Energy-resolved neutron imaging study of a Japanese sword signed by Bishu Osafune Norimitsu

Oikawa, Kenichi; Matsumoto, Yoshihiro*; Watanabe, Kenichi*; Sato, Hirotaka*; Parker, J. D.*; Shinohara, Takenao; Kiyanagi, Yoshiaki*

Scientific Reports (Internet), 14, p.27990_1 - 27990_11, 2024/11

https://doi.org/10.1038/s41598-024-79436-6

Neutron transmission imaging system with a superconducting kinetic inductance detector

Vu, TheDang*; Shishido, Hiroaki*; Aizawa, Kazuya; Oku, Takayuki; Oikawa, Kenichi; Harada, Masahide; Kojima, Kenji M*; Miyajima, Shigeyuki*; Soyama, Kazuhiko; Koyama, Tomio*; et al.

Journal of Physics; Conference Series, 2776, p.012009_1 - 012009_9, 2024/06

https://doi.org/10.1088/1742-6596/2776/1/012009

Development of an areal density imaging for boron and other elements

Tsuchikawa, Yusuke; Kai, Tetsuya; Abe, Yuta; Oikawa, Kenichi; Parker, J. D.*; Shinohara, Takenao; Sato, Ikken

Journal of Physics; Conference Series, 2605, p.012022_1 - 012022_6, 2023/10

https://doi.org/10.1088/1742-6596/2605/1/012022

We developed a method to obtain the areal density distribution of boron, which has a large neutron cross section, by means of an energy resolved neutron imaging. Commonly in a measurement of elements with very high neutron sensitivity, the quantitative measurement becomes more difficult with the amount of element due to the neutron self-shielding effect. To avoid this effect, an energy-resolved method using known cross section data was attempted, and a quantitative imaging of such elements was demonstrated at the MLF of J-PARC. This presentation introduces a measurement of melted simulated-fuel assemblies obtained in the research of the Fukushima Daiichi Nuclear Power Plant after the severe accident. Energy-dependent neutron transmission rates of the samples were measured by a neutron imaging detector, and were analyzed to obtained the areal density of boron at each position.

Residual stress relaxation by bending fatigue in induction-hardened gear studied by neutron Bragg edge transmission imaging and X-ray diffraction

Su, Y. H.; Oikawa, Kenichi; Shinohara, Takenao; Kai, Tetsuya; Horino, Takashi*; Idohara, Osamu*; Misaka, Yoshitaka*; Tomota, Yo*

International Journal of Fatigue, 174, p.107729_1 - 107729_12, 2023/09

https://doi.org/10.1016/j.ijfatigue.2023.107729

Spatial distribution and preferred orientation of crystalline microstructure of lead-bismuth eutectic

Ito, Daisuke*; Sato, Hirotaka*; Odaira, Naoya*; Saito, Yasushi*; Parker, J. D.*; Shinohara, Takenao; Kai, Tetsuya; Oikawa, Kenichi

Journal of Nuclear Materials, 569, p.153921_1 - 153921_6, 2022/10

https://doi.org/10.1016/j.jnucmat.2022.153921

Determination of site occupancy of boron in 6H-SiC by multiple-wavelength neutron holography

Hayashi, Koichi*; Lederer, M.*; Fukumoto, Yohei*; Goto, Masashi*; Yamamoto, Yuta*; Happo, Naohisa*; Harada, Masahide; Inamura, Yasuhiro; Oikawa, Kenichi; Oyama, Kenji*; et al.

Applied Physics Letters, 120(13), p.132101_1 - 132101_6, 2022/03

https://doi.org/10.1063/5.0080895

Monitoring residual strain relaxation and preferred grain orientation of additively manufactured Inconel 625 by in-situ neutron imaging

Tremsin, A. S.*; Gao, Y.*; Makinde, A.*; Bilheux, H. Z.*; Bilheux, J. C.*; An, K.*; Shinohara, Takenao; Oikawa, Kenichi

Additive Manufacturing, 46, p.102130_1 - 102130_20, 2021/10

https://doi.org/10.1016/j.addma.2021.102130

Practical tests of neutron transmission imaging with a superconducting kinetic-inductance sensor

Vu, TheDang; Shishido, Hiroaki*; Aizawa, Kazuya; Kojima, Kenji M*; Koyama, Tomio*; Oikawa, Kenichi; Harada, Masahide; Oku, Takayuki; Soyama, Kazuhiko; Miyajima, Shigeyuki*; et al.

Nuclear Instruments and Methods in Physics Research A, 1006, p.165411_1 - 165411_8, 2021/08

AA2020-0482.pdf:3.12MB

https://doi.org/10.1016/j.nima.2021.165411

Experimental characterization of high-energy component in extracted pulsed neutrons at the J-PARC spallation neutron source

Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Takada, Hiroshi; Ikeda, Yujiro

Nuclear Instruments and Methods in Physics Research A, 1000, p.165252_1 - 165252_8, 2021/06

https://doi.org/10.1016/j.nima.2021.165252

This study explores high-energy neutron components of the extracted neutron beam at J-PARC pulsed neutron source using the foil activation method with threshold reactions. Foils of aluminum, gold, bismuth, niobium, and thulium were used to cover the neutron energy range from 0.3 MeV to 79.4 MeV. The experiment was performed using neutron beams of BL10 (NOBORU). The foils were irradiated by a neutron beam at 13.4 m from the moderator. To characterize high-energy neutron fields for irradiation applications, reaction rates in three different configurations with and without BC slit and Pb filter were examined. To compare the experiments with calculations given for the user, reaction rates for corresponding reactions were calculated by the PHITS code with the JENDL-3.2 and the JENDL dosimetry file. Although there was a systematic tendency in C/E (Calculation/Experiment) ratios for different threshold energies, which C/E ratio decreased as threshold energy increased up to 100 MeV, and all C/E ratios were in the range of 1.00.2. This indicated that high-energy neutron calculations were adequate for the analysis of experimental data for NOBORU users.

Feasibility study of PGAA for boride identification in simulated melted core materials

Tsuchikawa, Yusuke; Abe, Yuta; Oishi, Yuji*; Kai, Tetsuya; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Kimura, Atsushi; Nakamura, Shoji; Harada, Masahide; et al.

JPS Conference Proceedings (Internet), 33, p.011074_1 - 011074_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011074

In the decommissioning of the Fukushima-Daiichi (1F) Nuclear Power Plant, it is essential to understand characteristics of the melted core materials. The estimation of boride in the real debris is of great importance to develop safe debris removal plans. Hence, it is required to investigate the amount of boron in the melted core materials with nondestructive methods. Prompt gamma-ray activation analysis (PGAA) is one of the useful techniques to determine the amount of borides by means of the 478 keV prompt gamma-ray from neutron absorption reaction of boron. Moreover, it is well known that the width of the 478 keV gamma-ray peak is typically broadened due to the Doppler effect. The degree of the broadening is affected by coexisting materials, and can be recognized by the width of the prompt gamma-ray peak. As a feasibility study, the prompt gamma-ray from boride samples were measured using the ANNRI, NOBORU, and RADEN beamlines at the Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Complex (J-PARC).