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Ikeda, Yoshimasa*; Taketani, Atsushi*; Takamura, Masato*; Sunaga, Hideyuki*; Kumagai, Masayoshi*; Oba, Yojiro*; Otake, Yoshie*; Suzuki, Hiroshi
Nuclear Instruments and Methods in Physics Research A, 833, p.61 - 67, 2016/10
Times Cited Count：38 Percentile：96.62(Instruments & Instrumentation)A compact accelerator-based neutron source has been lately discussed on engineering applications such as transmission imaging and small angle scattering as well as reflectometry. However, nobody considers using it for neutron diffraction experiment because of its low neutron flux. In this study, therefore, the neutron diffraction experiments are carried out using Riken Accelerator-driven Compact Neutron Source (RANS), to clarify the capability of the compact neutron source for neutron engineering diffraction. The diffraction pattern from a ferritic steel was successfully measured by suitable arrangement of the optical system to reduce the background noise, and it was confirmed that the recognizable diffraction pattern can be measured by the large sampling volume with 10 mm in cubic for an acceptable measurement time, i.e. 10 minutes. The minimum resolution of the 110 reflection for RANS is approximately 2.5 % at 8 
s of the proton pulse width, which is insufficient to perform the strain measurement by neutron diffraction. The moderation time width at the wavelength corresponding to the 110 reflection is estimated to be approximately 30 s, which is the most dominant factor to determine the resolution. Therefore, refinements of the moderator system to decrease the moderation time are important to improve the resolution of the diffraction experiment using the compact neutron source. In contrast, the texture evolution due to plastic deformation was successfully observed by measuring a change in the diffraction peak intensity by RANS. Furthermore, the volume fraction of the austenite phase was also successfully evaluated by fitting the diffraction pattern using a Rietveld code. Consequently, RANS was proved to be capable for neutron engineering diffraction aiming for the easy access measurement of the texture and the amount of retained austenite.
Takamura, Masato*; Ikeda, Yoshimasa*; Sunaga, Hideyuki*; Taketani, Atsushi*; Otake, Yoshie*; Suzuki, Hiroshi; Kumagai, Masayoshi*; Hama, Takayuki*; Oba, Yojiro*
Journal of Physics; Conference Series, 734(Part B), p.032047_1 - 032047_4, 2016/08
Times Cited Count：5 Percentile：86.44(Physics, Applied)Neutron diffraction is well known to be a useful technique for measuring a bulk texture of metallic materials taking advantage of a large penetration depth of the neutron beam. However, this technique has not been widely utilized for the texture measurement because large facilities like a reactor or a large accelerator are required in general. In contrast, RANS (Riken Accelerator-driven Compact Neutron Source) has been developed as a neutron source which can be used easily in laboratories. In this study, texture evolution in steel sheets with plastic deformation was successfully measured using RANS. The results show the capability of the compact neutron source for the analysis of the crystal structure of metallic materials, which leads us to a better understanding of plastic deformation behavior.
Kawahata, Kazuo*; Kawano, Yasunori; Kusama, Yoshinori; Mase, Atsushi*; Sasao, Mamiko*; Ide, Shunsuke; Oikawa, Toshihiro; Suzuki, Takahiro; Takase, Yuichi*; Nakamura, Yukio*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 84(5), p.297 - 298, 2008/05
no abstracts in English
Sasao, Mamiko*; Kusama, Yoshinori; Kawano, Yasunori; Kawahata, Kazuo*; Mase, Atsushi*; Sugie, Tatsuo; Fujita, Takaaki; Fukuda, Takeshi*; Fukuyama, Atsushi*; Sakamoto, Yoshiteru; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(9), p.779 - 782, 2007/09
This is a report of highlights from 2007 spring meetings of seven Topical Groups (TG) of International Tokamak Physics Activity (ITPA). In each meeting, high priority issues in physics of International Thermonuclear Experimental Reactor (ITER) and other burning plasma experiments have been discussed and investigated. Twenty-seven scientists from Japan have participated in those meetings. Dates and places of the meetings are shown below. (1) Diagnostics TG: 26-30 March, Princeton (USA), (2) Transport Physics TG: 7-10 May, Lausanne (Switzerland), (3) Confinement Database and Modeling TG: 7-10 May, Lausanne (Switzerland), (4) Edge Pedestal Physics TG: 7-10 May, Garching (Germany) (5) Steady State Operation TG: 9-11 May, Daejeon (South Korea), (6)MHD TG: 21-24 May, San Diego (USA), (7) Scrape-off-layer and Divertor Physics TG: 7-10 May, Garching (Germany).
