Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shimomura, Koichiro*; Koda, Akihiro*; Pant, A. D.*; Sunagawa, Hikaru*; Fujimori, Hiroshi*; Umegaki, Izumi*; Nakamura, Jumpei*; Fujihara, Masayoshi; Tampo, Motonobu*; Kawamura, Naritoshi*; et al.
Interactions (Internet), 245(1), p.31_1 - 31_6, 2024/12
Shishido, Hiroaki*; Nishimura, Kazuma*; Vu, TheDang*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; et al.
IEEE Transactions on Applied Superconductivity, 31(9), p.2400505_1 - 2400505_5, 2021/12
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)In this study, we employed a superconducting detector, current-biased kinetic-inductance detector (CB-KID) for neutron imaging using a pulsed neutron source. We employed the delay-line method, and high spatial resolution imaging with only four reading channels was achieved. We also performed wavelength-resolved neutron imaging by the time-of-flight method. We obtained the neutron transmission images of a Gd-Al alloy sample, inside which single crystals of GdAl
were grown, using the delay-line CB-KID. Single crystals were well imaged, in both shapes and distributions, throughout the Al-Gd alloy. We identified Gd nuclei via neutron transmissions that exhibited characteristic suppression above the neutron wavelength of 0.03 nm. In addition, the 
Gd resonance dip, a dip structure of the transmission caused by the nuclear reaction between an isotope and neutrons, was observed even when the number of events was summed over a limited area of 15 
m 
12 m. Gd selective imaging was performed using the resonance dip of Gd, and it showed clear Gd distribution even with a limited neutron wavelength range of 1 pm.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count：13 Percentile：99.06(Quantum Science & Technology)Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Times Cited Count：7 Percentile：90.97(Physics, Atomic, Molecular & Chemical)Wakai, Eiichi; Kikuchi, Takayuki; Kim, B.*; Kimura, Akihiko*; Nogami, Shuhei*; Hasegawa, Akira*; Nishimura, Arata*; Soldaini, M.*; Yamamoto, Michiyoshi*; Knaster, J.*
Fusion Engineering and Design, 98-99, p.2089 - 2093, 2015/10
Times Cited Count：16 Percentile：77.56(Nuclear Science & Technology)Wakai, Eiichi; Kim, B. J.; Nozawa, Takashi; Kikuchi, Takayuki; Hirano, Michiko*; Kimura, Akihiko*; Kasada, Ryuta*; Yokomine, Takehiko*; Yoshida, Takahide*; Nogami, Shuhei*; et al.
Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 6 Pages, 2013/03
Wakai, Eiichi; Kikuchi, Takayuki; Kogawara, Takafumi; Kimura, Haruyuki; Yokomine, Takehiko*; Kimura, Akihiko*; Nogami, Shuhei*; Kurishita, Hiroaki*; Saito, Masahiro*; Nishimura, Arata*; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 6 Pages, 2011/03
Japanese activities of test facilities in IFMIF-EVEDA (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities) project have three subjects of engineering design of post irradiation examination (PIE) facilities, small specimen test technique (SSTT), and engineering design of high flux test module (HFTM), and this paper is summarized about present status. Functional analysis and design of 2-D and 3-D models of PIE facility were performed. In HFTM, as materials of heater, W-3Re alloy and/or SiC/SiC composite were selected in the points of high temperature materials, fabrication technology and some suitable properties such as resistance of thermal shock, high temperature re-crystallization, ductility, resistance of irradiation degradation, and low-activation. In SSTT, a test machine of fracture toughness was designed and developed for small specimens with 10 mm square, and it had high accuracy controllability for stress and displacement.
Zhang, Z.*; Nishikino, Masaharu; Nishimura, Hiroaki*; Kawachi, Tetsuya; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Ogura, Koichi; Yogo, Akifumi; Okano, Yasuaki*; et al.
Optics Express (Internet), 19(5), p.4560 - 4565, 2011/02
Times Cited Count：19 Percentile：66.78(Optics)
line emission from Mo and Ag plate were experimentally studied by using ultra-high intensity, clean femtosecond laser pulses. Absolutely yield of X-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significant enhancement of yields were obtained for both Mo and Ag with higher contrast ratios and high irradiance. The conversion efficiencies of 4.28 10
/sr for Mo and 4.84 10/sr for Ag, the highest values ever obtained, have been demonstarted with the contrast ratio of 10
to 10
.
Ohashi, Hayato*; Suda, Shintaro*; Tanuma, Hajime*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Kai, Takeshi; Sasaki, Akira; Sakaue, Hiroyuki*; Nakamura, Nobuyuki*; et al.
