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Su, Y. H.; Lau, W. S.*; Shinohara, Takenao; Parker, J. D.*; Oikawa, Kenichi; Kai, Tetsuya; Tsuchikawa, Yusuke; Hayashida, Hirotoshi*; Matsumoto, Yoshihiro*; Gao, S.*; et al.
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Oikawa, Kenichi; Matsumoto, Yoshihiro*; Sato, Hirotaka*; Watanabe, Kenichi*; Parker, J. D.*; Shinohara, Takenao; Kiyanagi, Yoshiaki*
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Hasemi, Hiroyuki; Tsuchikawa, Yusuke; Kai, Tetsuya; Harada, Masahide; Oikawa, Kenichi; Shinohara, Takenao
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Xu, P. G.; Wang, Y. W.*; Su, Y. H.; Iwamoto, Chihiro*; Wang, H. H.*; Hama, Takayuki*; Shibayama, Yuki; Tsuchikawa, Yusuke; Parker, J. D.*; Kai, Tetsuya; et al.
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Hu, F. F.*; Qin, T. Y.*; Su, Y. H.; Ao, N.*; Zhou, L.*; Xu, P. G.; Parker, J. D.*; Shinohara, Takenao; Wu, S. C.*
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Kurita, Keisuke; Iikura, Hiroshi; Harayama, Isao; Tsuchikawa, Yusuke; Kai, Tetsuya; Shinohara, Takenao; Odaira, Naoya*; Ito, Daisuke*; Saito, Yasushi*; Matsubayashi, Masahito
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Two large neutron experimental facilities are located at the Nuclear Science Research institute site. One is the Japan Proton Accelerator Research Complex (J-PARC). The other is the Japan Research Reactor-3 (JRR-3). Each of them has neutron imaging facilities. In this presentation, we will introduce the performances, updated devices, utilization results and imaging examples of neutron radiography facilities at the JRR-3.
Tsuchikawa, Yusuke; Kai, Tetsuya; Sato, Setsuo*; Oikawa, Kenichi; Shinohara, Takenao
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Neutron resonance imaging is a visualization technique that enables to measure distribution as well as quantitative evaluation of each element present in a sample by neutron resonance peak analysis. In general, neutron imaging is considered to be effective in visualizing relatively light elements. However, since most of the neutron resonances of light elements have energies above keV, it has not been easy to identify light elements. The Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC) is suitable for measurement in the high-energy region because the bunch width of the proton beam that causes spallation is as short as about 100 ns, and the development of detector for light element identification using a fast-response scintillator detector is in progress. The 2012 model lithium-6 time-analyzer neutron detector (LiTA12) in operation at MLF has a sensitive area of 50 mm square and has a spatial resolution of about 0.7 mm. It has 7 Mcps counting rate and is used for neutron measurements in the resonance energy region due to its fast time response. Recently, automated or sequential measurements using LiTA12 have become available. LiTA12 is now as easy to use as other detectors such as uNID and nGEM operating at RADEN/MLF. The system is currently being updated to support imaging with resonance peaks above keV. We are aiming for quantitative imaging of elements with peaks in the tens to hundreds of keV, such as lithium and the commonly used iron, and to this end we are working on elucidating the gamma-ray background and testing the fast response of detectors using plastic scintillators. In this presentation, we will present recent developments of LiTA12 and examples of measurements using the detector.
Fuwa, Yasuhiro; Iwashita, Yoshihisa*
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The magnetic moment of the neutrons is forced due to its interaction with the gradient of the magnetic field, which bends the flight path of the neutrons. This effect makes a sextupole magnet, whose magnetic field gradient is proportional to its distance from the lens axis, acts as a lens for the neutron beam. When the magnitude of the sextupole magnetic field is fixed, the focal length of the lens changes with the wavelength of the neutrons. However, by modulating the magnetic field strength synchronously with the TOF of pulsed neutrons, the focal length of the neutron beam can be controlled to be constant over a wide wavelength range. In this study, we have developed a neutron lens with a magnetic field modulation function and aim to realize imaging using magnification optics. A preliminary experiment performed at HUNS (Hokkaido University Neutron Source) has demonstrated imaging with a magnification factor of 4x for neutrons in the 9 to 13 angstrom wavelength range. The magnification factor and the covered wavelength range can be adjusted by changing the modulation intensity of the magnet and the number of lens units. This optical system can be extended to enable wavelength-dependent imaging that functions as a microscope.