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Kikuchi, Tatsuya*; Nakajima, Kenji; Kawamura, Seiko; Inamura, Yasuhiro; Nakamura, Mitsutaka; Wakai, Daisuke*; Aoyama, Kazuhiro*; Iwahashi, Takaaki*; Kambara, Wataru*
Physica B; Condensed Matter, 564, p.45 - 53, 2019/07
Times Cited Count：1 Percentile：3.42(Physics, Condensed Matter)Details of the background, that is, unwanted signals accumulated by the data acquisition system of neutron instruments, observed by the cold-neutron chopper spectrometer AMATERAS installed at the Materials and Life Science Experimental Facility at J-PARC are reported. In the design phase of AMATERAS, we carefully considered the achievement of high signal-to-noise ratio, and possible countermeasures were implemented. Actually, recent scientific outputs from AMATERAS indicates that the spectrometer is one of excellent neutron instruments with low background. In spite of that, in nine years of AMATERAS operation, we have encountered unwanted signals due to various reasons, including gamma-rays emitted at materials on or near the beam line including the sample itself, scattered neutrons from the beam line devices, air scattering, electronic noise in data acquisition system, cosmic rays, T0 burst, and other unknown sources. In this report, we discuss the background observed by AMATERAS, especially in the conditions of without samples, comprehensively. The possible sources of these signals and the countermeasures considered against the above sources are discussed, which may be helpful to those who are engaged in other existing or planned neutron-scattering instruments.
neutron diffraction experimentKawasaki, Takuro; Harjo, S.; Gong, W.; Aizawa, Kazuya; Iwahashi, Takaaki; Shi, Z.*; Li, J.*; Tomota, Yo*; Ung
r, T.*
JPS Conference Proceedings (Internet), 8, p.031009_1 - 031009_5, 2015/09
To evaluate the characteristics of the microstructure of materials, such as dislocation density, dislocation character and crystalline size, is as important as elastic strain in order to understand the mechanical properties of the materials. These characteristics can be obtained by analyzing the peak profile in X-ray or neutron diffraction patterns. Although high-penetrability of neutron enables direct observation of the characteristics inside bulky materials, not much research on the microstructure which uses neutron diffraction is available. In the present study, the dislocation characteristics of a martensitic steel during tensile deformation was investigated by in-situ neutron diffraction experiment using Engineering Material Diffractometer TAKUMI at BL19 of MLF, J-PARC and CMWP method. According as the strain increases, significant increasing of the correlation between the dislocations was observed though the increasing of dislocation density is not very much.
Harjo, S.; Aizawa, Kazuya; Abe, Jun*; Gong, W.; Ito, Takayoshi*; Kawasaki, Takuro; Iwahashi, Takaaki
Materials Science Forum, 777, p.12 - 18, 2014/04
Times Cited Count：1 Percentile：49.50(Materials Science, Multidisciplinary)Harjo, S.; Abe, Jun; Aizawa, Kazuya; Gong, W.; Iwahashi, Takaaki
JPS Conference Proceedings (Internet), 1, p.014017_1 - 014017_6, 2014/03
Harada, Masahide; Iwahashi, Takaaki; Harjo, S.; Strasser, P.*
Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.803 - 805, 2011/12
The 2011 off the Pacific coast of Tohoku Earthquake occurred on March 11 in 2011 seriously damaged all J-PARC facilities. In order to restart the beam operation, the alignment work is one of the most important issues. In order to make a plan to re-alignment of devices in MLF, fluctuations of the MLF building and standard points in MLF have been measured with level measurements and traverse measurements. As the results of the level measurements, uneven sinkage of 9 mm in the maximum was found in the MLF building. Large sinkage of about 90 mm and 140 mm was found at two attached buildings. From the measurement after 1.5 month, a sinkage of 1.7 mm in the maximum was found. As the results of the traverse measurements, no large fluctuation in the MLF building was found. However, the attached building was moved away with about 30 mm.
Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Nakamura, Mitsutaka; Kajimoto, Ryoichi; Inamura, Yasuhiro; Takahashi, Nobuaki; Aizawa, Kazuya; Suzuya, Kentaro; Shibata, Kaoru; et al.
Journal of the Physical Society of Japan, 80(Suppl.B), p.SB028_1 - SB028_6, 2011/05
Times Cited Count：154 Percentile：96.19(Physics, Multidisciplinary)AMATERAS is a cold-neutron disk-chopper spectrometer in MLF, J-PARC. The construction of main part of the spectrometer has been completed in spring of 2009. Soon after that, we have started the commissioning work on AMATERAS. The performance of AMATERAS has been examined by test experiments in the course of commissioning. In parallel to these works, we have started the user program on AMATERAS from December 2009 and we are getting scientific results from our spectrometer. In this presentation, we will report the current status of AMATERAS including the results of performance tests and some of examples of scientific outputs.
Harjo, S.; Aizawa, Kazuya; Ito, Takayoshi; Arima, Hiroshi; Abe, Jun; Moriai, Atsushi; Sakasai, Kaoru; Nakamura, Tatsuya; Nakatani, Takeshi; Iwahashi, Takaaki; et al.
Materials Science Forum, 652, p.99 - 104, 2010/09
Times Cited Count：21 Percentile：99.09(Materials Science, Characterization & Testing)The construction of The Engineering Materials Diffractometer, TAKUMI of J-PARC has been finished on March 2009, and the commissioning has been started from September 2008 being parallel with the final stage of the construction. In the commissioning, after checking the validity and the stability of the detectors and the data acquisition system, we checked powder diffraction data of a 2 mm diameter of annealed piano wire with combination of beam collimation (high resolution mode), and confirmed that resolution 
/ of less than 0.2% can be achieved. We also reports preliminary results from researches using TAKUMI.
Miyo, Yasuhiko; Hiratsuka, Hajime; Iwahashi, Takaaki*; Honda, Masao
NIFS-MEMO-36, p.339 - 342, 2002/06
no abstracts in English
Kizu, Kaname; Hosogane, Nobuyuki; Hiratsuka, Hajime; Ichige, Hisashi; Sasajima, Tadayuki; Masaki, Kei; Miya, Naoyuki; Honda, Masao; Iwahashi, Takaaki*; Sasaki, Noboru*; et al.
Fusion Engineering and Design, 58-59, p.331 - 335, 2001/11
Times Cited Count：16 Percentile：71.99(Nuclear Science & Technology)no abstracts in English
Kizu, Kaname; Hiratsuka, Hajime; Ichige, Hisashi; Iwahashi, Takaaki*; Sasajima, Tadayuki; Masaki, Kei; Sasaki, Noboru*; Honda, Masao; Miya, Naoyuki; Hosogane, Nobuyuki
JAERI-Tech 2001-022, 20 Pages, 2001/03
JAERI-Tech-2001-022.pdf:1.34MB
no abstracts in English
Hiratsuka, Hajime; Ichige, Hisashi; Kizu, Kaname; Iwahashi, Takaaki*; Honda, Masao; Kato, Atsushi*
JAERI-Tech 2001-019, 39 Pages, 2001/03
JAERI-Tech-2001-019.pdf:3.55MB
no abstracts in English
Hiratsuka, Hajime; Kizu, Kaname; Ichige, Hisashi; Honda, Masao; Iwahashi, Takaaki*; Sasaki, Noboru*; Miya, Naoyuki; Hosogane, Nobuyuki; Oda, Yasushi*; Yoshida, Kazuto*
Purazuma, Kaku Yugo Gakkai-Shi, 76(11), p.1189 - 1197, 2000/11
no abstracts in English
Shibata, Kaoru*; Takahashi, Nobuaki; Kawakita, Yukinobu; Kamazawa, Kazuya*; Yamada, Takeshi*; Ueno, Hiroki; Shimakura, Hironori; Nakajima, Kenji; Kambara, Wataru; Inamura, Yasuhiro; et al.
