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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：4.76(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.
Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.
Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05
The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading 
He cryostat, a bottom-loading 
He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.
Kajimoto, Ryoichi; Ishikado, Motoyuki*; Kira, Hiroshi*; Kaneko, Koji; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Murai, Naoki; et al.
Physica B; Condensed Matter, 556, p.26 - 30, 2019/03
Times Cited Count：2 Percentile：10.61(Physics, Condensed Matter)Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya*; Kofu, Maiko; Kawakita, Yukinobu; Inamura, Yasuhiro; Kambara, Wataru*; Aoyama, Kazuhiro*; Wakai, Daisuke*; Harada, Masahide; et al.
Journal of Physics; Conference Series, 1021(1), p.012031_1 - 012031_5, 2018/06
Times Cited Count：5 Percentile：94.52(Nuclear Science & Technology)Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; et al.
JAEA-Conf 2015-002, p.319 - 329, 2016/02
Nakamura, Mitsutaka; Kawakita, Yukinobu; Kambara, Wataru; Aoyama, Kazuhiro; Kajimoto, Ryoichi; Nakajima, Kenji; Kawamura, Seiko; Ikeuchi, Kazuhiko*; Kikuchi, Tatsuya; Inamura, Yasuhiro; et al.
JPS Conference Proceedings (Internet), 8, p.036011_1 - 036011_6, 2015/09
The needs for inelastic neutron scattering experiments under the special sample environment such as strong magnetic field and high temperature are recently increasing. However, the unwanted scatterings originating from these devices affect the detection of weak inelastic signals. In order to overcome this problem we have developed an oscillating radial collimator specialized for the chopper spectrometer at Materials and Life Science Experimental Facility (MLF) in J-PARC. In this study, we will report the performances of newly-developed oscillating radial collimators both for 4SEASONS and AMATERAS.
Oki, Koichi; Aoyama, Yasuhiro; Sukegawa, Yasuhiro*; Suzuki, Satoshi*; Sagawa, Hiroshi*; Hideo, Doi,*; Endo, Yasumi*
Waste Management 2005 Proceeding, CD-ROM, 8p., 8 Pages, 2005/03
We developed as a new technique to remove the influence of distance between radionuclides and detectors. We named the technique "the Facing Couple Method (FCM)". Partcality inspection which uses uranium source was parformed.Furthermore, the application possibility to a system was confirmed.
Sukegawa, Yasuhiro*; Suzuki, Satoshi*; Aoyama, Yasuhiro; Oki, Koichi
JNC TN8410 2004-012, 126 Pages, 2004/11
JNC-TN8410-2004-012.pdf:6.06MB
This report summarizes the system design carried out in order for the passive gamma method to estimate the uranium content in container waste among uanium wastes, construction of an analysis evaluation code, simulation, performance tests.
Oki, Koichi; Aoyama, Yasuhiro; Sukegawa, Yasuhiro*; Suzuki, Satoshi*; Sagawa, Hiroshi*; Hideo, Doi,*; Endo, Yasumi*
Saikuru Kiko Giho, (25), p.57 - 68, 2004/00
The system which measures and evaluates the quantity of uranium in the uranium contaminated waste in a large-sized container by NDA technology was manufactured.Practicality inspection which uses an uranium source was performed. Furthermore, the application possibility to a system was confirmed.
Nakamura, Mitsutaka; Kawakita, Yukinobu; Kambara, Wataru; Aoyama, Kazuhiro; Yamauchi, Yasuhiro; Kajimoto, Ryoichi; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Inamura, Yasuhiro; Nakajima, Kenji; et al.
no journal, ,
In recent years, the need for neutron inelastic scattering experiments in special environments under the strong magnetic field and the high temperature is increasing. On the other hand, there is a problem that the unnecessary scattering originating from the sample environment devices affects the detection of weak inelastic signals. To solve this problem, we have been developing the radial collimator for chopper spectrometer at J-PARC. In this talk, we plan to introduce the performance evaluation results of our radial collimator.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Suzuki, Junichi*; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; et al.
no journal, ,
no abstracts in English
Nakamura, Mitsutaka; Kawakita, Yukinobu; Kambara, Wataru; Yamauchi, Yasuhiro; Aoyama, Kazuhiro; Kajimoto, Ryoichi; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Inamura, Yasuhiro; Nakajima, Kenji; et al.
no journal, ,
Recently, there is a growing need for neutron inelastic scattering experiments under special sample environments such as strong magnetic field and high temperatures. However the unwanted scattering originating from the sample environment equipment adversely affect the detection of weak inelastic signal. In order to overcome these difficulties, we have developed the radial collimators for chopper spectrometers at J-PARC. In this report we will show the results of performance evaluation tests for radial collimators.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Suzuki, Junichi*; Nakajima, Kenji; Kawamura, Seiko; et al.
no journal, ,
no abstracts in English
Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Kawakita, Yukinobu; Inamura, Yasuhiro; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Tanaka, Hiromichi; Iwahashi, Takaaki; Kambara, Wataru; et al.
no journal, ,
AMATERAS is a cold-neutron multi disk-chopper spectrometer at J-PARC. AMATERAS is designed to realize high intensity and fine and flexible energy resolution measurements in quasielastic and inelastic neutron scattering experiments from cold to thermal neutron energy region. AMATERAS had the first neutron beam in May 2009. After then, experiments of more than 70 proposals (including 17 in house projects proposals) have been carried out and results were distributed as 15 scientific papers and more than 100 presentations at domestic and international scientific meetings by users.
Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Kawakita, Yukinobu; Inamura, Yasuhiro; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Soyama, Kazuhiko; Harada, Masahide; Oikawa, Kenichi; et al.
no journal, ,
Kambara, Wataru; Aoyama, Kazuhiro; Yamauchi, Yasuhiro; Iwahashi, Takaaki; Ono, Shino; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Shibata, Kaoru; Nakajima, Kenji; Kawamura, Seiko; et al.
no journal, ,
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Ishikado, Motoyuki*; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; et al.
no journal, ,
no abstracts in English
Nakajima, Kenji; Kawamura, Seiko; Kikuchi, Tatsuya; Inamura, Yasuhiro; Kawakita, Yukinobu; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Soyama, Kazuhiko; Arai, Masatoshi; Aoyama, Kazuhiro; et al.
no journal, ,
no abstracts in English
Nakamura, Mitsutaka; Kajimoto, Ryoichi; Inamura, Yasuhiro; Aoyama, Kazuhiro; Kambara, Wataru*; Kawakami, Kazuhiro; Kubo, Naoya; Kamazawa, Kazuya*; Ikeuchi, Kazuhiko*; Iida, Kazuki*; et al.
no journal, ,
We have developed a newly designed Fermi chopper for MLF/BL01 4SEASONS, and has been open for users since March 2015. It was found that the gain factor achieved in the low-energy region is more than 10, thus, we succeeded to greatly improve the measurement efficiency of 4SEASONS. In this presentation we will show the details of both specification and design for a newly-developed Fermi chopper.
Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Nakajima, Kenji; Kawamura, Seiko; Nakatani, Takeshi; Kambara, Wataru*; Kubo, Naoya; Aoyama, Kazuhiro; Kawakami, Kazuhiro; et al.
no journal, ,
no abstracts in English
