Refine your search:     
Report No.
 - 
Search Results: Records 1-16 displayed on this page of 16
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Assessment of operational space for long-pulse scenarios in ITER

Polevoi, A. R.*; Loarte, A.*; Hayashi, Nobuhiko; Kim, H. S.*; Kim, S. H.*; Koechl, F.*; Kukushkin, A. S.*; Leonov, V. M.*; Medvedev, S. Yu.*; Murakami, Masakatsu*; et al.

Nuclear Fusion, 55(6), p.063019_1 - 063019_8, 2015/05

 Times Cited Count:23 Percentile:13.62(Physics, Fluids & Plasmas)

Journal Articles

Free boundary equilibrium in 3D tokamaks with toroidal rotation

Cooper, W. A.*; Brunetti, D.*; Faustin, J. M.*; Graves, J. P.*; Pfefferl$'e$, D.*; Raghunathan, M.*; Sauter, O.*; Tran, T. M.*; Chapman, I. T.*; Ham, C. J.*; et al.

Nuclear Fusion, 55(6), p.063032_1 - 063032_8, 2015/05

 Times Cited Count:1 Percentile:93.32(Physics, Fluids & Plasmas)

An approximate model for a single fluid 3D MHD equilibrium with pure isothermal toroidal flow with imposed nested magnetic flux surfaces is proposed. It recovers the rigorous toroidal rotation equilibrium description in the axisymmetric limit. The approximation is valid under conditions of nearly rigid or vanishing toroidal rotation in regions with 3D deformation of the equilibrium flux surfaces. Bifurcated helical core equilibrium simulations of long-lived modes in the MAST device demonstrate that the magnetic structure is only weakly affected by the flow but that the 3D pressure distortion is important. The pressure is displaced away from the major axis and therefore is not as noticeably helically deformed as the toroidal magnetic flux under the subsonic flow conditions. Fast particle confinement is investigated with the VENUS code. In the presence of toroidal flow, the drift orbit equations depend on the electrostatic potential associated with the rotation and quasineutrality at lowest order in Larmor radius. When the equilibrium has 3D deformations, geometrical terms appear from the evaluation of Ohm's Law that considerably complicates the description of fast particle confinement.

Journal Articles

Multi-parameter measurement using finite electron temperature effect on laser polarimetry for burning plasma reactor

Imazawa, Ryota; Kawano, Yasunori; Itami, Kiyoshi

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 6 Pages, 2014/10

no abstracts in English

Journal Articles

Development of tungsten monoblock technology for ITER full-tungsten divertor in Japan

Seki, Yohji; Ezato, Koichiro; Suzuki, Satoshi; Yokoyama, Kenji; Mori, Kensuke; Hirai, Takeshi*; Escourbiac, F.*; Kuznetsov, V.*

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Journal Articles

Integrated modeling of toroidal rotation with the 3D non-local drift-kinetic code and boundary models for JT-60U analyses and predictive simulations

Honda, Mitsuru; Satake, Shinsuke*; Suzuki, Yasuhiro*; Yoshida, Maiko; Hayashi, Nobuhiko; Kamiya, Kensaku; Matsuyama, Akinobu; Shinohara, Koji; Matsunaga, Go; Nakata, Motoki; et al.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Journal Articles

Extension of kinetic-magnetohydrodynamic model to include toroidal rotation shear effect and its application to stability analysis of resistive wall modes

Shiraishi, Junya; Miyato, Naoaki; Matsunaga, Go; Honda, Mitsuru; Hayashi, Nobuhiko; Ide, Shunsuke

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Extension of the kinetic-magnetohydrodynamic (MHD) model is presented to include toroidal rotation shear effect for the first time. The sheared rotation is introduced through generalization of the guiding center Lagrangian, yielding two additional terms in a quadratic form of mode-particle resonance. Additionally, another new term is introduced by using the equilibrium distribution function with rotation effect. These three terms are overlooked in conventional models. The new model is applied to stability analysis of resistive wall modes (RWMs) successfully. Numerical results show that the rotation shear reduces RWM growth rates further, which is consistent with experimental results.