no journal, ,
no abstracts in English
Iwahashi, Takaaki; Kambara, Wataru; Ito, Yukihiro; Yoshida, Noboru; Soyama, Kazuhiko; Maruyama, Ryuji; Kajimoto, Ryoichi; Arai, Masatoshi
no journal, ,
4SEASONS is high intensity chopper specrometor for the study of solid state physics such as superconductivity and so on. To archive needed intensity, supermirror guide is selected as a key compornent and the allingment of it is one of key technology. So we install supermirror system in the beamline of 4SEASONS and set up precisery, and measure C-TOF signals. To compare them with calculated one, the allignmet is good enough to archive the needed efficiency of 4SEASONS.
Tanaka, Hiromichi; Yoshida, Noboru; Ito, Yukihiro; Kambara, Wataru; Iwahashi, Takaaki; Katabira, Asahiko*; Goto, Tsuyoshi*; Muroya, Koji*; Sasaki, Taizo*; Machida, Koichi*; et al.
no journal, ,
For the open use of MLF neutron source, robustness (senses including tolerance, stability, acceptable outer affairs) of neutron devices against power noise must be estimated for surely acquition of neutron experimental data. For this purpose, we measure the groundline and power-line shape synclonized with many events, such as crane, chopper, neutron shutter and them on. This data is very usable to solve some accident, such as shutter keeping close. In this presentation, we will show some our solutions.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Nakajima, Kenji; Inamura, Yasuhiro; Takahashi, Nobuaki; Maruyama, Ryuji; Soyama, Kazuhiko; Shibata, Kaoru; Suzuya, Kentaro; et al.
no journal, ,
4SEASONS is one of the neutron chopper spectrometers in J-PARC/MLF. It is intended to provide very high counting rate up to 300 meV neutron energy with medium resolution (
% at 
) to efficiently collect weak inelastic signals from novel spin and lattice dynamics especially in high-
superconductors and related materials. To achieve this goal, the spectrometer equips advanced instrumental design such as an elliptic-shaped converging neutron guide coated with high-
(
-4) supermirror, long-length (2.5 m) 
He PSDs arranged cylindrically inside the vacuum scattering chamber. Furthermore, the spectrometer is ready for multi-incident-energy measurements by the repetition rate multiplication method with a special Fermi chopper, and polarization analysis with He spin filters. 4SEASONS is now under construction and will be ready to use in December 2008. In this paper, we show the design of 4SEASONS and current status of its construction.
Nakajima, Kenji; Kawamura, Seiko; Nakamura, Mitsutaka; Kajimoto, Ryoichi; Inamura, Yasuhiro; Takahashi, Nobuaki; Osakabe, Toyotaka; Wakimoto, Shuichi; Aizawa, Kazuya; Suzuya, Kentaro; et al.
no journal, ,
AMATERAS is a cold-neutron disk-chopper spectrometer newly installed at MLF, J-PARC. The spectrometer has pulse shaping chopper which can cat the source pulse shape as it is required by the experiments. By using newly developed high-speed disk-choppers, the spectrometer realizes both high energy resolution and high intensity with high flexibility in the cold and thermal neutron energy region. The construction of the spectrometer has been completed in spring of 2009. After the commissioning works, now the spectrometer is open to users. In this presentation, we will show the evaluated performances which were obtained in commissioning works.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Takahashi, Nobuaki; Kawamura, Seiko; Maruyama, Ryuji; Soyama, Kazuhiko; et al.
no journal, ,
no abstracts in English
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Nakamura, Mitsutaka; Nakajima, Kenji; Inamura, Yasuhiro; Takahashi, Nobuaki; Maruyama, Ryuji; Soyama, Kazuhiko; Mizuno, Fumio; Shibata, Kaoru; et al.
no journal, ,
no abstracts in English
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Takahashi, Nobuaki; Kawamura, Seiko; Maruyama, Ryuji; Soyama, Kazuhiko; et al.
no journal, ,
no abstracts in English