Journal of Physics; Conference Series, 163, p.012071_1 - 012071_4, 2009/06
Times Cited Count：7 Percentile：89.27(Physics, Multidisciplinary)Extreme ultra-violet (EUV) emission spectra of multiply charged tin ions were measured in the wavelength range of 10-22 nm following charge exchange collisions or the electron impact excitation of tin ions. In charge exchange collisions, we observed both the resonance lines and the emission lines corresponding to the transitions between the excited states. On the other hand, we observed mainly the resonance lines in the electron impact experiments. We can distinguish the resonance lines from other emission lines in the charge exchange spectrum by comparison with the emission lines in the electron impact spectrum.
Honda, Akira; Masuda, Kaoru*; Imakita, Tsuyoshi*; Kato, Osamu*; Nishimura, Tsutomu*
Zairyo To Kankyo, 58(5), p.182 - 189, 2009/05
Interaction between carbon steel and nitrate was modeled using the mixed potential concept. Carbon steel was selected as an example of metal components in the repository of radioactive waste. The nitrate reduction accompanied by the corrosion of carbon steel was modeled as a reaction series such as nitrate - nitrite - ammonia. The sum of the current of the reaction series of nitrate - nitrite - ammonia and that of water reduction was assumed to balance with the corrosion current of carbon steel. The input parameters for this kinetic model were determined by electrochemical measurement and immersion test. The results of the immersion test can be interpreted by the analyses of the model.
Nishihara, Katsunobu*; Sunahara, Atsushi*; Sasaki, Akira; Tanuma, Hajime*; Koike, Fumihiro*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Shimada, Yoshinori*
Reza Kenkyu, 36(11), p.690 - 699, 2008/11
The critical issue for realization of a laser produced plasma (LPP) extreme ultraviolet (EUV) light source is the conversion efficiency (CE) from incident laser power to EUV radiation of 13.5 nm wavelength. From an atomic physics, we show that tin is the most suitable radiation material compared with xenon and lithium. We also show the optimization of laser and target conditions to obtain high CE using a power balance model. We propose a double-pulse irradiation scheme for high CE using a carbon dioxides laser and a droplet target.
Izawa, Yasukazu*; Nishihara, Katsunobu*; Tanuma, Hajime*; Sasaki, Akira; Murakami, Masakatsu*; Sunahara, Atsushi*; Nishimura, Hiroaki*; Fujioka, Shinsuke*; Aota, Tatsuya*; Shimada, Yoshinori*; et al.
Journal of Physics; Conference Series, 112, p.042047_1 - 042047_4, 2008/00
Times Cited Count：8 Percentile：93.57(Physics, Fluids & Plasmas)In the development of a high power EUV source used in the EUV lithography system, we have been constructed EUV database of laser-produced tin plasma by the theoretical and experimental studies. On the basis of our understanding, the optimum conditions of lasers and plasmas were clarified, and we proposed the guidelines of laser plasma to obtain clean, efficient and high power EUV source for the practical EUV lithography system. In parallel to such studies, novel targets and high power laser system to generate the optimized EUV source plasma have been developed.
Nishihara, Katsunobu*; Sunahara, Atsushi*; Sasaki, Akira; Nunami, Masanori*; Tanuma, Hajime*; Fujioka, Shinsuke*; Shimada, Yoshinori*; Fujima, Kazumi*; Furukawa, Hiroyuki*; Kato, Takako*; et al.
Physics of Plasmas, 15(5), p.056708_1 - 056708_11, 2008/00
Times Cited Count：122 Percentile：97.46(Physics, Fluids & Plasmas)Sunahara, Atsushi*; Sasaki, Akira; Tanuma, Hajime*; Nishihara, Katsunobu*; Nishikawa, Takeshi*; Koike, Fumihiro*; Fujioka, Shinsuke*; Aota, Tatsuya*; Yamaura, Michiteru*; Shimada, Yoshinori*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(11), p.920 - 926, 2007/11
We study the EUV emission from laser produced Sn plasmas using the 1D and 2D radiation hydrodynamics simulation, for the development of EUV source for the next generation semiconductor lithography. The opacity and emissivity of the plasma used in the simulation are calculated by a detailed atomic model, with the accurate wavelength of emission lines obtained from the detailed spectroscopic measurements. Calculation is shown to reproduce the experimental spectrum and conversion efficiency reasonably, including the effect of photo pumping which modifies the EUV emission spectrum in the case with a long scale length of the plasmas.