Journal Articles

Studies of impurity seeding and divertor power handling in fusion reactor

Hoshino, Kazuo; Asakura, Nobuyuki; Shimizu, Katsuhiro; Tokunaga, Shinsuke

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 6 Pages, 2014/10

Journal Articles

Development of divertor simulation research in the GAMMA 10/PDX tandem mirror

Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Journal Articles

Multi-time-scale energetic particle dynamics in JT-60U simulated with MHD activity, sources and collisions

Bierwage, A.; Shinohara, Koji; Todo, Yasushi*; Yagi, Masatoshi

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Journal Articles

Analysis of accident scenarios of a water-cooled tokamak DEMO

Nakamura, Makoto; Ibano, Kenzo*; Tobita, Kenji; Someya, Yoji; Tanigawa, Hisashi; Gulden, W.*; Ogawa, Yuichi*

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

Of late in Japan, a design study has been undertaken of a tokamak fusion DEMO with pressurized water coolant and solid pebble bed breeding blanket, but safety characteristics of this type of DEMO have not been well examined. In this paper, thermohydraulics analysis of in-vessel and ex-vessel loss-of-coolant accidents of a water-cooled tokamak DEMO is reported. Safety characteristics of water-cooled DEMO, particularly possible loads onto confinement barriers, are discussed based on the thermohydraulics analysis results. Measures to reduce such loads are also proposed.

Journal Articles

MHD instability excited by interplay between resistive wall mode and stable MHD modes in rotating tokamak plasmas

Aiba, Nobuyuki; Hirota, Makoto*; Matsuyama, Akinobu; Shiraishi, Junya; Bierwage, A.

Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10

A mechanism exciting magnetohydrodynamic (MHD) instabilities in rotating tokamak plasmas is found numerically for the first time. This mechanism is the interplay between a resistive wall mode (RWM) and a stable MHD mode. When the plasma has a stable discrete eigenmode, a reversed shear Alfv$'e$n eigenmode (RSAE) for example, a MHD mode is destabilized when plasma equilibrium rotation frequency is similar to the frequency of this stable eigenmode in a static equilibrium. This destabilization is also observed even when the eigenmode couples with Alfv$'e$n continua. This result suggests that for steady state high beta tokamaks, like DEMO, it is necessary to shape the safety factor profile in such a way that no stable eigenmode exists in the band of rotation frequency.

Oral presentation

Physics and engineering studies of the advanced divertor for a fusion reactor

Asakura, Nobuyuki; Hoshino, Kazuo; Uto, Hiroyasu; Shinya, Kichiro*; Tokunaga, Shinsuke; Shimizu, Katsuhiro; Someya, Yoji; Tobita, Kenji; Ono, Noriyasu*

no journal, , 

A short super-X divertor is proposed as a new option for fusion divertor, where field line length from the divertor null to the outer target (L//div) was largely increased (more than two times) in a similar size of conventional divertor. Physics and engineering design studies have progressed. Minimal number of the divertor coils (1 or 2) were installed inside the toroidal field coil (TFC), i.e. interlink-winding (interlink). Arrangement of the poloidal field coils (PFCs) and their currents were determined, taking into account of the engineering design such as vacuum vessel and the neutron shield structures, and maintenance scenario of the divertor and blankets. Divertor plasma simulation showed that large radiation region is produced between the super-X null and the target, and the plasma temperature becomes low (1-2 eV) both at the inner and outer divertors, i.e. fully detached plasma was obtained efficiently.

Oral presentation

Development of DC ultra-high voltage insulation technology for ITER NBI

Tobari, Hiroyuki; Hanada, Masaya; Watanabe, Kazuhiro; Kashiwagi, Mieko; Kojima, Atsushi; Dairaku, Masayuki; Seki, Norikatsu; Abe, Hiroyuki; Umeda, Naotaka; Yamanaka, Haruhiko; et al.

no journal, , 

Progress on technical development on ITER and JT-60SA neutral beam injector (NBI) were reported. In development of a 1 MV insulating transformer for ITER NB power supply, a bushing extracting 1 MV required a huge insulator that was impossible to manufacture. To solve this issue, a composite bushing with FRP tube and a small condenser bushing with insulation gas was newly developed. In development the HV bushing as an insulating feed through, voltage holding in large cylindrical electrodes inside the HV bushing was investigated. The scaling for vacuum insulation design of large cylindrical electrodes was obtained. Toward long pulse production and acceleration of negative ion beam, active control system of plasma grid temperature and a new extractor consisting of the extraction grid with high water cooling capability and aperture offset were developed. As a result, 15 negative ion beam has been achieved for 100 s. Also beam energy density has been increased two orders of magnitude.

Oral presentation

Evaluation of Lithium Target Facility of IFMIF in IFMIF/EVEDA Project

Wakai, Eiichi; Kanemura, Takuji; Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi; Micciche, G.*; Heidinger, R.*; Knaster, J.*; Sugimoto, Masayoshi

no journal, , 

Oral presentation

Prototype development of the ITER EC system with 170 GHz gyrotron

Oda, Yasuhisa; Kajiwara, Ken; Ikeda, Ryosuke; Oshima, Katsumi; Hayashi, Kazuo*; Takahashi, Koji; Sakamoto, Keishi; Purohit, D.*; Gandini, F.*; Omori, Toshimichi*; et al.

no journal, , 

16 (Records 1-16 displayed on this page)
  • 1