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Ogawa, Shuichi*; Tsuda, Yasutaka; Sakamoto, Tetsuya*; Okigawa, Yuki*; Masuzawa, Tomoaki*; Yoshigoe, Akitaka; Abukawa, Tadashi*; Yamada, Takatoshi*
Applied Surface Science, 605, p.154748_1 - 154748_6, 2022/12
Times Cited Count：3 Percentile：48.5(Chemistry, Physical)Immersion of graphene in KOH solution improves its mobility on SiO
/Si wafers. This is thought to be due to electron doping by modification with K atoms, but the K atom concentration C
in the graphene has not been clarified yet. In this study, the C was determined by XPS analysis using high-brilliance synchrotron radiation. The time evolution of C was determined by real-time observation, and the C before irradiation of synchrotron radiation was estimated to be 0.94%. The C 1s spectrum shifted to the low binding energy side with the desorption of K atoms. This indicates that the electron doping concentration into graphene is decreasing, and it is experimentally confirmed that K atoms inject electrons into graphene.
Saito, Shigeru; Wan, T.*; Okubo, Nariaki; Obayashi, Hironari; Watanabe, Nao; Ohdaira, Naoya*; Kinoshita, Hidetaka; Yamaki, Kenichi*; Kita, Satoshi*; Yoshimoto, Hidemitsu*; et al.
JPS Conference Proceedings (Internet), 33, p.011041_1 - 011041_6, 2021/03
An Accelerator Driven System (ADS) for waste transmutation investigated in JAEA employs lead-bismuth eutectic (LBE) as a neutron production target material and coolant. The neutrons are to be produced via the spallation with 1.5 GeV proton beam injection. As materials irradiation data are important for ADS development, JAEA plans to construct an irradiation facility with LBE neutron production target in J-PARC. There are many technical issues on LBE for practical use. In JAEA, various R&Ds are being carried out. Concerning corrosion study, conditioning operation and functional tests of OLLOCHI started. Oxygen concentration control technology has also developing. In the large scale LBE loop experiment, the operation for steady state and transient experiments was performed by using IMMORTAL. In the area of instrument, development of ultrasonic flow meter and freeze seal valve are progressing as a key technology for the LBE loop system. Investigation of behavior of impurities in LBE, which is important for design of the irradiation facility, started. In this paper, the status of the LBE studies and experimental plan will be presented.
Taguchi, Shigeo; Yamamoto, Masahiko; Furuse, Takahiro*; Masaki, Yuji*; Kuno, Takehiko
JAEA-Technology 2018-005, 14 Pages, 2018/06
JAEA-Technology-2018-005.pdf:0.94MB
The method to remove Pu, Am and Np from plutonium nitrate solution recovered from spent nuclear fuel prior to ICP-OES measurement has been developed for the determination of 18 impurity metal elements (Fe, Cr, Ni, Mn, Al, Cd, V, Cu, Si, Zn, Mo, Sn, Ca, Mg, Na, Ag, Pb, B). In this method, two TRU resin packed columns were used for separation. In the first column, Pu and Am were mainly removed by adsorption. The recovered solution from the fist column was added to the second column after reduction of Np, and Am(III) and Np(IV) were removed by adsorption. The Pu nitrate solution (22g/L) of 2mL were treated by proposed method. The alpha emission nuclide was decreased to 
5.8 Bq/mL in a solution diluted to 100mL. As a result of ICP-OES measurement, the recoveries of impurity metals separated by proposed method were almost 100%. This separation scheme can apply to the metal impurity elemental analysis in Pu nitrate solution recovered from spent nuclear fuel.
