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Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：7 Percentile：40.14(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
/GaN stacks for high-quality GaN-based metal-oxide-semiconductor devices with improved gate dielectric reliabilityYamada, Takahiro*; Watanabe, Kenta*; Nozaki, Mikito*; Yamada, Hisashi*; Takahashi, Tokio*; Shimizu, Mitsuaki*; Yoshigoe, Akitaka; Hosoi, Takuji*; Shimura, Takayoshi*; Watanabe, Heiji*
Applied Physics Express, 11(1), p.015701_1 - 015701_4, 2018/01
Times Cited Count：47 Percentile：85.39(Physics, Applied)A simple and feasible method for fabricating high-quality and highly reliable GaN-based metal-oxide-semiconductor (MOS) devices was developed on the basis of systematic physical and electrical characterizations. Chemical vapor deposition of SiO films directly onto GaN substrates forming Ga-oxide interlayers was used to fabricate SiO/GaO
/GaN stacked structures. Although well-behaved hysteresis-free GaN-MOS capacitors with extremely low interface state density below 10
cm
eV
were obtained by post-deposition annealing, Ga diffusion into overlying SiO layers severely degraded the insulating property and dielectric breakdown characteristics of the MOS devices. However, this problem was found to be solved by employing rapid thermal processing, leading to superior performance of the GaN-MOS devices in terms of interface quality, insulating property and gate dielectric reliability.
Watanabe, Kazuhito; Nakamura, Makoto; Tobita, Kenji; Someya, Yoji; Tanigawa, Hisashi; Uto, Hiroyasu; Sakamoto, Yoshiteru; Araki, Takao*; Asano, Shiro*; Asano, Kazuhito*
Proceedings of 26th IEEE Symposium on Fusion Engineering (SOFE 2015), 6 Pages, 2016/06
Safety studies of a water-cooled fusion DEMO reactor have been performed. In the event of the blanket cooling pipe break outside the vacuum vessel, i.e. ex-vacuum vessel loss of coolant accident (ex-VV LOCA), the pressurized steam and air may lead to damage reactor building walls which have confinement function, and to release the radioactive materials to the environment. In response to this accident, we proposed three cases of confinement strategies. In each case, the pressure and thermal loads to the confinement boundaries and total mass of tritium released to outside the boundaries were analyzed by accident analysis code MELCOR modified for fusion reactor. These analyses developed design parameters to maintain the integrity of the confinement boundaries.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
-raysArisaka, Makoto; Watanabe, Masayuki; Ishizaki, Manabu*; Kurihara, Masato*; Chen, R.*; Tanaka, Hisashi*
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1543 - 1547, 2015/02
Times Cited Count：15 Percentile：74.40(Chemistry, Analytical)The influence of irradiation with -rays to metal hexacyanoferrate (MHCF: M = Fe, Cu or Ni), which is known as an adsorbent for selective adsorption of cesium (Cs) ion in solution, on Cs adsorption ability and stability was investigated in HNO
solutions. Under the adsorbed dose conditions (50-300 kGy), it was found that the MHCF is fully stable although the radiolytic decomposition of MHCF was slightly observed with an increase of the total adsorbed dose, which was confirmed by an increment of Fe, Cu or Ni concentration in HNO solution after the irradiation. The weight percent of the metal in the solution to initial weight of MHCF was less than unity. Moreover, no change in composition of carbon, hydrogen and nitrogen in MHCF was observed. On the other hand, the distribution coefficients of Cs to the irradiated MHCF were independent of the total adsorbed dose. This indicates that the Cs adsorption ability was maintained under -ray irradiation.
Nakamura, Makoto; Tobita, Kenji; Gulden, W.*; Watanabe, Kazuhito*; Someya, Yoji; Tanigawa, Hisashi; Sakamoto, Yoshiteru; Araki, Takao*; Matsumiya, Hisato*; Ishii, Kyoko*; et al.
Fusion Engineering and Design, 89(9-10), p.2028 - 2032, 2014/10
Times Cited Count：15 Percentile：71.78(Nuclear Science & Technology)After the Fukushima Dai-ichi nuclear accident, a social need for assuring safety of fusion energy has grown gradually in the Japanese (JA) fusion research community. DEMO safety research has been launched as a part of BA DEMO Design Activities (BA-DDA). This paper reports progress in the fusion DEMO safety research conducted under BA-DDA. Safety requirements and evaluation guidelines have been, first of all, established based on those established in the Japanese ITER site invitation activities. The amounts of radioactive source terms and energies that can mobilize such source terms have been assessed for a reference DEMO, in which the blanket technology is based on the Japanese fusion technology R&D programme. Reference event sequences expected in DEMO have been analyzed based on the master logic diagram and functional FMEA techniques. Accident initiators of particular importance in DEMO have been selected based on the event sequence analysis.
Nakamura, Makoto; Tobita, Kenji; Someya, Yoji; Tanigawa, Hisashi; Gulden, W.*; Sakamoto, Yoshiteru; Araki, Takao*; Watanabe, Kazuhito*; Matsumiya, Hisato*; Ishii, Kyoko*; et al.
