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Abe, Yuta; Nagai, Keiichi; Maie, Mitsuyoshi*; Nakano, Natsuko*; Kawashima, Yuichi*; Takesue, Naohisa*; Saito, Junichi
Dai-23-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (USB Flash Drive), 5 Pages, 2018/06
no abstracts in English
Shibanuma, Kiyoshi; Arai, Takashi; Hasegawa, Koichi; Hoshi, Ryo; Kamiya, Koji; Kawashima, Hisato; Kubo, Hirotaka; Masaki, Kei; Saeki, Hisashi; Sakurai, Shinji; et al.
Fusion Engineering and Design, 88(6-8), p.705 - 710, 2013/10
Times Cited Count：10 Percentile：61.16(Nuclear Science & Technology)Yanagisawa, Kazuaki; Ito, Keishiro*; Katsuki, Chisato*; Kawashima, Kei*; Shirabe, Masashi*
Scientometrics, 84(3), p.563 - 573, 2010/09
Times Cited Count：5 Percentile：46.04(Computer Science, Interdisciplinary Applications)no abstracts in English
Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.
JAEA-Research 2010-019, 194 Pages, 2010/08
JAEA-Research-2010-019-01.pdf:48.47MBJAEA-Research-2010-019-02.pdf:19.4MB
This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m
. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.
Shibanuma, Kiyoshi; Arai, Takashi; Kawashima, Hisato; Hoshino, Katsumichi; Hoshi, Ryo; Kobayashi, Kaoru; Sawai, Hiroaki; Masaki, Kei; Sakurai, Shinji; Shibama, Yusuke; et al.
Journal of Plasma and Fusion Research SERIES, Vol.9, p.276 - 281, 2010/08
The JT-60 SA project is a combined project of JA-EU satellite tokamak program under the Broader Approach (BA) agreement and JA domestic program. Major components of JT-60SA for assembly are vacuum vessel (VV), superconducting coils (TF coils, EF coils and CS coil), in-vessel components such as divertor, thermal shield and cryostat. An assembly frame (with the dedicated cranes), which is located around the tokamak, is adopted to carry out effectively the assembly of tokamak components in the tokamak hall, independently of the facility cranes in the building. The assembly frame also provides assembly tools and jigs with jacks to support temporarily the components as well as to adjust the components at right positions. In this paper, the assembly scenario and scequence of the major components such as VV and TFC and the concept of the assembly frame including special jigs and fixtures are discussed.
Yanagisawa, Kazuaki; Kawashima, Kei*; Katsuki, Chisato*; Ito, Keishiro*
JAEA-Review 2009-050, 13 Pages, 2010/02
JAEA-Review-2009-050.pdf:6.63MB
Bibliometric study by means of research papers revealed the followings; (1) Nuclear Safety Research (NSR) performed in Japan is the 2nd highest in the world followed by USA. The share of JAERI for safety paper publication is about 25% in Japan (2) During past 25 years, JAERI is predominant at 39 safety fields out of 97, that is, 40% to the total. This is the fact revealed from comparison of published number of research papers with those of other organizations. (3) JAERI is recently changing its stress point from reactor-oriented accidents to the down stream of nuclear fuel cycling. There existed impact of TMI-2 accident on NSR-JAERI, especially in the field of thermal hydraulics, LOCA, severe accident and risk analysis.
Yanagisawa, Kazuaki; Ito, Keishiro*; Katsuki, Chisato*; Kawashima, Kei*; Shirabe, Masashi*
JAEA-Review 2009-022, 26 Pages, 2009/09
JAEA-Review-2009-022.pdf:17.62MB
An outcome of nuclear safety research done by JAERI was case studied by the bibliometric method. (1) For LOCA (loss-of-coolant accident) a domestic share of JAERI in monoclinic research paper was 63% at the past (20) 1978-1982 but was decreased to 40% at the present 1998-2002. For co-authored papers a domestic share between JAERI and PS (public sectors) is almost zero at past (20) but increased to 4% at the present. Research cooperation is active between Tokyo University and JAERI or between JAERI and Nagoya University. (2) Project-type research is to have a large monopolization in papers and that of basic-type research is to have a large DRN. (3)For reprocessing, PS had a monopolistic position with a domestic share of 71% and a share of JAERI was about 20%. (4) LOCA and RIA outputs born by NSR-JAERI coincided partly to those of the Safety Licensing Guidelines but a share of contribution done by JAERI was difficult to obtain due to the lack of necessary information.
Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Kawashima, Hisato; Shimizu, Katsuhiro; Asakura, Nobuyuki
Plasma and Fusion Research (Internet), 4, p.025_1 - 025_7, 2009/08
The volume recombination in detached divertor plasmas is a key process to reduce the ion flux to the divertor plates. Two-dimensional measurement is one of the ways to investigate a spatial structure of the volume recombination. In this work, the deuterium Balmer-series lines from a detached divertor plasma were observed two-dimensionally with a spatial resolution of 1 cm and were reconstructed into two-dimensional emissivities with a tomography technique. The ratio of the D
to the D
emissivity was compared to that calculated by the collisional-radiative model. This ratio could not be explained only by the excitation of D by electron impact, indicating that the volume recombination contributed to the D emission. This is the case for the region above the inner strike point with 8 cm and 4 cm, respectively, in the r- and the z-direction on the poloidal cross-section.
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Kawashima, Hisato; Kurita, Genichi; Tanigawa, Hiroyasu; Nakamura, Hirofumi; Honda, Mitsuru; Saito, Ai*; Sato, Satoshi; et al.
