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Nakamoto, Tatsushi*; Idesaki, Akira; Morishita, Norio; Ito, Hisayoshi; Kamiya, Tomihiro; Kimura, Nobuhiro*; Makida, Yasuhiro*; Ogitsu, Toru*; Ohata, Hirokatsu*; Yamamoto, Akira*
AIP Conference Proceedings 824, p.225 - 232, 2006/03
Radiation resistance with respect to mechanical properties of organic materials used in the superconducting magnets for the 50 GeV - 750 kW proton beam line for the J-PARC neutrino experiment was studied. Specimens cooled at liquid nitrogen temperature of 77 K were irradiated by gamma rays beyond 10 MGy. The flexural strength of glass-fiber reinforced plastics (GFRPs), the tear strength of polyimide films and the tensile lap-shear strength of adhesive films were evaluated. It was verified that the organic materials used in the superconducting magnet have a sufficient radiation resistance, and the degradation of their mechanical properties after 10 years operation was estimated to be negligible.
Nishimura, Arata*; Muroga, Takeo*; Takeuchi, Takao*; Nishitani, Takeo; Morioka, Atsuhiko
Fusion Engineering and Design, 81(8-14), p.1675 - 1681, 2006/02
Times Cited Count：3 Percentile：24.11(Nuclear Science & Technology)In a fusion reactor plant, a neutral beam injector (NBI) will be operated for a long time, and it will allow neutron streaming from NBI ports to outside of the plasma vacuum vessel. It requires the superconducting magnet to develop nuclear technology to produce stable magnetic field and to reduce activation of the magnet components. In this report, the back ground of the necessity and the contents of the nuclear technology of the superconducting magnets for fusion application are discussed and some typical investigation results are presented, which are the neutron irradiation effect on Nb
Sn wire, the development of low activation superconducting wire, and the design concept to reduce nuclear heating and nuclear transformation by streaming. In addition, recent activities in high energy particle physics are introduced and potential ripple effect of the technology of the superconducting magnets is described briefly.
Ishio, Kotaro*; Nakajima, Hideo
Tetsu To Hagane, 92(2), p.90 - 96, 2006/02
no abstracts in English
Ishio, Kotaro*; Hamada, Kazuya; Nakajima, Hideo
Tetsu To Hagane, 92(1), p.30 - 35, 2006/01
no abstracts in English
Yamauchi, Michinori*; Nishitani, Takeo; Nishio, Satoshi
Denki Gakkai Rombunshi, A, 125(11), p.943 - 946, 2005/11
Considering the geometrical characteristics of tokamak reactors with low aspect ratio, a basic neutronics strategy was derived to construct the inboard structure mainly for neutron shielding and produce enough tritium in the outboard blanket. The designs for optimal inboard shield were surveyed and necessary thickness was estimated to make the neutron flux low enough on the super-conducting magnet. In addition, the outer blanket designs were studied to attain the tritium breeding ratio (TBR) large enough for a self-sustaining fusion reactor on the basis of the advanced fusion reactor materials.
Si investigated by ac calorimetryTateiwa, Naoyuki; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo; Yasuda, Takashi*; Takeuchi, Tetsuya*; Settai, Rikio*; Onuki, Yoshichika
Journal of the Physical Society of Japan, 74(7), p.1903 - 1906, 2005/07
Times Cited Count：71 Percentile：89.02(Physics, Multidisciplinary)The pressure dependences of the antiferromagnetic and superconducting transition temperatures have been investigated by ac heat capacity measurement under high pressures for the heavy-fermion superconductor CePt
Si without inversion symmetry in the tetragonal structure. The N
el temperature 
= 2.2 K decreases with increasing pressure and becomes zero at the critical pressure 
0.6 GPa. On the other hand, the superconducting phase exists in a wider pressure region from ambient pressure to about 1.5 GPa. The pressure phase diagram of CePtSi is thus very unique and has never been reported before for other heavy fermion superconductors.
Miyawaki, Nobumasa; Kurashima, Satoshi; Okumura, Susumu; Chiba, Atsuya; Agematsu, Takashi; Kamiya, Tomihiro; Kaneko, Hirohisa; Nara, Takayuki; Saito, Yuichi; Ishii, Yasuyuki; et al.
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004), p.208 - 210, 2005/00
A project to expand at TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities of JAERI has been proposed to broaden applications in biotechnology and materials science. Heavy ions with energy more than 100 MeV/n are required for remarkable progress in breeding of plant and development of new materials. The magnet of a superconducting AVF cyclotron with a K number of 900 has been designed to cope with acceleration of both 150 MeV/n heavy ions and 300 MeV protons. The lower limit of energies has been investigated to overlap the energy region covered by the JAERI AVF cyclotron, required to increase beam time for present users. We have designed a beam transport system to satisfy requirements of the applications.