Plasma and Fusion Research (Internet), 9, p.1405139_1 - 1405139_11, 2014/10
Key aspects of the safety study of a water-cooled fusion DEMO reactor is reported. Safety requirements, dose target, DEMO plant model and confinement strategy of the safety study are briefly introduced. The internal hazard of a water-cooled DEMO, i.e. radioactive inventories, stored energies that can mobilize these inventories and accident initiators and scenarios, are evaluated. It is pointed out that the enthalpy in the first wall/blanket cooling loops, the decay heat and the energy potentially released by the Be-steam chemical reaction are of special concern for the water-cooled DEMO. An ex-vessel loss-of-coolant of the first wall/blanket cooling loop is also quantitatively analyzed. The integrity of the building against the ex-VV LOCA is discussed.
Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Watanabe, Kazuyoshi; Ida, Mizuho*; Ito, Yuzuru; Niitsuma, Shigeto; Edao, Yuki; et al.
Fusion Science and Technology, 66(1), p.46 - 56, 2014/07
Times Cited Count：4 Percentile：28.72(Nuclear Science & Technology)
adsorption 
lattice defect sites of Prussian blue filled with coordination and crystallization water moleculesIshizaki, Manabu*; Akiba, Sae*; Otani, Asako*; Hoshi, Yuji*; Ono, Kenta*; Matsuba, Mayu*; Togashi, Takanari*; Kanaizuka, Katsuhiko*; Sakamoto, Masatomi*; Takahashi, Akira*; et al.
Dalton Transactions, 42(45), p.16049 - 16055, 2013/12
Times Cited Count：194 Percentile：99.56(Chemistry, Inorganic & Nuclear)We have revealed the fundamental mechanism of specific Cs adsorption into Prussian blue (PB) in order to develop high-performance PB-based Cs adsorbents in the wake of the Fukushima nuclear accident. We compared two types of PB nanoparticles with formulae of Fe
[Fe
(CN)
]3
xHO (x = 10-15) (PB-1) and (NH)0.70Fe1.10[Fe(CN)]1.7HO (PB-2) with respect to the Cs adsorption ability. The synthesised PB-1, by a common stoichiometric aqueous reaction between 4Fe
and 3[Fe(CN)]
, showed much more efficient Cs adsorption ability than did the commercially available PB-2.
Imai, Hisashi*; Amemiya, Kiyoshi*; Matsui, Hiroya; Sato, Toshinori; Saegusa, Hiromitsu; Watanabe, Kunio*
Doboku Gakkai Rombunshu, C (Chiken Kogaku) (Internet), 69(3), p.285 - 296, 2013/07
The more accurate understanding and appropriate control of unsaturated area around tunnel excavated in deep rock-mass are required, for the geological isolation of radioactive waste project and also underground rock cavern storage project of liquefied petroleum gas. The numerical simulation of seepage flow is usually conducted to understand and evaluate the unsaturated zone around tunnel. The unsaturated parameters (such as moisture characteristic curve and relative permeability) and appropriate control of boundary condition are indispensable for the simulation. Authors developed methodology to measure unsaturated parameters utilizing the measuring method conventionally applied to soils and showed the efficiency of the method via a laboratory experiment. The idea of combining seepage face condition and flow rate fixed condition was derived, and the efficiency was shown in an model simulation. The two developments enabled the accurate estimation and understanding the evolution of unsaturated zone around tunnel.
Chen, R.*; Tanaka, Hisashi*; Kawamoto, Toru*; Asai, Miyuki*; Fukushima, Chikako*; Na, H.*; Kurihara, Masato*; Watanabe, Masayuki; Arisaka, Makoto; Nankawa, Takuya
Electrochimica Acta, 87, p.119 - 125, 2013/01
Times Cited Count：112 Percentile：94.50(Electrochemistry)A novel electrochemical adsorption system using a nanoparticle film of copper (II) hexacyanoferrate (III) was proposed for selectively removing cesium from wastewater. This system can be used for cesium separation without extra chemical reagents or any filtration treatment. Cesium uptake and elution can be simply controlled by switching the applied potentials between anodes and cathodes. Data from batch kinetic studies well fitted the intraparticle diffusion equation, reflecting a two-step process: a steepest ascent portion followed by a plateau extending to the equilibrium. The effective cesium removal with a high distribution coefficient (
5
10
mL/g) can be adopted in a large pH range from 0.3 to 9.2, and in the presence of several diverse coexisting alkaline cations, suggesting it can be taken as a promising technology for actual nuclear wastewater treatment.
