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Journal Articles

Recent progress on practical materials study by Bragg edge imaging at J-PARC

Oikawa, Kenichi; Su, Y.; Kiyanagi, Ryoji; Kawasaki, Takuro; Shinohara, Takenao; Kai, Tetsuya; Hiroi, Kosuke; Harjo, S.; Parker, J. D.*; Matsumoto, Yoshihiro*; et al.

Physica B; Condensed Matter, 551, p.436 - 442, 2018/12

 Percentile:100(Physics, Condensed Matter)

Journal Articles

Study of the magnetization distribution in a grain-oriented magnetic steel using pulsed polarized neutron imaging

Hiroi, Kosuke; Shinohara, Takenao; Hayashida, Hirotoshi*; Parker, J. D.*; Su, Y.; Oikawa, Kenichi; Kai, Tetsuya; Kiyanagi, Yoshiaki*

Physica B; Condensed Matter, 551, p.146 - 151, 2018/12

 Times Cited Count:1 Percentile:100(Physics, Condensed Matter)

Journal Articles

Characteristics of the 2012 model lithium-6 time-analyzer neutron detector (LiTA12) system as a high efficiency detector for resonance absorption imaging

Kai, Tetsuya; Sato, Setsuo*; Hiroi, Kosuke; Su, Y.; Segawa, Mariko; Parker, J. D.*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Shinohara, Takenao; Oikawa, Kenichi; et al.

Physica B; Condensed Matter, 551, p.496 - 500, 2018/12

 Percentile:100(Physics, Condensed Matter)

Journal Articles

Spatial resolution test targets made of gadolinium and gold for conventional and resonance neutron imaging

Segawa, Mariko; Oikawa, Kenichi; Kai, Tetsuya; Shinohara, Takenao; Hayashida, Hirotoshi*; Matsumoto, Yoshihiro*; Parker, J. D.*; Nakatani, Takeshi; Hiroi, Kosuke; Su, Y.; et al.

JPS Conference Proceedings (Internet), 22, p.011028_1 - 011028_8, 2018/11

Journal Articles

Development of a polarization analysis method for visualization of the magnetic field distribution in a small electric transformer using pulsed polarized neutron imaging

Hiroi, Kosuke; Shinohara, Takenao; Hayashida, Hirotoshi*; Parker, J. D.*; Oikawa, Kenichi; Su, Y.; Kai, Tetsuya; Kiyanagi, Yoshiaki*

JPS Conference Proceedings (Internet), 22, p.011030_1 - 011030_7, 2018/11

Journal Articles

Imaging measurement of neutron attenuation by small-angle neutron scattering using soller collimator

Oba, Yojiro; Shinohara, Takenao; Sato, Hirotaka*; Onodera, Yohei*; Hiroi, Kosuke; Su, Y.; Sugiyama, Masaaki*

Journal of the Physical Society of Japan, 87(9), p.094004_1 - 094004_5, 2018/09

 Percentile:100(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

Visualization technique with the energy-resolved neutron imaging system, RADEN

Kai, Tetsuya; Shinohara, Takenao; Hiroi, Kosuke; Su, Y.; Oikawa, Kenichi

Hihakai Kensa, 67(5), p.209 - 216, 2018/05

no abstracts in English

Journal Articles

Magnetic Bragg dip and Bragg edge in neutron transmission spectra of typical spin superstructures

Mamiya, Hiroaki*; Oba, Yojiro; Terada, Noriki*; Watanabe, Norimichi*; Hiroi, Kosuke; Shinohara, Takenao; Oikawa, Kenichi

Scientific Reports (Internet), 7(1), p.15516_1 - 15516_8, 2017/11

 Times Cited Count:1 Percentile:81.49(Multidisciplinary Sciences)

no abstracts in English

Journal Articles

Maximizing $$T_c$$ by tuning nematicity and magnetism in FeSe$$_{1-x}$$S$$_x$$ superconductors

Matsuura, Kohei*; Mizukami, Yuta*; Arai, Yuki*; Sugimura, Yuichi*; Maejima, Naoyuki*; Machida, Akihiko*; Watanuki, Tetsu*; Fukuda, Tatsuo; Yajima, Takeshi*; Hiroi, Zenji*; et al.

Nature Communications (Internet), 8, p.1143_1 - 1143_6, 2017/10

 Times Cited Count:16 Percentile:13.58(Multidisciplinary Sciences)

Journal Articles

Reliability estimation of neutron resonance thermometry using tantalum and tungsten

Kai, Tetsuya; Hiroi, Kosuke; Su, Y.; Shinohara, Takenao; Parker, J. D.*; Matsumoto, Yoshihiro*; Hayashida, Hirotoshi*; Segawa, Mariko; Nakatani, Takeshi; Oikawa, Kenichi; et al.

Physics Procedia, 88, p.306 - 313, 2017/06

 Times Cited Count:1 Percentile:8.64

Journal Articles

Time-of-flight neutron transmission imaging of martensite transformation in bent plates of a Fe-25Ni-0.4C alloy

Su, Y.; Oikawa, Kenichi; Shinohara, Takenao; Kai, Tetsuya; Hiroi, Kosuke; Harjo, S.; Kawasaki, Takuro; Gong, W.; Zhang, S. Y.*; Parker, J. D.*; et al.

