plasmas dominated by ion temperature gradient driven turbulence. Numerical experiments of H and D plasmas with ion and electron heating conditions were conducted using the Gyrokinetic Toroidal 5D full- f Eulerian code GT5D. The energy confinement time in the ion heated numerical experiments was almost independent of isotope mass, and the energy confinement was determined mainly by the normalized plasma size or the plasma size divided by the ion gyro radius, indicating an impact of non-local transport. On the other hand, the electron heated numerical experiments showed a clear isotope mass dependency. In addition to the plasma size effect, the isotope mass dependency of the collisional energy transfer from electrons to ions changes the ion heat flux and the turbulence intensity, leading to the degradation of confinement in H plasmas. These results qualitatively agree with the hydrogen isotope scaling in experiments.
Hayashi, Nobuhiko; Honda, Mitsuru; Shiraishi, Junya; Miyata, Yoshiaki; Wakatsuki, Takuma; Hoshino, Kazuo; Toma, Mitsunori; Suzuki, Takahiro; Urano, Hajime; Shimizu, Katsuhiro; et al.
Europhysics Conference Abstracts (Internet), 39E, p.P5.145_1 - P5.145_4, 2015/06
Kikuchi, Mitsuru; Medvedev, S.*; Takizuka, Tomonori*; Fasoli, A.*; Wu, Y.*; Diamond, P. H.*; Duan, X.*; Kishimoto, Yasuaki*; Hanada, Kazuaki*; 41 of others*
Europhysics Conference Abstracts (Internet), 39E, p.P4.179_1 - P4.179_4, 2015/06
Power and particle control in fusion reactor is quite a challenge and we have studied the negative triangularity tokamak (NTT) as an innovative concept to reduce the transient ELM heat load and the quasi steady-state heat load. A double-null NTT is stable to ideal MHD modes for a reactor relevant bN 
3 while it is a magnetic hill configuration. In this paper, we report the configuration study of single-null NTT and its ideal MHD stability.
Wakatsuki, Takuma; Suzuki, Takahiro; Hayashi, Nobuhiko; Shiraishi, Junya; Ide, Shunsuke; Takase, Yuichi*
Europhysics Conference Abstracts (Internet), 39E, p.P5.144_1 - P5.144_4, 2015/06
Urano, Hajime; Aiba, Nobuyuki; Kamiya, Kensaku; Kamada, Yutaka; JT-60 Team
Europhysics Conference Abstracts (Internet), 39E, p.P5.146_1 - P5.146_4, 2015/06
no abstracts in English
Nakano, Tomohide; Shumack, A. E.*; Maggi, C.*; Reinke, M.*; Lawson, K. D.*; P
tterich, T.*; Brezinsek, S.*; Lipschultz, B.*; Matthews, G.*; Chernyshova, M.*; et al.
Europhysics Conference Abstracts (Internet), 38F, p.P1.019_1 - P1.019_4, 2014/06
no abstracts in English
Hosokawa, Masanari*; Loarte, A.*; Huijsmans, G.*; Takizuka, Tomonori*; Hayashi, Nobuhiko
Europhysics Conference Abstracts (Internet), 38F, p.P5.003_1 - P5.003_4, 2014/06
Garcia, J.*; Hayashi, Nobuhiko; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; Ide, Shunsuke; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime; JT-60 Team; et al.
Europhysics Conference Abstracts (Internet), 38F, p.P1.029_1 - P1.029_4, 2014/06
Urano, Hajime; Nakata, Motoki; Aiba, Nobuyuki; Kubo, Hirotaka; Honda, Mitsuru; Yoshida, Maiko; Hayashi, Nobuhiko; Kamada, Yutaka; JT-60 Team
Europhysics Conference Abstracts (Internet), 38F, p.P4.018_1 - P4.018_4, 2014/06
This paper reports the analysis result of heat transport and pedestal structure in H-mode plasmas with and without argon seeding on JT-60U.
Shimada, Michiya; Hirooka, Yoshihiko*; Zhou, H.*
Europhysics Conference Abstracts (Internet), 38F, p.O2.110_1 - O2.110_4, 2014/00
Tungsten is considered to be most promising candidate for divertor target material for fusion reactor. Although tungsten target can withstand the heat loads of ITER, the heat exhaust requirement for DEMO is much more demanding. Pulsive heat loads associated with disurption would melt the tungsten divertor target. Melting and subsequent resolidification will roughen the tungsten surface, significantly deteriorating the heat handling capability. Further, tungsten has a rather high DBTT (Ductile-Brittle-Transition temperature) of 400
C. Neutron irradiation would further increase the DBTT, which could result in cracks. In view of these issues, liquid metal divertor is proposed, which is actively circulated with the Lorentz force introduced through the electrodes in the liquid metal. A modest flow speed of 0.3 m/s seems to be adequate for the heat load exhaust of DEMO. A simple treatment of MHD equation in a cylindrical geometry suggests that the requirements on the current and voltage are modest if the ramp-up of current is made slowly (e.g. in a minute), implying that the this concept is worth further study.
