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Yoshida, Kensuke*; Fujioka, Shinsuke*; Higashiguchi, Takeshi*; Ugomori, Teruyuki*; Tanaka, Nozomi*; Kawasaki, Masato*; Suzuki, Yuhei*; Suzuki, Chihiro*; Tomita, Kentaro*; Hirose, Ryoichi*; et al.
Applied Physics Letters, 106(12), p.121109_1 - 121109_5, 2015/03
Times Cited Count：8 Percentile：35.86(Physics, Applied)Yoshida, Kensuke*; Fujioka, Shinsuke*; Higashiguchi, Takeshi*; Ugomori, Teruyuki*; Tanaka, Nozomi*; Ohashi, Hayato*; Kawasaki, Masato*; Suzuki, Yuhei*; Suzuki, Chihiro*; Tomita, Kentaro*; et al.
Applied Physics Express, 7(8), p.086202_1 - 086202_4, 2014/08
Times Cited Count：28 Percentile：74.83(Physics, Applied)We demonstrate high conversion efficiency for extreme ultraviolet (EUV) emission at 6.5-6.7 nm from multiple laser beam-produced one-dimensional spherical plasmas. Multiply charged-state ions produce strong resonance emission lines, which combine to yield intense unresolved transition arrays in Gd, Tb, and Mo. The maximum in-band EUV conversion efficiency was observed to be 0.8%, which is one of the highest values ever reported due to the reduction of plasma expansion loss.
Sumita, Junya; Shibata, Taiju; Sawa, Kazuhiro; Fujita, Ichiro; Ohashi, Jun*; Takizawa, Kentaro*; Kim, W.*; Park, J.*
Ceramic Materials for Energy Applications; Ceramic Engineering and Science Proceedings, Vol.32, No.9, p.1 - 12, 2011/11
Since the temperature condition in Very High Temperature Reactor (VHTR), one of the Generation-IV reactor systems, is severe, the application of heat-resistant carbon fiber reinforced carbon matrix composite (C/C composite) for control rod elements is one of the important subjects for the VHTR development. JAEA focuses on the application of two-dimensional (2D-) C/C composites for control rod. The 2D-C/C composite has an anisotropy in properties for parallel and perpendicular to lamina directions. Irradiation effects of the 2D-C/C composite also show anisotropic behavior. It is hence important to consider the anisotropy in control rod design. To investigate the irradiation effects of the 2D-C/C composite on properties, irradiation test and post irradiation examination (PIE) were carried out and the irradiation effects were evaluated for the both directions. Since the C/C composite is composed of fibers and matrix, this geometry should be considered to evaluate the crack propagation in the composite. To assess the fracture behavior with crack propagation, bending test was carried out assuming a crack in the control rod and cracks in specimens were observed. This paper describes the irradiation effects of the 2D-C/C composite based on the PIE results considering the anisotropy. The evaluation results on equivalent fracture toughness and fracture mechanism are also discussed.
Jo, Takahisa; Goto, Takehiro; Yabuki, Kentaro; Ikegami, Kazunori; Miyagawa, Takayuki; Mori, Tetsuya; Kubo, Atsuhiko; Kitano, Akihiro; Nakagawa, Hiroki; Kawamura, Yoshiaki; et al.
JAEA-Technology 2010-052, 84 Pages, 2011/03
JAEA-Technology-2010-052.pdf:17.14MB
The prototype fast breeder reactor MONJU resumed the System Startup Test (SST) on May 6th 2010 after five months and fourteen years shutdown since the sodium leakage of the secondary heat transport system on December 1995. Core Confirmation Test (CCT) is the first step of SST, which consists of three steps. CCT was finished on July 22nd after 78 days tests. CCT is composed 20 test items including control rods' worth evaluation, radiation dose measurement etc..
Nasu, Shoichi*; Nagata, Shinji*; Yoshii, Kiichiro*; Takahiro, Katsumi*; Kikuchi, Naoto*; Kusano, Eiji*; Moto, Shintaro*; Yamaguchi, Sadae*; Ohashi, Kentaro*; Noda, Kenji; et al.
