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Suzuki, Mitsutoshi; Iwabuchi, Junichi*; Kasai, Yoshimitsu*; Kuno, Yusuke; Mochiji, Toshiro
JAEA-Review 2012-044, 109 Pages, 2013/01
JAEA-Review-2012-044.pdf:6.71MB
JAEA has worked for the contribution to the world disarmament and nonproliferation through the United States and Russia cooperation on the excess weapon plutonium disposition from Russian as well as to acquire the basic data of the post irradiation test with the BN-600 and the vibropack MOX fuel fabrication technologies. To support the initiative of Japan government, JAEA has started the joint research activities with some of the Russian national laboratories under the MINATOM in 1999. Since then, JAEA has been involved into the demonstration experiment for the vibropack fuel irradiation with the BN-600 that was managed by the PESCO corp. under the contract with MEXT. The joint researches with Russian national laboratories and the demonstration studies on vibropac MOX fuel assemblies from 1999 to 2011 are surmmarized in this document.
Mayorshin, A. A.*; Skiba, O. V.*; Bychkov, A. V.*; Kisly, V. A.*; Shishalov, O. V.*; Krukov, F. N.*; Novoselov, A. E.*; Markov, D. V.*; Green, P. I.*; Funada, Toshio; et al.
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 11 Pages, 2012/00
The paper presents progress results, including fabrication of vibropac MOX fuel pins and 21 FAs for fast reactor BN-600, irradiation parameters and PIE results. It is shown, that no violations of safe operation limits take place. The activities within the framework of the Demonstration experiment is based on the international cooperation and have been performed with the support and participation Russian and Japanese organizations RIAR, IPPE, OKBM, BNPP, MEXT, JAEA, PESCO. The goal of the experiment is to validate possibility of using vibropac MOX FA for weapon plutonium disposition.
Ogawa, Hiroaki; Sugie, Tatsuo; Kasai, Satoshi*; Katsunuma, Atsushi*; Hara, Hirotsugu*; Takeyama, Norihide*; Kusama, Yoshinori
Fusion Engineering and Design, 83(10-12), p.1405 - 1409, 2008/12
Times Cited Count：15 Percentile：66.71(Nuclear Science & Technology)no abstracts in English
Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Kasai, Satoshi*; Kusama, Yoshinori
Proceedings of 18th International Toki Conference on Development of Physics and Technology of Stellarator/Heliotrons en route to Demo (ITC-18) (CD-ROM), p.450 - 453, 2008/12
Sugie, Tatsuo; Ogawa, Hiroaki; Kasai, Satoshi*; Kusama, Yoshinori
AIP Conference Proceedings 988, p.218 - 221, 2008/04
The detailed design of the Impurity Influx Monitor (divertor) has been carried out to provide the measurement capability in the harsh environment. The potential damaging effects for the first mirrors mounted close to the plasma are the formations of coatings of impurities and the deposition of the dust. Mitigating measures to minimize the degradation of their performance by these effects, such as changes in the reflectivity, are adopted: for example, the plasma is viewed through a small aperture, and baffle plates are inserted in front of the first mirrors. However, it will not be possible to prevent the degradation completely. It is important to know the change of the sensitivity of the optical systems. It is not feasible to install a light source in the vacuum chamber of ITER during operations and so an alternative method is needed. The in-situ calibration system using a micro retro-reflector array has been developed as a possible method.
Ogawa, Hiroaki; Sugie, Tatsuo; Kasai, Satoshi; Katsunuma, Atsushi*; Hara, Hirotsugu*; Kusama, Yoshinori
Plasma and Fusion Research (Internet), 2, p.S1054_1 - S1054_4, 2007/11
no abstracts in English
Hoshino, Katsumichi; Ido, Takeshi*; Nagashima, Yoshihiko*; Shinohara, Koji; Ogawa, Hiroaki; Kamiya, Kensaku; Kawashima, Hisato; Tsuzuki, Kazuhiro*; Kusama, Yoshinori; Oasa, Kazumi; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
We report on the potential/density fluctuations in the JFT-2M tokamak. We identified a geodesic acoustic mode (GAM) and its electric field structure. The GAM interacts with the background turbulence in consistent with a drift wave - zonal flow theory. The GAM modulates the turbulence, and the suppression depends on the direction and gradient of the flow velocity in consistent with a theory. During the H-mode, the GAM disappears presumably due to the suppression of the turbulence. We analysed the low frequency potential oscillation during the H-mode. A wavelet analysis showed a low frequency characteristic potential fluctuations (several handred kHz), which disappears in the L-mode and at the occurence of ELM. Observed poloidal flow is about 20 times as large as that of the GAM during the H-mode. If the potential has a spatial inhomogineity, there is a possibility that this low frequency fluctuation comes from the EXB flow or the zonal flow.