Honda, Mitsuru; Satake, Shinsuke*; Suzuki, Yasuhiro*; Matsunaga, Go; Ide, Shunsuke; Yoshida, Maiko; Hayashi, Nobuhiko
Europhysics Conference Abstracts (Internet), 37D, p.P1.182_1 - P1.182_4, 2013/07
Polevoi, A. R.*; Hayashi, Nobuhiko; Kim, H. S.*; Kim, S. H.*; Koechl, F.*; Kukushkin, A. S.*; Leonov, V. M.*; Loarte, A.*; Medvedev, S. Yu.*; Murakami, Masakatsu*; et al.
Europhysics Conference Abstracts (Internet), 37D, p.P2.135_1 - P2.135_4, 2013/07
Suzuki, Takahiro; Hayashi, Nobuhiko; Urano, Hajime; Miyata, Yoshiaki; Honda, Mitsuru; Ide, Shunsuke; JT-60SA Team
Europhysics Conference Abstracts (Internet), 37D, p.P2.136_1 - P2.136_4, 2013/00
no abstracts in English
Giruzzi, G.*; Artaud, J. F.*; Joffrin, E.*; Garcia, J.*; Ide, Shunsuke; JT-60SA Research Plan Contributors; JT-60SA Team
Europhysics Conference Abstracts (Internet), 36F, p.P5.018_1 - P5.018_4, 2012/00
Aiba, Nobuyuki; Cooper, W.*; Gruber, R.*
Europhysics Conference Abstracts (Internet), 36F, p.P2.045_1 - P2.045_4, 2012/00
We developed a new numerical method for analyzing linear ideal MHD stability with higher-order finite element. Since the linear ideal MHD problem is a typical ill-posed problem from numerical viewpoints, a kind of numerical instability, called spectrum pollution, sometimes appears. About 30 years ago, a method realizing to suppress this numerical instability was developed, but this cannot fully suppress this. In fact, when the radial mesh number decreases, numerical instability appears. After revisiting this method, we found that the numerical integral method in this method is not appropriate for suppressing this instability. To fix this issue, we developed a new method with Gauss-Legendre quadrature, and realized to fully suppress numerical instability. This method can apply to the stability analysis with plasma rotation.
Garcia, J.*; Hayashi, Nobuhiko; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; Ide, Shunsuke; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime; JT-60 Team; et al.
Europhysics Conference Abstracts (Internet), 36F, p.P5.057_1 - P5.057_4, 2012/00
Honda, Mitsuru; Fukuyama, Atsushi*; Nakajima, Noriyoshi*
Europhysics Conference Abstracts (Internet), 36F, p.P5.014_1 - P5.014_4, 2012/00
Koga, J. K.; Bulanov, S. V.; Esirkepov, T. Z.; Pirozhkov, A. S.; Kando, Masaki; Rosanov, N. N.*
Europhysics Conference Abstracts (Internet), 36F, p.O5.214_1 - O5.214_4, 2012/00
Matsunaga, Go; Kamiya, Kensaku; Shinohara, Koji; Miyato, Naoaki; Kojima, Atsushi; Bierwage, A.; JT-60 Team
Europhysics Conference Abstracts (Internet), 36F, p.P2.062_1 - P2.062_4, 2012/00
Urano, Hajime; Takizuka, Tomonori*; Kikuchi, Mitsuru; Nakano, Tomohide; Fujita, Takaaki; Hayashi, Nobuhiko; Oyama, Naoyuki; Kamada, Yutaka; JT-60 Team
Europhysics Conference Abstracts (Internet), 36F, p.P1.016_1 - P1.016_4, 2012/00
Energy confinement properties for hydrogen and deuterium H-mode plasmas were examined in JT-60U. The energy confinement time became larger by a factor of 
1.2-1.3 for deuterium than for hydrogen at a given 
. When the plasma energy was fixed, the profiles of density and temperature became identical for both cases while higher heating power was required for hydrogen. The ion conductive heat flux for hydrogen became approximately two times that for deuterium. Hence, the ion heat diffusivity for hydrogen was higher than for deuterium. It was found that the ion-temperature-gradient scale length became smaller by a factor of 1.2 for deuterium than for hydrogen.