Wakai, Eiichi; Kondo, Hiroo; Sugimoto, Masayoshi; Fukada, Satoshi*; Yagi, Juro*; Ida, Mizuho; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Watanabe, Kazuyoshi; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 88(12), p.691 - 705, 2012/12
no abstracts in English
Chen, R.*; Tanaka, Hisashi*; Kawamoto, Toru*; Asai, Miyuki*; Fukushima, Chikako*; Kurihara, Masato*; Watanabe, Masayuki; Arisaka, Makoto; Nankawa, Takuya
Electrochemistry Communications, 25, p.23 - 25, 2012/11
Times Cited Count：56 Percentile：80.70(Electrochemistry)We first synthesized water-dispersed nanoparticle copper hexacyanoferrate (CuHCF) ink and then coated its nanoparticles on electrodes to electrochemically remove cesium from wastewater. Cesium uptake and elution can be controlled by switching the potentials between anodes and cathodes. Effective cesium removal can be adopted in a large pH range from 0.2 to 8.9, and in the presence of several diverse coexisting alkaline cations, suggesting that it can be taken as a promising technology for actual radioactive wastewater treatment. The prepared CuHCF nanoparticles can be simply and uniformly coated on electrodes by wet process like conventional printing methods, so any sizes or patterns are feasible at low cost, which indicated the potential as a promising sorption electrode of large size in the columns for sequential removal and recycle of Cs from wastewater.
Ca
Cu
O
superconductorTokiwa, Kazuyasu*; Mikusu, Satoshi*; Higemoto, Wataru; Nishiyama, Kusuo*; Iyo, Akira*; Tanaka, Yasumoto*; Kotegawa, Hisashi*; Mukuda, Hidekazu*; Kitaoka, Yoshio*; Watanabe, Tsuneo*
Physica C, 460-462(2), p.892 - 895, 2007/09
Times Cited Count：3 Percentile：17.16(Physics, Applied)Zero- and longitudinal-field muon-spin rotation (ZF-
SR and LF-SR) measurements were carried out on a multi-layered HgBaCaCuO (Hg-1245) superconductor with 
of 108 K. With decreasing temperature, the observed ZF-SR function changed from a Gaussian-type to an exponential-type below 60 K and zero field muon precession was also observed below 45 K. These SR signals are attributed to the development of the antiferromagnetic ordering in inner CuOplanes with a low carrier concentration. These results seem to indicate clear evidence that antiferromagnetism microscopically coexists with superconductivity in the Hg-1245 superconductor below 60 K.
Kubono, Shigeru*; Teranishi, Takashi*; Notani, Masahiro*; Yamaguchi, Hidetoshi*; Saito, Akito*; He, J. J.*; Wakabayashi, Yasuo*; Fujikawa, Hisashi*; Amadio, G.*; Baba, Hidetada*; et al.
Nuclear Physics A, 758, p.733 - 736, 2005/07
Times Cited Count：1 Percentile：14.20(Physics, Nuclear)With using 
RNB from CRIB, proton inelastic scattering was observed. From this experiment, some resonance parameters have been deduced for the key reaction, 
at the explosive hydrogen burning stage in stars. Proton inelastic scattering of 
are also reported.
Nishitani, Tomohiro; Nakanishi, Tsutomu*; Yamamoto, Masahiro*; Okumi, Shoji*; Furuta, Fumio*; Miyamoto, Masaharu*; Kuwahara, Makoto*; Yamamoto, Naoto*; Naniwa, Kenichi*; Watanabe, Osamu*; et al.
Journal of Applied Physics, 97(9), p.094907_1 - 094907_6, 2005/05
Times Cited Count：68 Percentile：87.78(Physics, Applied)no abstracts in English
Re-MAG3-A7 anti-colorectal cancer monoclonal antibody; Comparison with 
I-counterpartKinuya, Seigo*; Yokoyama, Kunihiko*; Kobayashi, Katsutoshi; Motoishi, Shoji; Onoma, Katsuyuki; Watanabe, Naoto*; Shuke, Noriyuki*; Bunko, Hisashi*; Nichigishi, Takatoshi*; Tonami, Norihisa*
Annals of Nuclear Medicine, 15(3), p.199 - 202, 2001/06
Times Cited Count：10 Percentile：33.17(Radiology, Nuclear Medicine & Medical Imaging)no abstracts in English
Cs(n,)
CsSekine, Toshiaki; ; Kobayashi, Katsutoshi; Harada, Hideo*; Watanabe, Hisashi*; Kato, Toshio*
Journal of Nuclear Science and Technology, 30(11), p.1099 - 1106, 1993/11
Times Cited Count：30 Percentile：91.29(Nuclear Science & Technology)no abstracts in English
Cs(n,)CsSekine, Toshiaki; ; Kobayashi, Katsutoshi; Harada, Hideo*; Watanabe, Hisashi*; Kato, Toshio*
Proc. of the Nuclear Data for Science and Technology, p.57 - 58, 1992/00
no abstracts in English
Cs(n,)CsSekine, Toshiaki*; Hatsukawa, Yuichi*; Kobayashi, Katsunori*; Harada, Hideo; Watanabe, Hisashi; Kato, Toshio*
Proceedings of International Conference on Nuclear Data for Science and Technology, p.57 - 58, 1992/00
no abstracts in English