Tsuzuki, Kazuhiro; Kamiya, Kensaku; Shinohara, Koji; Bakhtiari, M.*; Ogawa, Hiroaki; Kurita, Genichi; Takechi, Manabu; Kasai, Satoshi; Sato, Masayasu; Kawashima, Hisato; et al.
Nuclear Fusion, 46(11), p.966 - 971, 2006/11
Times Cited Count：16 Percentile：48.35(Physics, Fluids & Plasmas)no abstracts in English
Ogawa, Hiroaki; Sugie, Tatsuo; Katsunuma, Atsushi*; Kasai, Satoshi
JAEA-Technology 2006-015, 119 Pages, 2006/03
JAEA-Technology-2006-015.pdf:7.26MB
no abstracts in English
Kasai, Satoshi*; Kamiya, Kensaku; Shinohara, Koji; Kawashima, Hisato; Ogawa, Hiroaki; Uehara, Kazuya; Miura, Yukitoshi; Okano, Fuminori; Suzuki, Sadaaki; Hoshino, Katsumichi; et al.
Fusion Science and Technology, 49(2), p.225 - 240, 2006/02
Times Cited Count：3 Percentile：24.11(Nuclear Science & Technology)The diagnostic system of JFT-2M has consisted of about 30 individual diagnostic instruments,which were used to study the plasma production, control, equilibrium, stability, confinement, plasma heating by NBI and/or RF (LH, ICRF, ECH) and current drive by RF. In these instruments, the motional Stark effect (MSE) polarimeter, charge exchanged recombination spectroscopy (CXRS), heavy-ion beam probe (HIBP), time of flight (TOF) neutral particle analyzer, etc. have contributed to make clear the improved mechanism of confinement such as H-mode and High Recycling Steady (HRS) H-mode, and to search the operational region of these modes.The infrared TV camera system and lost ion probe have played a very important role to investigate the heat load onto the walls due to ripple loss particles and escaping ions from core plasma, respectively.
Ogawa, Hiroaki; Ogawa, Toshihide; Tsuzuki, Kazuhiro; Kawashima, Hisato; Kasai, Satoshi*; Kashiwa, Yoshitoshi; Hasegawa, Koichi; Suzuki, Sadaaki; Shibata, Takatoshi; Miura, Yukitoshi; et al.
Fusion Science and Technology, 49(2), p.209 - 224, 2006/02
Times Cited Count：3 Percentile：24.11(Nuclear Science & Technology)no abstracts in English
Tsuzuki, Kazuhiro*; Kimura, Haruyuki; Kusama, Yoshinori; Sato, Masayasu; Kawashima, Hisato; Kamiya, Kensaku; Shinohara, Koji; Ogawa, Hiroaki; Uehara, Kazuya; Kurita, Genichi; et al.
Fusion Science and Technology, 49(2), p.197 - 208, 2006/02
Times Cited Count：11 Percentile：60.27(Nuclear Science & Technology)no abstracts in English
Miura, Yukitoshi; Mori, Masahiro; Shoji, Teruaki; Matsumoto, Hiroshi; Kamiya, Kensaku; Ida, Katsumi*; Kasai, Satoshi*
Fusion Science and Technology, 49(2), p.96 - 121, 2006/02
Times Cited Count：4 Percentile：13.73(Nuclear Science & Technology)The improved modes observed in JFT-2M are characterized by the two improvements, i.e. one is the H-mode at the edge, and other modes are core improvement with peaked profiles near the center. The improvement of the pellet injected H-mode was a combination of H-mode and the core improvement. The discovery of limiter H-mode had an impact on the physics understanding of the H-mode and showed the formation of transport barrier at a place without discontinuity of the magnetic field line topology. The appearance of ELMs by applying ergodic fields was investigated and it was clarified that n
4 helical components were effective to produce ELMs. A SOL biasing had effects to compress neutrals at divertor region. It would be understood that the compressed neutrals at divertor region might make a situation of low L/H threshold power. High recycling steady (HRS) H-mode could be reproducibly obtained by boronization. It was found that HRS appears at the pedestal collisionality greater than 1.
Kamiya, Kensaku; Kawashima, Hisato; Ido, Takeshi*; Oyama, Naoyuki; Bakhtiari, M.*; Kasai, Satoshi; Kusama, Yoshinori; Miura, Yukitoshi; Ogawa, Hiroaki; Tsuzuki, Kazuhiro; et al.
Nuclear Fusion, 46(2), p.272 - 276, 2006/02
Times Cited Count：3 Percentile：10.78(Physics, Fluids & Plasmas)An attractive operational regime without any large ELMs, namely High Recycling Steady (HRS) H-mode, was found on JFT-2M during Y2000 campaign after boronization. Recent experiments have concentrated on the studies of the access conditions for the HRS regime, in terms of the pedestal parameters. The HRS regime was more likely at higher edge density and lower edge temperature, which corresponds to the normalized electron collisionality of 1 in the plasma edge region.