Kusama, Yoshinori
Purazuma Shindan No Kiso To Oyo, p.195 - 205, 2006/03
no abstracts in English
Takenaga, Hidenobu; Asakura, Nobuyuki; Kubo, Hirotaka; Konoshima, Shigeru; Nakano, Tomohide; Porter, G.*; Rognlien, T.*; Rensink, M.*
Journal of Plasma and Fusion Research SERIES, Vol.7, p.35 - 39, 2006/00
no abstracts in English
-, 4
-, and 6-SiCIsoya, Junichi*; Katagiri, Masayuki*; Umeda, Takahide*; Son, N. T.*; Henry, A.*; Gali, A.*; Morishita, Norio; Oshima, Takeshi; Ito, Hisayoshi; Janz
n, E.*
Materials Science Forum, 527-529, p.593 - 596, 2006/00
no abstracts in English
Takenaga, Hidenobu; Asakura, Nobuyuki; Kubo, Hirotaka; Higashijima, Satoru; Konoshima, Shigeru; Nakano, Tomohide; Oyama, Naoyuki; Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; et al.
Nuclear Fusion, 45(12), p.1618 - 1627, 2005/12
Times Cited Count：18 Percentile：51.39(Physics, Fluids & Plasmas)no abstracts in English
Yamamoto, Masahiro*; Okano, Fuminori; Tsuzuki, Kazuhiro; Ogawa, Hiroaki; Suzuki, Sadaaki; Shibata, Takatoshi
JAERI-Tech 2005-061, 11 Pages, 2005/09
JAERI-Tech-2005-061.pdf:0.94MB
Ferritic steel plates were installed in the JFT-2M vacuum vessel to conduct "the Advanced Material Tokamak Experiments (AMTEX)". A coating device with tri-methyl-bron(TMB)was developed to coat the ferritic steel surface with boron, since the ferritic steel is easy to rust and also has a property to absorb much impurity in the surface. The TMB gas used in the device was diluted with helium gas to 1% for ensuring workers themselves against the toxicity of the TMB. The uniformity and stability of the coated layer have been confirmed through sample tests with a microscope, whose samples had been set in the tokamak vacuum vessel. The coating thickness measured with X-ray photoelectron emission spectroscopy was roughly 130nm. In the plasma experiments after the boron coating, radiation loss in the plasma decreased to 1/3, and oxygen impurity also decreased to 1/10 compared to without the boron coating.
Nakano, Tomohide; Koide, Yoshihiko; Honda, Atsushi; Umeda, Naotaka; Akino, Noboru; Higashijima, Satoru; Takenaga, Hidenobu; Kubo, Hirotaka
Purazuma, Kaku Yugo Gakkai-Shi, 81(9), p.708 - 716, 2005/09
no abstracts in English
Kawano, Yasunori; Nakano, Tomohide; Isayama, Akihiko; Asakura, Nobuyuki; Tamai, Hiroshi; Kubo, Hirotaka; Takenaga, Hidenobu; Bakhtiari, M.; Ide, Shunsuke; Kondoh, Takashi; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 81(8), p.593 - 601, 2005/08
An experiment to investigate mitigation effects of impurity pellet injection on disruption generated runaway electrons was carried out in the JT-60U tokamak device. Deposition of impurity neon pellets into a post-disruption runaway plasma was observed with increment of bulk electron density. At the impurity pellet injection, decay time of runaway current became shorter as factor of 
2. There was an approximately linear relationship between changes in decay rate of runaway current and a photo-neutron signal which indicated loss of runaway electrons from the plasma. Consequently, enhanced loss of runaway electrons from a tokamak plasma, hence mitigation effect on them, by injection of impurity neon pellets was found.
Takenaga, Hidenobu; Asakura, Nobuyuki; Higashijima, Satoru; Nakano, Tomohide; Kubo, Hirotaka; Konoshima, Shigeru; Oyama, Naoyuki; Isayama, Akihiko; Ide, Shunsuke; Fujita, Takaaki; et al.
Journal of Nuclear Materials, 337-339, p.802 - 807, 2005/03
Times Cited Count：14 Percentile：67.84(Materials Science, Multidisciplinary)no abstracts in English
Kawano, Yasunori; Nakano, Tomohide; Isayama, Akihiko; Hatae, Takaki; Konoshima, Shigeru; Oyama, Naoyuki; Kondoh, Takashi; Tamai, Hiroshi; Kubo, Hirotaka; Asakura, Nobuyuki; et al.