Nuclear Fusion, 49(7), p.075029_1 - 075029_10, 2009/07
Times Cited Count：137 Percentile：97.72(Physics, Fluids & Plasmas)Recent design study on SlimCS focused mainly on the torus configuration including blanket, divertor, materials and maintenance scheme. For vertical stability of elongated plasma and high beta access, a sector-wide conducting shell is arranged in between replaceable and permanent blanket. The reactor adopts pressurized-water-cooled solid breeding blanket. Compared with the previous advanced concept with supercritical water, the design options satisfying tritium self-sufficiency are relatively scarce. Considered divertor technology and materials, an allowable heat load to the divertor plate should be 8 MW/m or lower, which can be a critical constraint for determining a handling power of DEMO (a combination of alpha heating power and external input power for current drive).
Sakurai, Shinji; Kawashima, Hisato; Higashijima, Satoru; Shimizu, Katsuhiro; Masaki, Kei; Asakura, Nobuyuki; Shibama, Yusuke; Sakasai, Akira
Journal of Nuclear Materials, 390-391, p.891 - 894, 2009/06
Times Cited Count：1 Percentile：10.22(Materials Science, Multidisciplinary)The entire plasma facing components should be water-cooled in JT-60SA. A cassette module of divertor is introduced for remote maintenance. The divertor targets are mounted on the cassette. A brazed carbon fiber composite target is promising candidate for the divertor target. The latest results of mock-ups test clarified that thermal fatigue life cycles are more than 1000 cycles of 15 MW/m
10 sec. The divertor is designed to control divertor detachment for heat load reduction. The vertical targets and a "V-shaped corner" like as that in ITER are adopted to enhance detachment. Divertor heat load and pumping efficiency has been evaluated, using 2D plasma fluid (SOLDOR) and neutral Monte-Carlo (NEUT2D) code. The plasma detachment occurs near the outer-strike point within the "V-shaped corner", which results in low peak heat flux density 5.8 MW/m for the case with additional gas puff of 510
/s compared to 11.4 MW/m for the case without "V-shaped corner".
Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Shimizu, Katsuhiro; Kawashima, Hisato; Asakura, Nobuyuki
Plasma and Fusion Research (Internet), 2, p.S1121_1 - S1121_4, 2007/11
Understanding deuterium particle behavior in the divertor plasma is necessary to study the ionizing and recombining plasmas. Two-dimensional spectroscopic measurement of deuterium emission is useful to understand deuterium particle behavior in divertor plasmas. The information of the ionization and recombination can be obtained by measurement of deuterium Balmer-series lines. A wide-spectral-band spectrometer with a CCD detector was used to observe deuterium Balmer-series lines with two-dimensional spatial distribution in the JT-60U divertor region. From the measurement, we can obtain a two-dimensional distribution of D and D
using a computer tomography technique. The D emission was strong above the strike point in the inner divertor and around the strike point in the outer divertor. The D emission was strong above the strike point in the inner divertor.
Tobita, Kenji; Nishio, Satoshi; Sato, Masayasu; Sakurai, Shinji; Hayashi, Takao; Shibama, Yusuke; Isono, Takaaki; Enoeda, Mikio; Nakamura, Hirofumi; Sato, Satoshi; et al.
Nuclear Fusion, 47(8), p.892 - 899, 2007/08
Times Cited Count：57 Percentile：86.6(Physics, Fluids & Plasmas)The concept for a compact DEMO reactor named "SlimCS" is presented. Distinctive features of the concept is low aspect ratio (
= 2.6) and use of a reduced-size center solenoid (CS) which has a function of plasma shaping rather than poloidal flux supply. The reduced-size CS enables us to introduce a thin toroidal field (TF) coil system which contributes to reducing the weight and construction cost of the reactor. SlimCS is as compact as advanced commercial reactor designs such as ARIES-RS and produces 1 GWe in spite of moderate requirements for plasma parameters. Merits of low-, i.e. vertical stability for high elongation and high beta limit are responsible for such reasonable physics requirements.
Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.
Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12
To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.
Watanabe, Kazuhiro; Kashiwagi, Mieko; Kawashima, Shuichi*; Ono, Yoichi*; Yamashita, Yasuo*; Yamazaki, Choji*; Hanada, Masaya; Inoue, Takashi; Taniguchi, Masaki; Okumura, Yoshikazu; et al.
Nuclear Fusion, 46(6), p.S332 - S339, 2006/06
Times Cited Count：33 Percentile：72.61(Physics, Fluids & Plasmas)no abstracts in English
Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.
Nuclear Fusion, 46(3), p.S29 - S38, 2006/03
Times Cited Count：13 Percentile：41.76(Physics, Fluids & Plasmas)The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.
Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.
Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02
Times Cited Count：1 Percentile：9.98(Nuclear Science & Technology)no abstracts in English
plasma operationTamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.
Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12
Times Cited Count：15 Percentile：45.53(Physics, Fluids & Plasmas)Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.
Miura, Yukitoshi; *; *; Hoshino, Katsumichi; *; *; Kasai, Satoshi; Kawakami, Tomohide; Kawashima, Hisato; Maeda, M.*; et al.
Fusion Energy 1996, p.167 - 175, 1997/05
no abstracts in English
*; *; *; *; *; *; *; Oikawa, Toshihiro; *; *; et al.
Fusion Energy 1996, p.885 - 890, 1997/05
no abstracts in English
Tamai, Hiroshi; Shoji, Teruaki; Miura, Yukitoshi; Nagashima, Keisuke; Kawashima, Hisato; Matsuda, Toshiaki; Ogawa, Hiroaki; Maeno, Masaki; Yamauchi, Toshihiko; Uehara, Kazuya; et al.
IAEA-CN-60/A1-7, 0, p.137 - 144, 1995/00
no abstracts in English