Physics Procedia, 88, p.42 - 49, 2017/06

 Times Cited Count:1 Percentile:14.69

Journal Articles

A Comparative study of the crystallite size and the dislocation density of bent steel plates using Bragg-edge transmission imaging, TOF neutron diffraction and EBSD

Oikawa, Kenichi; Su, Y.; Tomota, Yo*; Kawasaki, Takuro; Shinohara, Takenao; Kai, Tetsuya; Hiroi, Kosuke; Zhang, S.*; Parker, J. D.*; Sato, Hirotaka*; et al.

Physics Procedia, 88, p.34 - 41, 2017/00

 Times Cited Count:1 Percentile:14.69

Time of flight Bragg edge transmission (BET) imaging was adopted to the plastically bent plates of a ferritic steel and a duplex stainless steel, and the obtained results were validated using neutron diffraction method and electron backscatter diffraction (EBSD) observations. The BET imaging results of texture distribution and phase volume fractions showed good agreements with those obtained by neutron diffraction and EBSD. The crystallite size evaluation using extinction correction was succeeded by the RITS code where Sabine's primary extinction function was applied, however, the crystallite size was not obtained by the Rietveld refinement where the same function was used for the evaluation. In this study, we comparatively reinvestigate the crystallite size and the dislocation density of the plastically bent steel plates by the use of Pawley analysis on the diffraction data and grain analysis on EBSD data.

JAEA Reports

Optimization of the magnetic field environment in the polarization analysis system of BL22 "RADEN" at J-PARC/MLF (Contract research)

Hiroi, Kosuke; Shinohara, Takenao; Hayashida, Hirotoshi*; Su, Y.; Kai, Tetsuya; Oikawa, Kenichi

JAEA-Technology 2016-021, 14 Pages, 2016/10

JAEA-Technology-2016-021.pdf:16.4MB

Energy resolved neutron imaging techniques have been developed at BL22 "RADEN" installed in the Materials and Life Science Experimental Facility (MLF) of J-PARC. A polarized neutron imaging technique attracts much attention as a magnetic imaging method that enables to obtain a quantitative magnetic field distribution in an industrial product under driving state. At RADEN, a polarization analysis apparatus for polarized neutron imaging experiments has been prepared, but its performance was not fully achieved due to imperfectness of the field connection between devices. To improve the performance of polarization analysis system at RADEN, we performed magnetic field simulation of this system, and optimized the magnetic field environment by evaluating the magnetic field connection. After the optimization, we rearranged devices of the system, and confirmed that uniform polarization distribution could be obtained within 4$$times$$4 cm$$^{2}$$ field of view.

Journal Articles

Time-of-flight neutron Bragg-edge transmission imaging of microstructures in bent steel plates

Su, Y.; Oikawa, Kenichi; Harjo, S.; Shinohara, Takenao; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke; Zhang, S.*; Parker, J. D.*; Sato, Hirotaka*; et al.

Materials Science and Engineering A, 675, p.19 - 31, 2016/10

 Times Cited Count:8 Percentile:28.67(Nanoscience & Nanotechnology)

Journal Articles

Development status of the NMR system for the polarized $$^{3}$$He Neutron Spin Filter (NSF) in the MLF at J-PARC

Sakai, Kenji; Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Hiroi, Kosuke; Ino, Takashi*; Oyama, Kenji*; Okawara, Manabu*; Kakurai, Kazuhisa; Shinohara, Takenao; et al.

JPS Conference Proceedings (Internet), 8, p.036015_1 - 036015_6, 2015/09

The polarized $$^{3}$$He filter, which polarizes neutrons due to a large neutron absorption cross section of $$^{3}$$He with strong spin selectivity, becomes a convenient neutron spin filter (NSF) because it is operated immediately after its installation in beam lines without any neutron beam adjustments. For realizing such the NSF, a nuclear magnetic resonance (NMR) system is indispensable for monitoring $$^{3}$$He nuclear spin polarization ${it P}$ of the NSF. We have developed the flexible NMR system based on adiabatic fast passage (AFP) and pulse NMR methods by using their complementary features. In comparing with the values of ${it P}$ obtained by neutron transmission measurement at the beam line 10 of the J-PARC, we measured the correlations between the AFP and pulse NMR signals as changing condition of temperature, amplitude and applying period of the radio frequency field for the pulse NMR, and so on. As the results, we confirmed that our system would function enough as the ${it P}$ monitor.

