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Kitayama, Yoshiharu; Terasaka, Yuta; Sato, Yuki; Torii, Tatsuo
Journal of Nuclear Engineering and Radiation Science, 7(4), p.042006_1 - 042006_7, 2021/10
Huang, B.*; Satake, Shinsuke*; Kanno, Ryutaro*; Sugama, Hideo*; Matsuoka, Seikichi
Physics of Plasmas, 24(2), p.022503_1 - 022503_19, 2017/02
Times Cited Count：11 Percentile：54.14(Physics, Fluids & Plasmas)The drift kinetic equation describes the collisional (neoclassical) transport in plasmas. Recently, a novel radially-local approximation of the drift kinetic equation, which is called the zero orbit width (ZOW) model, is proposed. In this work, as a numerical verification of the neoclassical transport based on the ZOW model, we perform a series of benchmarks of the neoclassical transport and the parallel flow in three helical magnetic configurations using various types of radially-local approximation models including the ZOW model. We found that the neoclassical transport of the ZOW model can reproduce that based on the other models when the radial electric field and thus the 
drift is large. Also, it is demonstrated that an unphysical large radial transport, which arises in the neoclassical transport of the other models when the drift is small and compared to the magnetic drift, can be mitigated in the ZOW model.
Sugama, Hideo*; Matsuoka, Seikichi; Satake, Shinsuke*; Kanno, Ryutaro*
Physics of Plasmas, 23(4), p.042502_1 - 042502_11, 2016/04
Times Cited Count：7 Percentile：32.55(Physics, Fluids & Plasmas)A novel radially local approximation of the drift kinetic equation is presented. The new drift kinetic equation that includes both 
and tangential magnetic drift terms is written in the conservative form and it has favorable properties for numerical simulation that any additional terms for particle and energy sources are unnecessary for obtaining stationary solutions under the radially local approximation. These solutions satisfy the intrinsic ambipolarity condition for neoclassical particle fluxes in the presence of quasisymmetry of the magnetic field strength. Also, another radially local drift kinetic equation is presented, from which the positive definiteness of entropy production due to neoclassical transport and Onsager symmetry of neoclassical transport coefficients are derived while it sacrifices the ambipolarity condition for neoclassical particle fluxes in axisymmetric and quasi-symmetric systems.
Laird, J. S.; Hirao, Toshio; Onoda, Shinobu; Ito, Hisayoshi
Journal of Applied Physics, 98(1), p.013530_1 - 013530_14, 2005/07
Times Cited Count：45 Percentile：80.59(Physics, Applied)no abstracts in English
Sakakibara, Satoru*; Kurihara, Kenichi
Purazuma, Kaku Yugo Gakkai-Shi, 80(5), p.364 - 371, 2004/05
This article presents recent progress in magnetic measurements at magnetic confinement systems. The drift-problem of the integrator used in magnetic measurements is one of the major problems for plasma control and estimation of equilibrium parameters in long-pulse operation. In addition, the durability of the sensors such as a magnetic probe, a flux loop, etc., under fusion neutron irradiation environments is also important. The present status of the developments of a long-pulse integrator and a magnetic sensor are reported.
Asakura, Nobuyuki; Takenaga, Hidenobu; Sakurai, Shinji; Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; Shimizu, Katsuhiro; Higashijima, Satoru; Kubo, Hirotaka
Nuclear Fusion, 44(4), p.503 - 512, 2004/04
Times Cited Count：73 Percentile：89.68(Physics, Fluids & Plasmas)The measurements of the SOL flow and plasma profiles both at the high-field-side (HFS) and low-field-side (LFS), for the first time, found out the SOL flow pattern and its driving mechanism. "Flow reversal" was found near the HFS and LFS separatrix of the main plasma for the ion ▽B drift direction towards the divertor. Radial profiles of the SOL flow were similar to those calculated numerically using the UEDGE code with the plasma drifts included although Mach numbers in measurements were faster than those obtained numerically. Particle fluxes towards the HFS and LFS divertors produced by the parallel SOL flow and Er
B drift flow were evaluated. The particle flux for the case of intense gas puff and divertor pump (puff and pump) was investigated, and it was found that both flow velocity and collisionality were enhanced, in particular, at HFS SOL. Drift flux in the private flux region was also evaluated, and important physics issues for the divertor design and operation, such as in-out asymmetries of the heat and particle fluxes, and control of impurity ions were investigated.
