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Kobayashi, Masato*; Saito, Masahiko*; Iwatani, Takafumi*; Nakayama, Masashi; Tanai, Kenji; Fujita, Tomoo; Asano, Hidekazu*
JAEA-Research 2015-018, 14 Pages, 2015/12
JAEA-Research-2015-018.pdf:5.43MB
JAEA and RWMC concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work based on the agreement. JAEA have been carrying out the Horonobe URL Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, The Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste disposal since 2008, to enhance public's understanding to the geological disposal of HLW, e.g. using underground facility. RWMC received an order of the project in fiscal year 2014 continuing since fiscal year 2008. Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing since fiscal year 2008. This report summarizes the results of the research on engineering technology carried out in this collaboration work in fiscal year 2014.
analyses with ferromagnetic and plasma rotation effects and wall geometry for a high steady state tokamakKurita, Genichi; Bialek, J.*; Tsuda, Takashi; Azumi, Masafumi*; Ishida, Shinichi; Navratil, G. A.*; Sakurai, Shinji; Tamai, Hiroshi; Matsukawa, Makoto; Ozeki, Takahisa; et al.
Nuclear Fusion, 46(2), p.383 - 390, 2006/02
Times Cited Count：9 Percentile：30.53(Physics, Fluids & Plasmas)It is shown that critical beta is decreased by ferromagnetic effect by about 8% for 
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2, and denoting the permeability of ferromagnetic wall and vacuum, respectively, for tokamak of aspect ratio 3. The existence of the stability window for resistive wall mode opened by both effects of the toroidal plasma rotation and the plasma dissipation, which was not observed for high aspect ratio tokamak, is found for tokamak of aspect ratio 3. The effect of ferromagnetism on them is also investigated. The critical beta analyses of NCT (National Centralized Tokamak) plasma using VALEN code are started with stabilizing plate and vacuum vessel geometry with finite resistivity, and the results for passive effect of stabilizing plate are obtained. The calculations including stabilizing effect of the vacuum-vessel and also active feedback control are also performed for present design of NCT plasma.
Matsukawa, Makoto; JT-60SC Design Team
IEEE Transactions on Applied Superconductivity, 14(2), p.1399 - 1404, 2004/06
Times Cited Count：4 Percentile：28.43(Engineering, Electrical & Electronic)no abstracts in English
Zohm, H.*; Gantenbein, G.*; Isayama, Akihiko; Keller, A.*; La Haye, R. J.*; Maraschek, M.*; M
ck, A.*; Nagasaki, Kazunobu*; Pinches, S. D.*; Strait, E. J.*
Plasma Physics and Controlled Fusion, 45(12A), p.A163 - A173, 2003/12
Times Cited Count：27 Percentile：62.00(Physics, Fluids & Plasmas)A review of magnetohydrodynamic limits to tokamak operation in terms of current, density and pressure is given. Although the current and density limits in a tokamak usually lead to disruptive termination of the discharge, it is argued that these can be avoided by staying away from the respective limits. This is especially true since operation close to these limits is not really desirable, due to the decreased confinement at very high density and the high disruptivity at low q. On the other hand, the limit to plasma pressure set by neoclassical tearing modes (NTMs) and resistive wall modes (RWMs) is too low to guarantee economic operation of future fusion reactors. Therefore, active control of these two instabilities is now being studied. Noticeable progress has been made by NTM stabilization with ECCD. Avoidance of NTMs and RWMs by tailoring sawteeth and spinning the plasma, shows promising results. Also, experiments on direct RWM stabilization by active coils are showing their first encouraging results.
Kurita, Genichi; Tsuda, Takashi; Azumi, Masafumi; Ishida, Shinichi; Takeji, Satoru*; Sakasai, Akira; Matsukawa, Makoto; Ozeki, Takahisa; Kikuchi, Mitsuru
Nuclear Fusion, 43(9), p.949 - 954, 2003/09
Times Cited Count：31 Percentile：66.61(Physics, Fluids & Plasmas)In order to improve economic and environmental suitability of tokamak fusion reactors, both the accomplishment of high beta plasmas and the practical use of low activation materials to reduce the amount of radioactive waste are crucially important. Low radio-activation ferritic steel is considered as a most promising candidate for structural material in DEMO reactors, and there is the possibility of reduction of critical beta value by the deterioration of MHD stability due to ferromagnetism of ferritic steel. This paper investigates the effect of ferromagnetism with plasma flow on the beta limit of tokamak plasma by carrying out MHD stability analyses including ferromagnetic and plasma flow effects.
Takeji, Satoru; Isayama, Akihiko; Ozeki, Takahisa; Tokuda, Shinji; Ishii, Yasutomo; Oikawa, Toshihiro; Ishida, Shinichi; Kamada, Yutaka; Neyatani, Yuzuru; Yoshino, Ryuji; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.278 - 297, 2002/09
Times Cited Count：7 Percentile：3.03(Nuclear Science & Technology)no abstracts in English
