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Ekins-Daukes, N. J.*; Lee, H. S.*; Sasaki, Takuo*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Agui, Takaaki*; Kamimura, Kunio*; Kaneiwa, Minoru*; Imaizumi, Mitsuru*; et al.
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.87 - 91, 2004/10
no abstracts in English
Hori, Toshihiko*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Hasegawa, Kazuo
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.212 - 214, 2004/08
no abstracts in English
Fujita, Naoki*; Lee, H.-S.*; Okada, Hiroshi*; Wakahara, Akihiro*; Yoshida, Akira*; Oshima, Takeshi; Ito, Hisayoshi
Shingaku Giho, 102(77), p.79 - 84, 2002/05
no abstracts in English
Dharmarasu, N.*; Yamaguchi, Masafumi*; Khan, K.*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Physica B; Condensed Matter, 308-310, p.1181 - 1184, 2001/12
Times Cited Count:7 Percentile:41.38(Physics, Condensed Matter)Carrier concentration and defects in n+/p InGaP irradiated with 100keV-protons (1E10, 5E12 /cm2) were studied.As a result of C-V measurements, the carrier removal rate was estimated to be 6.1E4 /cm2 which was extremely high as compared to 1MeV-electron irradiation case (0.93 /cm). H1 peak whose energy corresponds to Ev+0.90V was obtained from DLTS measurements. This suggests that carrier removal rate in proton-irradiated ones is much higher than that in electron-irradiated ones due to the generation of the defects (H1 peak) which act as majority carrier traps.
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Koizumi, Koichi; Nakahira, Masataka; Takahashi, Hiroyuki*
Fusion Engineering and Design, 58-59, p.869 - 873, 2001/11
Times Cited Count:2 Percentile:19.66(Nuclear Science & Technology)no abstracts in English
Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Nakahira, Masataka
Transactions of 16th International Conference on Structural Mechanics in Reactor Technology (SMiRT-16) (CD-ROM), 8 Pages, 2001/08
Fatigue test of the weldments was performed to investigate their fatigue behavior and the effect of the incomplete penetrations on the fatigue strength. Fatigue crack propagation test of their weld metals was also carried out using CT specimen. By calculating stress intensity factors of the weldments contained the incomplete penetrations and cracks using FEM analysis, the fatigue crack propagation rates of weldments were evaluated and compared those of their weld metals. Fatigue life of the weldments was evaluated based on fracture mechanics to discuss the effect of incomplete penetrations on the fatigue strength. As the results, the incomplete penetration behaved as a crack and most of total fatigue life for the weldment was crack propagation life. The crack propagation rates of weldment were in accordance with those of the weld metals. The fatigue strength of the weldment was considerably lower than that of smoothed specimen. The incomplete penetrations affected greatly the fatigue strength of the weldments even if the depth of incomplete penetrations was small.
Aoyagi, Takayoshi*; *; Mihara, Morihiro; Okutsu, Kazuo*; Maeda, Munehiro*
JNC TN8400 2001-024, 103 Pages, 2001/06
In the disposal concept of TRU waste, concentrated disposal of wastes forms in large cross-section underground cavities is envisaged, because most of TRU waste is no-heat producing in spite of large generated volume as compared with HLW. In the design of engineered barrier system based on large cross-section cavities, it is necessary to consider the long-term mechanical process such as creep displacement of the host rock from the viewpoint of the stability of engineered barrier system. In this study, the long-term creep displacement of the host rock was calculated using the non-linear viscoelasticity model and the effects on the stability of engineered barrier system was evaluated. As a result, in the disposal concept of crystalline rock, no creep displacement occurred at the time after 1 milion year. On the other hand, in the disposal concept of sedimentary rock, creep displacement of 8090mm occurred at the time after 1 milion year. Also, in this calculation, a maximum reduction of 45mm concerned with the thickness of buffer material was estimated. But these values resulted within allowance of design values. Therefore, these results show that the effects of the creep displacement on the stability of engieered barrier system would not be significant.
Izaki, Kenji; Noda, Kimio; ; Kashimuta, Yoshio*
JNC TN8410 2001-005, 30 Pages, 2001/01
Stack monitoring is the most important work in radiation control works. Exhaust monitors used for stack monitoring have the background (which is the counts by natural radio-nuclides) on normal condition, and the values of the background vary with the facilities. Therefore, if the value of background is high, it is difficult to estimate rapidly the radioactive concentration in the exhaust. In order to estimate rapidly the radioactive concentration in exhaust, we analyzed the behavior of natural radioactivity in the facilities and examine the technique fo reducing the value of the background. As a result of the examination, we found that it is possible to estimate rapidly if we change over the monitoring point to immediately after the HEPA filters on the exhaust duct. In this reports, the analyzed results of behavior of natural radio-nuclides in the facilities and the technique for reducing the values of the background are described. To reduce the value of the background has a major effect on not only rapidly estimating the radioactive density in the exhaust but also finding the unusual things on stack monitoring.