Funtai Oyobi Fummatsu Yakin, 52(6), p.427 - 429, 2005/06
no abstracts in English
Otsuki, Ryusei*; Nasu, Shoichi*; Fujimori, Ryosuke*; Anada, Kinji*; Ohashi, Kentaro*; Yamamoto, Ryoichi*; Fujii, Kimio; Okubo, Keisuke*
Funtai Oyobi Fummatsu Yakin, 51(8), p.622 - 625, 2004/08
Effects of carbon materials on weight yield of (C
+C
) and weight ratios of C to (C+C) in soot were examined by the Joule resistive heating of four kinds of carbon materials at He gas pressures from 0.7
10
8.010Pa for collector radii of 45, 50 and 55mm. The yields were in the range of 1 to 8% for graphite with hexagonal lattice, and better than those for glassy carbon. The most effective He gas pressure for the fullerene yield were in the range of 4.05.310Pa. Any collector radii dependence of the yields was not observed. The weight ratios of C to (C+C) were about 60 to 70%, and showed neither He gas pressure depenndennce nor collector radii depenndence four kinds of carbon materials.
Otsuki, Ryusei*; Nasu, Shoichi*; Ohashi, Kentaro*; Yamamoto, Ryoichi*; Fujii, Kimio; Okubo, Keisuke*
Funtai Oyobi Fummatsu Yakin, 51(8), p.626 - 629, 2004/08
The He, Ar and the Penning gas pressureeffects on the preparation yieldsof the fullerenes were investigated by means of the arc discharge method using graphite(PGX) anode buried in a tungsten rod and tungsten cathode for collector radii of 50mm. The maximum yield showed about 13-14 % at 67KPa in He gas. The yields in the mixtures of He and Ne gases (the Penning effect) were similar to those obtained in He gas. Weight ratios of C to (C+C) were about 20% in Ar gas, while those in He and Penning gas were about 60%. Ultra sonic vibration was effective to separate C from soot.
Otsuki, Ryusei*; Nasu, Shoichi*; Matsushita, Masaki*; Fujii, Kimio; Ohashi, Kentaro*; Yamamoto, Ryoichi*
Funtai Oyobi Fummatsu Yakin, 51(8), p.633 - 634, 2004/08
We examined effects of deposition temperatures and collector radii onthe yields of fullerenes by arc discharge. Yields of fullerenes were 7-10%, 4-6% and 0.5-1% in the liquid nitrogen-cooling, water-cooling, non-cooling, respectively, and were better with a collector radius of 50mm than with that of 30mm. The weight ratios of C/C are about one for all runs of experiments.
Mori, Tetsuya; Morohashi, Yuko; Maruyama, Shuhei; Kasahara, Hideyuki; Yabuki, Kentaro; Okawachi, Yasushi
no journal, ,
no abstracts in English
Morohashi, Yuko; Mori, Tetsuya; Maruyama, Shuhei; Kasahara, Hideyuki; Yabuki, Kentaro; Okawachi, Yasushi
no journal, ,
no abstracts in English
Mori, Tetsuya; Takano, Kazuya; Kitano, Akihiro; Morohashi, Yuko; Kato, Yuko; Yabuki, Kentaro; Miyagawa, Takayuki; Okawachi, Yasushi; Hazama, Taira
no journal, ,
Monju restarted safely on May 6, 2010 after 14 years and 5 months suspension. Core Confirmation Test was performed until July 22. The core fuel contains Am-241 because Pu-241 (half-life 14 years) decayed during 14.4 years suspension. Therefore, physics data of the core containing Am-241 are obtained. The mainly test items are criticality, control rod worth and isothermal temperature coefficient. In the criticality, the measured CR position at the criticality was confirmed to be within the predicted CR position range. Criticality was predicted in good accuracy. In the control rod worth measurement, CR worth of CCR1 was measured by the period method. CR worth of other CR was measured by the balancing method. In the isothermal temperature coefficient measurement, the measured value was a little bit smaller than that of the previous test due to the accumulation of Am-241, the decay of Pu-241, and other composition change by refuelling.
Beppu, Shinji; Onoe, Hironori; Kohashi, Akio; Ueno, Tetsuro; Takayasu, Kentaro; Takeuchi, Ryuji; Ishibashi, Masayuki; Sawada, Atsushi
no journal, ,
no abstracts in English
Keya, Hiromichi; Takayasu, Kentaro; Kohashi, Akio; Onoe, Hironori; Takeuchi, Ryuji
no journal, ,
no abstracts in English