Oral presentation

Development of compact laser optics for an in-situ spin-exchange optical pumping $$^3$$He neutron spin filter

Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Shinohara, Takenao; Sakaguchi, Yoshifumi*; Ino, Takashi*; Oyama, Kenji*; Chang, L.-J.*; et al.

no journal, , 

We have been developing a $$^3$$He neutron spin filter (NSF) for the efficient utilization of pulsed neutrons, since it can polarize neutrons effectively in a wide energy range. The $$^3$$He NSF is effective even for neutrons with energy higher than several-tens-meV, so that it will be useful for the study of high-energy magnetic excitation. Since the $$^3$$He NSF can also cover a large solid angle and polarize neutrons without deflecting them from their original course, it is suitable for the analyzer for SANS instruments and reflectometers. In addition, the $$^3$$He NSF will be a key device in the application of recently developed magnetic field imaging technique by using polarized pulsed neutrons. In order to apply the $$^3$$He NSF to experiments at a pulsed neutron experimental facility such as the J-PARC, it is important to make the system stable and easy to setup and operate, because the system is located inside a radiation shield for high energy $$gamma$$ ray and neutrons. In this study, we have developed compact laser optics with a volume holographic grating element for a spin-exchange optical pumping (SEOP) system, and composed an in-situ SEOP $$^3$$He NSF.

Oral presentation

Development of AC magnetic field imaging technique using polarized pulsed neutrons

Hiroi, Kosuke; Shinohara, Takenao; Hayashida, Hirotoshi*; Oikawa, Kenichi; Harada, Masahide; Kai, Tetsuya; Arai, Masatoshi

no journal, , 

We have been developing a quantitative magnetic field imaging technique at J-PARC. Applying this method to observation of a magnetic field in industrial products, it is necessary to extend this technique to an AC magnetic field driving at a frequency of commercial power supply. In this study, we tried to visualize an AC magnetic field quantitatively. The AC magnetic field was produced by applying an AC electric current to a small solenoid coil. By recording a start time of the AC field, we calculated a phase of the field in which polarized neutron traverse and obtained polarization distribution images at each phase and its wavelength dependence. We analyzed the wavelength dependence of polarization and estimated the field strength at each phase. As a result, sinusoidal waveform of the AC field was successfully reproduced and its strength was almost corresponded to the value that expected from applied AC current.

Oral presentation

Current status and perspectives in the development of an in-situ spin-exchange optical pumping $$^3$$He neutron spin filter at J-PARC

Oku, Takayuki; Kira, Hiroshi*; Hayashida, Hirotoshi*; Sakai, Kenji; Hiroi, Kosuke; Shinohara, Takenao; Sakaguchi, Yoshifumi*; Ino, Takashi*; Oyama, Kenji*; Nakamura, Mitsutaka; et al.

no journal, , 

We have been developing a $$^{3}$$He neutron spin filter (NSF) for the efficient utilization of pulsed neutrons, since it can polarize neutrons effectively in a wide energy range. The $$^{3}$$He NSF is effective even for neutrons with energy higher than several-tens-meV, so that it will be useful for the study of high-energy magnetic excitation. Since the $$^{3}$$He NSF can also cover a large solid angle and polarize neutrons without deflecting them from their original course, it is suitable for the analyzer for SANS instruments and reflectometers. In addition, the $$^{3}$$He NSF will be a key device in the application of recently developed magnetic field imaging technique by using polarized pulsed neutrons. In order to apply the $$^{3}$$He NSF to such experiments at a pulsed neutron experimental facility such as the J-PARC, we have developed compact laser optics with a volume holographic grating (VHG) element for a spin-exchange optical pumping (SEOP) system, and composed an in-situ SEOP $$^{3}$$He NSF. Current status in the development and application of the in-situ SEOP $$^{3}$$He NSF at J-PARC will be presented, and perspectives will be discussed.

Oral presentation

Magnetic shield design of in-situ SEOP polarized $$^{3}$$He neutron spin filter for high magnetic field sample environment accessories at J-PARC

Kira, Hiroshi*; Hayashida, Hirotoshi*; Oku, Takayuki; Sakai, Kenji; Hiroi, Kosuke; Ino, Takashi*; Oyama, Kenji*; Okawara, Manabu*; Kakurai, Kazuhisa; Suzuki, Junichi*; et al.

no journal, , 

Oral presentation

Development of compact laser optics for an in-situ spin-exchange optical pumping $$^3$$He neutron spin filter

Oku, Takayuki; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Shinohara, Takenao; Sakaguchi, Yoshifumi*; Ino, Takashi*; Oyama, Kenji*; Chang, L.-J.*; et al.

no journal, , 

The $$^3$$He NSF is effective even for neutrons with energy higher than several-tens-meV, so that it will be useful for the study of high-energy magnetic excitation. Since the $$^3$$He NSF can also cover a large solid angle and polarize neutrons without deflecting them from their original course, it is suitable for the analyzer for SANS instruments and reflectometers. In order to apply the $$^3$$He NSF to experiments at a pulsed neutron experimental facility such as the J-PARC, it is important to make the system stable and easy to setup and operate, because the system is located inside a radiation shield for high energy $$gamma$$ ray and neutrons. In this study, we have developed compact laser optics with a volume holographic grating (VHG) element for a spin-exchange optical pumping (SEOP) system, and composed an in-situ SEOP $$^3$$He NSF. The design and performance of the in-situ SEOP $$^3$$He NSF will be then presented, and its possible application will be discussed.

74 (Records 1-20 displayed on this page)