Fukuda, Mitsuhiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Ishii, Yasuyuki; Saito, Yuichi; Mizuhashi, Kiyoshi; Agematsu, Takashi; Chiba, Atsuya; Sakai, Takuro; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.643 - 645, 2004/08
A superconducting AVF cyclotron with a bending limit of 900 MeV and a focusing limit of 300 MeV is being designed to meet the requirements for the research in materials science and biotechnology at TIARA facility of JAERI. The spiral-sector shape of the cyclotron magnet has been optimized for acceleration of a 300 MeV proton to produce sufficient focusing forces in an extraction region. An energy range of the superconducting AVF cyclotron overlaps with that of the present K110 JAERI AVF cyclotron. Characteristics of a resonator for the superconducting AVF cyclotron have been investigated using the MAFIA code. An acceleration voltage in a frequency range of 24 to 64 MHz can be produced by the resonator with a 
/2 excitation mode.
Sn heat treatmentNakajima, Hideo; Hamada, Kazuya; Takano, Katsutoshi*; Okuno, Kiyoshi; Fujitsuna, Nobuyuki*
IEEE Transactions on Applied Superconductivity, 14(2), p.1145 - 1148, 2004/06
Times Cited Count：33 Percentile：77.62(Engineering, Electrical & Electronic)In ITER, the conductor for the Central Solenoid (CS) uses Incoloy 908, which requires special environment control to prevent cracks caused by Stress Accelerated Grain Boundary Oxidation (SAGBO) during Nb3Sn heat treatment. Use of a stainless steel jacket can simplify the design and fabrication because the special caution is not required for SAGBO. JAERI has already developed high manganese, JK2, whose thermal contraction from 300K to 4 K is almost the same as that of Incoloy: thus no change in the mechanical design of the CS is necessary. However, during the heat treatment, phosphorus enhances embrittlement of JK2. Carbon reduction and boron addition was considered to be a possible solution to mitigate the phosphorus effect. Jackets of low carbon and boron added JK2(JK2LB) were produced and tensile properties, fracture toughness, and crack propagation rate were measured at 4K. Elongation and fracture toughness at 4K after the heat treatment are 33% and 91 MPam
for the final jacket, which satisfy the ITER targets. JK2LB can be applied to the ITER CS.
Guillemet, L.*; Jager, B.*; Haange, R.*; Hamada, Kazuya; Hara, Eiji*; Kalinin, G.*; Kato, Takashi; Millet, F.*; Shatil, N.*
Proceedings of 19th International Cryogenic Engineering Conference (ICEC-19), p.105 - 108, 2002/07
Japan Atomic Energy Research Institute has designed a ITER cryoplant and cryo-distribution in the international collaboration. The ITER cryoplant that will be the largest cryogenic system for the Fusion facility in the world, is designed to be stable in operation despite the pulsed nature of heat deposition in the magnet system. The refrigeration capacity of cryoplant is 48 kW at 4.5 K of refrigeration power and 0.16 kg/s of supercritical helium supply. In the cryoplant, a supercritical helium pump and a cold compressor is applied, based on the successful achievement of cryogenic system for the ITER central solenoid model coil.
Hamada, Kazuya; Koizumi, Norikiyo
Purazuma, Kaku Yugo Gakkai-Shi, 78(7), p.616 - 624, 2002/07
In the Tokamak type fusion reactor design, a forced flow superconducting coil is applied from the viewpoint to high magnetic field, high withstand voltage performance and large electromagnetic force. In the forced flow magnets, it is well known that various electromagnetic phenomena are occurred by zero resistance and diamagnetic effect of superconductor and complicated structure of cable in conduit conductor (CICC). In the R&D of CICC, the study of hysteresis losses and coupling losses CICC have a lot of progress. For example, using the optimization of filament arrangement in superconducting strand and control of contact resistance of strand, ITER model coil project have a large achievement.
Hamada, Kazuya; Nakajima, Hideo; Okuno, Kiyoshi; Endo, Sakaru*; Kikuchi, Kenichi*; Kubo, Yoshio*; Aoki, Nobuo*; Yamada, Yuichi*; Osaki, Osamu*; Sasaki, Takashi*; et al.