Hama, Katsuhiro; Taniguchi, Naoki; Honda, Akira
JNC TN7430 2000-002, 25 Pages, 2001/01
The burial tests of mild steel and pure titanium were performed in a gallery at Tono mine to assess the corrosion resistance of these materials under goundwater environment. Specimens were placed in the container and immersed into groundwater. After the immersion period, the apperance of the surface of these specimens were observed. The corrosion product of mild steel specimen was analysed by various methods. The average corrosion rate of mild steel for 10 years was assessed by the measurement of the weight loss of carbon steel specimen. The results of the test were summerised as follows : (1)The average corrosion rate of mild steel for 10 years was assessed to be 4.36 10mm/y by the weight loss of the specimen. (2)The corrosion product consists of outer porous substance and inner tight corrosion product film. The former contains ferric oxide such as goethite and the latter contains ferrous oxide such as magnetite. (3)The evidence of the initiation of localised corrosion was not observed on the titanium specimens.
Ohno, Shuji; Matsuki, Takuo*
JNC TN9400 2000-106, 132 Pages, 2000/12
Sodium fire analyses were performed on 7 kinds of sodium leak tests using a computer code ASSCOPS which has been developed to evaluate thermal consequences of sodium leak accident in an FBR plant. By the comparison between the calculated and the test results of gas pressure, gas temperature, sodium catch pan temperature, wall temperature, and of oxygen concentration, it was confirmed that the ASSCOPS code and the parameters used in the analysis give valid or conservative results on thermal consequences of sodium leak and fire.
Hama, Katsuhiro; Mitsui, Seiichiro; Aoki, Rieko*; Hirose, Ikuro
JNC TN7430 2000-001, 47 Pages, 2000/12
Long-term immersion tests of glass material at ambient temperature (about 18 C) for 10 years were performed in a gallery at the Tono mine in Japan, in order to assess durability of glass matelial contacted with natural groundwater. The gallery was constructed at a depth of 130 m below ground surface in the Toki Granite. Monolithic glass blocks with dimensions of 10 10 10 mm (cubic type) and of 25 mm in diameter and 8 mm in thickness (disk type: The wall of sample was covered by stainless steel of 1 mm thick.) were used for the tests. Both type of samples with and without clay were put in Teflon vessels, which have small holes on the wall, and inserted into boreholes excavated at the gallery floor. In addition to the immersion tests, static leaching test with cubic type glass and ground water was also performed at the gallery. The samples of each test were collected in time intervals of 6 months, 1 year, 2 years, 3 years and 10 years and were subjected to weight loss measurement and several surface analyses. The results were as follows: (1)Weight losses of each sample were proportional to time intervals. This result is attributable to constant dissolved silica concentration in the ground water during tests. (2)The weight losses of disk type glass were slightly larger than those of cubic type glass. This result is attributable to elemental release from internal cracks of disk type glass, instead of effect of stainless steel on the glass dissolution. (3)The weight losses for the tests with clay were slightly smaller than those for tests without clay. This result is attributable to higher concentration of dissolved silica in pore water of clay.
Takenaga, Hidenobu; Fukuda, Takeshi; Sakurai, Shinji; Hosogane, Nobuyuki; ; Masaki, Kei
Review of Scientific Instruments, 69(9), p.3181 - 3185, 1998/09
Times Cited Count:3 Percentile:35.52(Instruments & Instrumentation)no abstracts in English
Morita, Yosuke; Oshima, Takeshi; Nashiyama, Isamu; *; *; Matsuda, Sumio*
Journal of Applied Physics, 81(9), p.6491 - 6493, 1997/05
Times Cited Count:22 Percentile:71.67(Physics, Applied)no abstracts in English
Oshima, Takeshi; Morita, Yosuke; Nashiyama, Isamu; Kawasaki, Osamu*; Hisamatsu, Tadashi*; Matsuda, Sumio*; Nakao, Tetsuya*; Wako, Yoshihito*
JAERI-Conf 97-003, p.256 - 260, 1997/03
no abstracts in English
Ide, Shunsuke; Nagashima, Keisuke; Naito, Osamu
Purazuma, Kaku Yugo Gakkai-Shi, 73(1), p.112 - 121, 1997/01
no abstracts in English
Ito, Masayuki
Radiation Physics and Chemistry, 47(4), p.607 - 610, 1996/00
Times Cited Count:13 Percentile:72.4(Chemistry, Physical)no abstracts in English
Hinatsu, Yukio
Journal of Alloys and Compounds, 218, p.58 - 63, 1995/00
Times Cited Count:2 Percentile:31.27(Chemistry, Physical)no abstracts in English