Kawahata, Kazuo*; Kawano, Yasunori; Kusama, Yoshinori; Mase, Atsushi*; Sasao, Mamiko*; Sugie, Tatsuo; Fujita, Takaaki; Fukuda, Takeshi*; Fukuyama, Atsushi*; Sakamoto, Yoshiteru; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(2), p.195 - 198, 2007/02
no abstracts in English
Asakura, Nobuyuki; Kato, Takako*; Nakano, Tomohide; Takamura, Shuichi*; Tanabe, Tetsuo*; Iio, Shunji*; Nakajima, Noriyoshi*; Ono, Yasushi*; Ozeki, Takahisa; Takechi, Manabu; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 82(7), p.448 - 450, 2006/07
no abstracts in English
Sugita, Takeshi*; Torii, Tatsuo; Takamura, Atsushi*
KEK Proceedings 2005-10 (CD-ROM), p.7 - 21, 2005/11
In order to calculate particle transport easily even in the case with various complex geometrical configurations, we have developed a CG (Combinatorial Geometry) user-routine in the EGS5 code. Furthermore, we have improved this routine for speed-up of the calculation. As the result, the calculation speed is several times faster than the original ones speed, and comparable with the speed with the non-CG routine.
Kawano, Yasunori; Kawahata, Kazuo*; Kusama, Yoshinori; Sasao, Mamiko*; Sugie, Tatsuo; Mase, Atsushi*; Asakura, Nobuyuki; Kato, Takako*; Takamura, Shuichi*; Tanabe, Tetsuo*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 81(2), p.128 - 130, 2005/02
no abstracts in English
Asakura, Nobuyuki; Kato, Takako*; Takamura, Shuichi*; Tanabe, Tetsuo*; Higashijima, Satoru; Iio, Shunji*; Ozeki, Takahisa; Ono, Yasushi*; Kawano, Yasunori; Nakajima, Noriyoshi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 79(11), p.1194 - 1196, 2003/11
The ITPA (International Tokamak Physics Activity) meeting was held at Scientific Educational Center of Ioffe Institute (St. Petersburg) in Russia. In the meeting, topical physics group meetings of "Scrape-off-layer and Divertor Physics", "MHD, Disruptions and Control", "Energetic Particles, Heating and Steady State Operation", and "Diagnostics" were carried out. The joint meeting for plasma control was also held. In getting many participants from Japan, Europe, Russia, ITER international team, U.S.A. and China (observer), the active discussions were carried out. The outline of discussions in each topical group and in the plasma control joint meeting is reported here.
Ogawa, Yuichi*; Takizuka, Tomonori; Miura, Yukitoshi; Toi, Kazuo*; Fukuda, Takeshi; Wakatani, Masahiro*; Ide, Shunsuke; Takase, Yuichi*; Tobita, Kenji; Fukuyama, Atsushi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 77(10), p.1042 - 1048, 2001/10
no abstracts in English
Toi, Kazuo*; Fukuda, Takeshi; Wakatani, Masahiro*; Ogawa, Yuichi*; Takizuka, Tomonori; Miura, Yukitoshi; Ide, Shunsuke; Takase, Yuichi*; Tobita, Kenji; Fukuyama, Atsushi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 77(2), p.184 - 191, 2001/02
no abstracts in English
-ray spectrometer based on the representative point methodSaegusa, Jun; Ogose, Hitoshi; Takamura, Atsushi*; Sugita, Takeshi*
no journal, ,
The representative point method is an efficiency calibration method for a -ray spectrometer. A calculation code system, CREPT-MCNP, for implementing the method has been newly developed. CREPT-MCNP can be operated under the Windows PC environment as a GUI based application. The code system estimates the position of the representative point which is intrinsic to each shape of volume sample, and also gives the self-absorption factors to make correction on the efficiencies measured at the representative point with a standard point source. It can deal with photons between 20 keV and 2 MeV with p- or n-type germanium semiconductor detectors.
Takamura, Atsushi; Shimada, Taro; Oshima, Soichiro; Uno, Yuichi; Gunji, Soichi; Ito, Takeshi; Sukegawa, Takenori; Nakayama, Shinichi
no journal, ,
no abstracts in English
Takamura, Atsushi; Shimada, Taro; Oshima, Soichiro; Uno, Yuichi; Gunji, Soichi*; Ito, Takeshi; Sukegawa, Takenori; Tanaka, Tadao; Nakayama, Shinichi
no journal, ,
no abstracts in English
Shimada, Taro; Takamura, Atsushi; Oshima, Soichiro; Uno, Yuichi; Gunji, Soichi*; Ito, Takeshi; Sukegawa, Takenori; Tanaka, Tadao; Nakayama, Shinichi
no journal, ,
no abstracts in English
Sukegawa, Takenori; Shimada, Taro; Uno, Yuichi; Oshima, Soichiro; Ito, Takeshi; Takamura, Atsushi; Tanaka, Tadao; Nakayama, Shinichi
no journal, ,
no abstracts in English
Shimada, Taro; Takamura, Atsushi*; Kamiya, Atsushi*; Sukegawa, Takenori; Tanaka, Tadao
no journal, ,
Dispersion ratios, size distribution of particles and filtration efficiencies were measured when piping for reactor cooling system at Fugen reactor was segmented in the contamination control enclosure. Dispersion ratio of Co-60 was observed to be 18 to 23% for normal piping and that to be 34 to 43% for vertically segmented piping, which was half of the normal. Filtration efficiency of pre-filter was observed to be 55 to 80%, while particles smaller than 1micrometer were not able to be collected. It was confirmed that the filtration efficiency of HEPA filter was more than 99.9% for Co-60.