Europhysics Conference Abstracts (CD-ROM), 29C, 4 Pages, 2005/00
In order to mitigate the post-disruption runaway electrons, experiments has been carried out with impurity pellet injection. As a result, we have observed the prompt exhaust of the runaway electrons and the reduction of runaway plasma. We have presented one possible explanation for basic behavior of the runaway plasma current that it follows the balance of the avalanche generation of runaway electrons and their slowing down predicted by the model, including effects by synchrotron radiation. On the other hand, standing on the fact that the current quench time is extended by runaway electrons, the experiment for avoiding the current quench by runaway electrons has been carried out. The runaway electrons reinforced the discharge to survive against the low Te of less than several tens eV and an additional impurity pellet injection, and thus the plasma current was maintained and terminated as programmed. To study the dynamics of runaway electrons precisely, a new active and direct diagnostic concept using the laser inverse Compton scattering has been proposed.
Takenaga, Hidenobu; Asakura, Nobuyuki; Kubo, Hirotaka; Higashijima, Satoru; Konoshima, Shigeru; Nakano, Tomohide; Oyama, Naoyuki; Porter, G. D.*; Rognlien, T. D.*; Rensink, M. E.*; et al.
Proceedings of 20th IAEA Fusion Energy Conference (FEC 2004) (CD-ROM), 8 Pages, 2004/11
no abstracts in English
impurity deposition on the JT-60 divertor tilesMasaki, Kei; Yagyu, Junichi; Miyo, Yasuhiko; Goto, Yoshitaka*; Arai, Takashi; Hayashi, Takao; Kodama, Kozo; Sasajima, Tadayuki; Kaminaga, Atsushi; Tanabe, Tetsuo*; et al.
Journal of Nuclear Materials, 329-333(Part1), p.845 - 848, 2004/08
Times Cited Count：0 Percentile：0.01(Materials Science, Multidisciplinary)no abstracts in English
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
Isoya, Junichi*; Oshima, Takeshi; Morishita, Norio; Kamiya, Tomihiro; Ito, Hisayoshi; Yamasaki, Satoshi*
Physica B; Condensed Matter, 340-342, p.903 - 907, 2003/12
Times Cited Count：11 Percentile：51.49(Physics, Condensed Matter)no abstracts in English
Takenaga, Hidenobu; Higashijima, Satoru; Oyama, Naoyuki; Bruskin, L. G.; Koide, Yoshihiko; Ide, Shunsuke; Shirai, Hiroshi; Sakamoto, Yoshiteru; Suzuki, Takahiro; Hill, K. W.*; et al.
Nuclear Fusion, 43(10), p.1235 - 1245, 2003/10
Times Cited Count：71 Percentile：88.64(Physics, Fluids & Plasmas)no abstracts in English
Tsuzuki, Kazuhiro; Kimura, Haruyuki; Kawashima, Hisato; Sato, Masayasu; Kamiya, Kensaku; Shinohara, Koji; Ogawa, Hiroaki; Hoshino, Katsumichi; Bakhtiari, M.; Kasai, Satoshi; et al.
Nuclear Fusion, 43(10), p.1288 - 1293, 2003/10
Times Cited Count：39 Percentile：74.23(Physics, Fluids & Plasmas)no abstracts in English
Laesser, R.*; Gruenhagen, S.*; Kawamura, Yoshinori
Fusion Engineering and Design, 69(1-4), p.813 - 817, 2003/09
Times Cited Count：15 Percentile：69.06(Nuclear Science & Technology)Various analytical techniques exist to determine the compositions of gases handled in the fuel cycle of future fusion machines. Gas chromatography was found to be the most appropriate method. The main disadvantages of conventional gas chromatography were the long retention times for the heavy hydrogen species of more than half an hour. Recent progress in the development of micro-gas chromatography has reduced these retention times to approximately 3 minutes. The usefulness of micro-gas chromatography for the analysis of hydrogen and impurity gas mixtures in the fuel cycle of future fusion machines is presented and the advantages and draw backs are discussed.
Nishiyama, Yutaka; Suzuki, Masahide
Kinzoku, 73(8), p.48 - 52, 2003/08
no abstracts in English