JAERI-Tech 2002-027, 23 Pages, 2002/03
JAERI-Tech-2002-027.pdf:2.94MB
The Engineering Design Activities (EDA) for the International Thermonuclear Experimental Reactor (ITER) was performed under the collaboration of Japan, EU, Russia and the US. The EDA was successfully completed in July 2001, in which the development of fabrication technology for advanced components, such as superconducting coils, was conducted. The ITER magnet system consists of Toroidal Field coils, a Central Solenoid (CS), Poloidal Field coils and Correction coils. The construction of these coils requires advanced technologies that fairly exceeded those available at the start of the EDA. Therefore, CS Model Coil and TF Model Coil projects were implemented. To fabricate the CS Model Coil, the fabrication technologies for high performance strand, large cable, winding, heat treatment, joint and insulation are indispensable. This report describes the above detailed fabrication technologies successfully developed in the CS Model Coil Project.
Nakajima, Hideo; Hamada, Kazuya; Okuno, Kiyoshi; Hada, Kazuhiko; Tada, Eisuke
Proceedings of 10th International Conference on Nuclear Engineering (ICONE 10) (CD-ROM), 8 Pages, 2002/00
The Japan Atomic Energy Research Institute (JAERI) has conducted to develop a new design code for construction and operation/maintenance of the International Thermonuclear Experimental Reactor (ITER), which will be formed as a code case of ASME B&PV Code Section III, division 4, in collaboration with the ASME international. The new design code will also include the several new techniques and materials developed for each components of ITER. This paper describes the new cryogenic steels used in the magnet system and the design approach with taking account of unique features of the ITER superconducting magnets.
Tamai, Hiroshi; Ishida, Shinichi; Kurita, Genichi; Sakamoto, Yoshiteru; Fujita, Takaaki; Shirai, Hiroshi; Tsuchiya, Katsuhiko; Matsukawa, Makoto; Sakasai, Akira; Sakurai, Shinji; et al.
Proceedings of 29th European Physical Society Conference on Plasma Physics and Controlled Fusion, 4 Pages, 2002/00
This paper presents the feasibility and issues of steady state operation with a central current hole for JT-60SC, the superconducting tokamak to be modified from JT-60, from the view of reactor applicability of the current hole. An impact of the current hole on fusion engineering would stand in no necessity of central current drive leading to a remarkable reduction of neutral beam injection energy. The 1.5D time-dependent transport code analysis is made with using thermal and particle transport coefficients deduced from observations in JT-60U as a function of the magnetic shear. A steady state operation with HHy2~1.6 and beta_N~4 is obtained at Ip=1.5 MA, Bt=2 T and q95=4.5 by off-axis beams of 11.2 MW. The bootstrap fraction of ~75% of the plasma current and the current hole region of ~30% of the minor radius are sustained up to 70 s. The results suggest that a bootstrap current evolution near the current hole region and a relation between the location of ITB and the central current hole region are important to achieve a steady state plasma compatible with the current hole.
Kato, Takashi; Nakajima, Hideo; Isono, Takaaki; Hamada, Kazuya; Kawano, Katsumi; Sugimoto, Makoto; Nunoya, Yoshihiko; Koizumi, Norikiyo; Matsui, Kunihiro; Oshikiri, Masayuki*; et al.
Teion Kogaku, 36(6), p.315 - 323, 2001/06
no abstracts in English
Seki, Yasushi; Mori, Seiji*; Nishio, Satoshi; Ueda, Shuzo; Kurihara, Ryoichi
Journal of Nuclear Science and Technology, 37(Suppl.1), p.268 - 275, 2000/03
no abstracts in English
Watanabe, Kazuhiro; Akiba, Masato; Hatano, Toshihisa; Imai, Tsuyoshi; Kuriyama, Masaaki; Ohara, Yoshihiro; Okumura, Yoshikazu; Tsuji, Hiroshi
Proceedings of 10th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion (ITC-10), p.525 - 529, 2000/00
no abstracts in English
Konno, Chikara; Maekawa, Fujio; Oyama, Yukio; Wada, Masayuki*; Ikeda, Yujiro; Maekawa, Hiroshi; Kasugai, Yoshimi; M.Z.Youssef*; A.Kumar*; M.A.Abdou*
Fusion Engineering and Design, 42, p.267 - 273, 1998/00
Times Cited Count：2 Percentile：24.49(Nuclear Science & Technology)no abstracts in English
Wachi, Y.*; Hanai, S.*; *; *; *; Hamajima, Takataro*; *; Nakajima, Hideo; Tsuji, Hiroshi; Shinoda, K.*; et al.
Teion Kogaku, 33(7), p.479 - 484, 1998/00
no abstracts in English
Kato, Takashi; *; ; Matsui, Kunihiro; *; Tsuji, Hiroshi; N.Michel*; Yoshida, Kiyoshi; Shimamoto, Susumi
Fusion Technology, 30(3), p.1253 - 1257, 1996/12
no abstracts in English