Al conductor for coils with react-and-wind methodKizu, Kaname; Tsuchiya, Katsuhiko; Shimada, Katsuhiro; Ando, Toshinari*; Hishinuma, Yoshimitsu*; Koizumi, Norikiyo; Matsukawa, Makoto; Miura, Yushi*; Nishimura, Arata*; Okuno, Kiyoshi; et al.
Fusion Engineering and Design, 82(5-14), p.1493 - 1499, 2007/10
Times Cited Count：3 Percentile：25.51(Nuclear Science & Technology)no abstracts in English
Ashikawa, Naoko*; Kizu, Kaname; Yagyu, Junichi; Nakahata, Toshihiko*; Nobuta, Yuji; Nishimura, Kiyohiko*; Yoshikawa, Akira*; Ishimoto, Yuki*; Oya, Yasuhisa*; Okuno, Kenji*; et al.
Journal of Nuclear Materials, 363-365, p.1352 - 1357, 2007/06
Times Cited Count：10 Percentile：58.16(Materials Science, Multidisciplinary)no abstracts in English
Nishimura, Masahiro; Futagami, Satoshi; Ohno, Shuji; Miyahara, Shinya
Nihon Genshiryoku Gakkai Wabun Rombunshi, 6(2), p.149 - 160, 2007/06
no abstracts in English
Tomita, Yutaka; Morihira, Masayuki; Tamaki, Yoshihisa*; Nishimura, Kazuhisa*; Shoji, Shuichi*; Kihara, Yoshiyuki; Kase, Takeshi; Koizumi, Tsutomu
JAEA-Research 2006-088, 95 Pages, 2007/01
JAEA-Research-2006-088.pdf:23.02MB
JAEA has developed sphere-pac fuels in the feasibility study on commercialized FBR cycle systems as one of the candidates for low decontamination TRU fuels. Optimization of the fabrication condition for coarse spheres, development of an improved external gelation process, and examination of peculiar problems for the low decontamination fuel were carried out in Phase II. The results are shown as follows. (1) Fabrication condition of coarse spheres was optimized. (2) Feasibility of the improved external gelation process was confirmed. (3) Rare earth elements did not bring any problem for the characteristic of spheres and fabrication condition. (4) Radiation resistant data of the feed solution was acquired. Results of tests show the feasibility of the external gelation process for the low decontamination TRU fuel microsphere fabrication.
Honda, Akira; Kato, Takashi; Tateishi, Tsuyoshi*; Imakita, Tsuyoshi*; Masuda, Kaoru*; Kato, Osamu*; Nishimura, Tsutomu*
Zairyo To Kankyo, 55(10), p.458 - 465, 2006/10
Migration of radioactive material can be affected by the redox condition and the concentration of ligands in the repository of radioactive waste. It is possible that radioactive waste contains nitrate which can affect the migration behavior of radioactive nuclides by both changing the redox condition of the environment and acting as a ligand. On the other hand, several researchers observed the reduction of nitrate ions in ammonia due to the iron. Ammonia has a potential to ligand for radioactive nuclides. Nitrate can also affect the rate of hydrogen gas evolution accompanied by metal corrosion through changing the rest potential of metal by its oxidizing nature. Carbon steel was, therefore, immersed in an aqueous solution of sodium nitrate in a closed system for observing both the chemical interaction between metal and nitrate, and the effect of nitrate on the hydrogen gas evolution rate. The experimental pH range of the solution was 10.0-13.5 which corresponds to the pH range of pore fluid of cementitious material. The cathodic current density shows a Tafel equation type potential dependency in the aqueous solution containing nitrate or nitrite. In spite of the acceleration of cathodic reaction due to the existence of nitrate, the corrosion rates of carbon steel were not accelerated in the nitrate solutions. This fact suggests that the system is controlled by the anodic reaction. The nitrate reduction accompanied by the corrosion of carbon steel is considered to be a series reaction such as nitrate nitrite ammonia. The nitrate reduction reaction compete with the water reduction reaction within the anodic controlled condition, therefore nitrate strongly reduced the hydrogen evolution rate. The generation rates of ammonia were independent of the concentration of nitrate.
Al strand and cable-in-conduit conductorKizu, Kaname; Tsuchiya, Katsuhiko; Shimada, Katsuhiro; Ando, Toshinari*; Hishinuma, Yoshimitsu*; Koizumi, Norikiyo; Matsukawa, Makoto; Miura, Yushi*; Nishimura, Arata*; Okuno, Kiyoshi; et al.
IEEE Transactions on Applied Superconductivity, 16(2), p.872 - 875, 2006/06
Times Cited Count：1 Percentile：11.95(Engineering, Electrical & Electronic)no abstracts in English