Asakura, Nobuyuki; Sakurai, Shinji; Itami, Kiyoshi; Naito, Osamu; Takenaga, Hidenobu; Higashijima, Satoru; Koide, Yoshihiko; Sakamoto, Yoshiteru; Kubo, Hirotaka; Porter, G. D.*
Journal of Nuclear Materials, 313-316, p.820 - 827, 2003/03
Times Cited Count：36 Percentile：89.58(Materials Science, Multidisciplinary)no abstracts in English
Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; Loarte, A.*; Asakura, Nobuyuki; Takenaga, Hidenobu; Matthews, G.*; Contributors to JET-EFDA Workprogramme*
Journal of Nuclear Materials, 313-316, p.1085 - 1088, 2003/03
Times Cited Count：24 Percentile：81.86(Materials Science, Multidisciplinary)no abstracts in English
Chankin, A. V.; Stangeby, P. C.*
Proceedings of 30th EPS Conference on Controlled Fusion and Plasma Physics (CD-ROM), 4 Pages, 2003/00
no abstracts in English
Asakura, Nobuyuki; Takenaga, Hidenobu; Sakurai, Shinji; Sakasai, Akira; Tamai, Hiroshi; Shimizu, Katsuhiro; Porter, G. D.*
Plasma Physics and Controlled Fusion, 44(10), p.2101 - 2119, 2002/10
Times Cited Count：21 Percentile：54.51(Physics, Fluids & Plasmas)no abstracts in English
Rewoldt, G.*; Hill, K. W.*; Nazikian, R. M.*; Tang, W. M.*; Shirai, Hiroshi; Sakamoto, Yoshiteru; Kishimoto, Yasuaki; Ide, Shunsuke; Fujita, Takaaki
Nuclear Fusion, 42(4), p.403 - 411, 2002/04
Times Cited Count：9 Percentile：30.39(Physics, Fluids & Plasmas)One class of internal transport barrier discharge in the JT-60U tokamak is characterized by two relatively flat regions of the pressure separated by a region with very large pressure gradient. Linear growth rates for toroidal drift type modes are calculated for discharges in this class, without and with sheared 
rotation effects. For cases with fully developed barriers, the results with rotation are consistent with a picture in which the radial electric field generated in part by the steep pressure gradient causes local stabilization, and thus reduction of the local anomalous transport, which allows the steep pressure gradient to persist. If rotation is omitted from the calculation for these cases, or if rotation is included for cases without barriers or with partially developed barriers, the unstable region spreads into the steep pressure gradient region.
Asakura, Nobuyuki; Loarte, A.*; Porter, G.*; Philipps, V.*; Lipschultz, B.*; Kallenbach, A.*; Matthews, G.*; Federici, G.*; Kukushkin, A.*; Mahdavi, A.*; et al.
IAEA-CN-94/CT/P-01, 5 Pages, 2002/00
Three important physics issues for the ITER divertor design and operation are summarized based on the experimental and numerical work from multi-machine database (JET, JT-60U, ASDEX Upgrade, DIII-D, Alcator C-Mod and TEXTOR). (i) The energy load associated with Type-I ELMs is of great concern for the lifetime of the ITER divertor target. In order to understand the physics base of the scaling models, the ELM heat and particle transport to the divertor is investigated. Convective transport during ELMs plays an important role in heat transport to the divertor. (ii) Determination of the SOL flow pattern and the driving mechanism has progressed experimentally and numerically. Influences of the drift effects on the SOL and divertor plasma transport were discussed. (iii) Characteristics of chemical yield at two different deposited carbon surfaces, i.e. erosion- and redeposition-dominated areas, have been studied. Progress of understanding the chemical erosion is reviewed.
Idomura, Yasuhiro; Tokuda, Shinji; Kishimoto, Yasuaki; Wakatani, Masahiro*
Nuclear Fusion, 41(4), p.437 - 445, 2001/04
Times Cited Count：13 Percentile：40.95(Physics, Fluids & Plasmas)no abstracts in English
Idomura, Yasuhiro
JAERI 1341, 91 Pages, 2001/01
no abstracts in English
Takizuka, Tomonori; Hosokawa, Masanari*
Contributions to Plasma Physics, 40(3-4), p.471 - 477, 2000/11
Times Cited Count：19 Percentile：51.35(Physics, Fluids & Plasmas)no abstracts in English
Kawashima, Hisato; Sato, Masayasu; Tsuzuki, Kazuhiro; Miura, Yukitoshi; Kimura, Haruyuki; Tani, Takashi; Ido, Tsuyoshi; Isei, Nobuaki; Ogawa, Toshihide; Uehara, Kazuya; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 76(6), p.585 - 592, 2000/06
no abstracts in English
Asakura, Nobuyuki; Sakurai, Shinji; Shimada, Michiya; Koide, Yoshihiko; Hosogane, Nobuyuki; Itami, Kiyoshi
Physical Review Letters, 84(14), p.3093 - 3096, 2000/04
Times Cited Count：65 Percentile：87.76(Physics, Multidisciplinary)no abstracts in English
Kimura, Haruyuki; Kawashima, Hisato; Tsuzuki, Kazuhiro; Sato, Masayasu; Miura, Yukitoshi; Isei, Nobuaki; Ido, Takeshi*; Ogawa, Toshihide; Uehara, Kazuya; JFT-2M Group
JAERI-Conf 2000-004, p.77 - 80, 2000/03
no abstracts in English
Kawamata, Yoichi; Kurihara, Kenichi
KEK Proceedings 99-16, p.137 - 140, 1999/11
no abstracts in English
*; Tokuda, Shinji; Wakatani, Masahiro*
Purazuma, Kaku Yugo Gakkai-Shi, 75(2), p.131 - 142, 1999/02
no abstracts in English