Sugie, Tatsuo; Kasai, Satoshi; Taniguchi, Masaki; Nagatsu, Masaaki*; Nishitani, Takeo
Journal of Nuclear Materials, 329-333(2), p.1481 - 1485, 2004/08
Times Cited Count：30 Percentile：85.95(Materials Science, Multidisciplinary)In ITER, the effect of lower energy particle bombardment is important for mirrors located near the divertor where the low temperature plasma is formed. The test pieces of molybdenum mirrors and a tungsten mirror were irradiated by high flux and low energy (67-80 eV) deuterium ions using SLEIS (Super Low Energy Ion Source with High Ion Flux) facility at the temperature of around 100 
C. The molybdenum mirror manufactured by sintering and melting the thin layer of the surface by electron beam in order to eliminate holes on the surface has a higher reflectivity before irradiation than the mirrors without melting the surface, but the reflectivity decreases rapidly with the irradiation fluence due to the generation of blisters on the mirror surface. The reflectivity of molybdenum mirror manufactured by sintering only did not decrease so significantly (less than 10 % at the fluence of 1.3 
10
m
). The molybdenum and tungsten mirrors manufactured by sintering without melting the surface have a potential for plasma facing mirrors in ITER.
Ogawa, Hiroaki; Yamauchi, Yuji*; Tsuzuki, Kazuhiro; Kawashima, Hisato; Sato, Masayasu; Shinohara, Koji; Kamiya, Kensaku; Kasai, Satoshi; Kusama, Yoshinori; Yamaguchi, Kaoru*; et al.
Journal of Nuclear Materials, 329-333(Part1), p.678 - 682, 2004/08
Times Cited Count：4 Percentile：29.26(Materials Science, Multidisciplinary)no abstracts in English
Tsuzuki, Kazuhiro; Shinohara, Koji; Kamiya, Kensaku; Kawashima, Hisato; Sato, Masayasu; Kurita, Genichi; Bakhtiari, M.; Ogawa, Hiroaki; Hoshino, Katsumichi; Kasai, Satoshi; et al.
Journal of Nuclear Materials, 329-333(1), p.721 - 725, 2004/08
Times Cited Count：7 Percentile：45.11(Materials Science, Multidisciplinary)no abstracts in English
Kamiya, Kensaku; Bakhtiari, M.; Kasai, Satoshi; Kawashima, Hisato; Kusama, Yoshinori; Miura, Yukitoshi; Ogawa, Hiroaki; Oyama, Naoyuki; Sato, Masayasu; Shinohara, Koji; et al.
Plasma Physics and Controlled Fusion, 46(5A), p.A157 - A163, 2004/05
Times Cited Count：21 Percentile：56.48(Physics, Fluids & Plasmas)A new operating regime, High Recycling Steady (HRS) H-mode regime, has been discovered on JFT-2M, which is easily reproduced under the wall fueling from the boronized first wall. Accompanying the HRS H-mode transition, the coherent magnetic and floating potential fluctuations are seen on magnetic probes at vessel wall and Langmuir probe in SOL, respectively. These coherent fluctuations have a frequency of the order of 10-100 kHz with significant variation, which is recognized to be important to enhance the particle transport. The HRS can be seen even at 
3 with 
/
0.4 for the fixed delta
0.4 in the standard single-null divertor configuration. Recent experimental results from JFT-2M show that the plasma shape also seems to play an important role in determining the type of ELMs. The HRS regime can be extended up to delta0.75 and 2.6 in the double-null configuration, while lower delta boundary exists at delta0.3 with moderate 4 even at high recycling and/or density condition of /0.4.
Arai, Takashi; Nishiyama, Tomokazu; Yagyu, Junichi; Kasai, Satoshi; Sone, Isamu*; Abe, Mitsushi*; Miya, Naoyuki
Fusion Science and Technology, 45(1), p.65 - 68, 2004/01
Times Cited Count：2 Percentile：17.18(Nuclear Science & Technology)In a nuclear fusion experiment device, a plasma discharge is to be sustained for a long time in steady state operation. In such a device an electromagnetic sensor that has a signal integrator to measure direct currents will cause a technical problem of zero point drift on signals. So, the detection device using new technology for direct current measurement, optical current transformer (optical CT), was developed. The device has an optical fiber specified for 1550nm (wavelength) was manufactured, and was applied to JT-60U experiments. A gamma ray irradiation examination was also done to the optical CT
Hoshino, Katsumichi; Nagashima, Yoshihiko*; Ido, Takeshi*; Tsuzuki, Kazuhiro; Kawashima, Hisato; Ogawa, Hiroaki; Bakhtiari, M.; Shinohara, Koji; Uehara, Kazuya; Oasa, Kazumi; et al.
Journal of Plasma and Fusion Research SERIES, Vol.6, p.345 - 348, 2004/00
no abstracts in English
