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Taguchi, Tomitsugu; Igawa, Naoki; Yamamoto, Hiroyuki; Shamoto, Shinichi; Jitsukawa, Shiro
Physica E, 28(4), p.431 - 438, 2005/09
Times Cited Count：83 Percentile：91.14(Nanoscience & Nanotechnology)Preparation conditions of single-phase SiC nanotubes and C-SiC coaxial nanotubes were investigated. The characterization of single-phase SiC nanotubes and C-SiC coaxial nanotubes were carried out. The SiC nanowires, which were made of the catenated SiC grains of 50-200 nm in diameter, were obtained in carbon nanotubes reacted at 1450 
C. The only C-SiC coaxial nanotubes were formed at 1300 C. A few single-phase SiC nantoubes were synthesized at 1200 C for 100 h. More than half number of nanotubes reacted at 1200 C for 100 h were altered to single-phase SiC nantoubes by heat treatment of 600 C for 1h in air since the remained carbon was removed. The energy dispersive X-ray spectroscopy analysis revealed that the atomic ratio of Si to C in single-phase SiC nanotubes was almost 1; these single-phase SiC nanotubes consisted of near-stoichiometric SiC grains.
Soyama, Kazuhiko; Matsubayashi, Masahito; Masaoka, Sei; Nakamura, Tatsuya; Matsumura, Tatsuya*; Kinoshita, Katsuyuki*
JAERI-Research 2003-032, 22 Pages, 2004/03
JAERI-Research-2003-032.pdf:1.83MB
The neutron zooming tube has been developed using electronic zooming TV readout system for an X-ray microscope. This system consists of the photocathode, the electro-magnetic coil assembly and the CCD TV camera etc.. The photocathode consists of transmission type CsI layer in combination with neutron converters such as Gd foil. The system position sensitive resolution of 20
m has been obtained using neutron converter. We have found that it is determined from the distance between the CsI layer and the neutron converter, then the limiting resolution could be improved.
Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Yoshida, Tadashi
Nuclear Instruments and Methods in Physics Research A, 513(3), p.429 - 438, 2003/11
Times Cited Count：3 Percentile：27.69(Instruments & Instrumentation)At the JAERI Tandem accelerator, an acceleration tube replacing plan is proceeding to increase the acceleration voltage toward 20 MV. Lengthy conditioning is generally necessary for a large tube system. We had an idea to clean the tubes with high-pressure water-jet rinsing before installation. We cleaned tubes and tested them at 1 MV and 3 MV. The both results exhibited that the voltages went beyond the rated voltages and discharge activities were much less than the old records. During the test of new tubes at 3 MV, the conditioning proceeded well and an extremely stable condition was fulfilled within 24 hours. In conclusion, the cleaning was found to be a very promising way to improve high-voltage performance of the tubes in a large tube system.
Takeuchi, Suehiro; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Ishizaki, Nobuhiro; Matsuda, Makoto; Tsukihashi, Yoshihiro; Kanda, Susumu; Tayama, Hidekazu; Abe, Shinichi; Yoshida, Tadashi
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.308 - 310, 2003/00
no abstracts in English
Sugimoto, Masaki; Idesaki, Akira; Tanaka, Shigeru; Okamura, Kiyohito*
Key Engineering Materials, 247, p.133 - 136, 2003/00
no abstracts in English
Aghamiri, M. S.*; Ukai, Shigeharu*; Ono, Naoko*; Hayashi, Shigenari*; Sowa, Takashi*; Sugawara, Naoya*; Sakamoto, Kan*; Yamashita, Shinichiro
no journal, ,
Both the grain structure and mechanical properties of the fuel cladding tubes are important issues to design the material for high temperature conditions and probable accident of nuclear reactor. In this study, we compared the microstructure and tensile properties of FeCrAl-ODS steels plates and cladding tubes in different extruded, recovered and recrystallized conditions and propose the material for the application.
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Nagakawa, Genta*; Tamaru, Ayaka*; Fukasawa, Tomonori*; Ishigami, Toru*; Fukui, Kunihiro*
no journal, ,
Microwave heating in combination with an external heating source has been used to improve powder properties by compensating for heat transfer losses. However, the external heating source in the microwave irradiation field may degrade the heating elements. A hybrid heating method has been developed to use composite ceramic jacket prepared by adding carbon nanotube (CNT) to alumina. To evaluate the effect of CNT-containing alumina composite ceramic jacket (CNT jacket), experiments were implemented. In both copper nitrate solution and nickel nitrate solution, the time to reach the maximum temperature was earlier when the CNT jacket was used than when the alumina jacket was used. The temperature of the nickel nitrate solution was kept at the maximum temperature when the CNT jacket was used, while the temperature tended to decrease after reaching to 280C when the alumina jacket was used. The hybrid heating method using the CNT jacket can obtain metal oxides.
