Unveiling the local effects of PTL passivation in PEM Electrolyzers through gas and current mapping using operando neutron radiography and polarized neutron imaging

Karimi, V.*; Qvistgaard, C. H.*; Schmidt, S.*; Wolfertz, A.*; Parker, J. D.*; Kai, Tetsuya; Hayashida, Hirotoshi*; Shinohara, Takenao; Angelis, S. D.*; Tengattini, A.*; et al.

ACS Applied Materials & Interfaces, 17(36), p.50742 - 50752, 2025/08

https://doi.org/10.1021/acsami.5c11706

Neutron resonance absorption imaging fully utilizing neutron energies from 1 eV to 100 keV

Tsuchikawa, Yusuke; Kai, Tetsuya; Parker, J.*; Matsumoto, Yoshihiro*; Shinohara, Takenao

Scientific Reports (Internet), 15, p.7687_1 - 7687_8, 2025/03

https://doi.org/10.1038/s41598-025-92174-7

A neutron resonance absorption imaging technique to visualize two-dimensional distributions with element discrimination has been developed at the Materials and Life Science Experimental Facility of the Japan Proton Accelerator Research Complex. We measured neutron transmission spectra from 1 eV to 100 keV while rotating a sample containing iron, zirconium, nickel, molybdenum, and aluminum rods. The distributions of hafnium (impurity of zirconium) and molybdenum were clearly obtained by a straightforward analysis using the most prominent resonances. Then an analysis using multiple resonances of each element simultaneously was performed finding that the accuracy of elemental identification was improved, and iron and nickel distributions became clearer. However, these analysis methods sometimes have difficulties in the case of overlapping materials since a resonance shape can be deteriorated by those of other materials. Such an example was demonstrated with the case of iron and nickel. To overcome the issue and aiming for further improvement, we proposed a method to fit the transmission spectrum in a wide range assuming the existence of possible elements, successfully visualizing both the distributions of the sample metals and those of hafnium and manganese (impurities of zirconium and iron). The newly introduced analysis technique will contribute to the establishment of a standard analytical procedure for general users of the facility.

Manuals for resonance analysis code for neutron IMaging "RAIM"

Hasemi, Hiroyuki; Kai, Tetsuya

JAEA-Testing 2024-001, 39 Pages, 2024/08

JAEA-Testing-2024-001.pdf:1.4MB

RAIM is an analysis code that analyzes resonance absorption spectra measured at pulsed neutron sources such as the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC) to obtain information on nuclear densities and temperatures. By calculating the convolution of the pulse functions of neutron beam and the resonance capture function that is based on the nuclear cross section data, RAIM reproduces the resonance absorption spectrum measured by a pulsed neutron source. Then, RAIM determines the density and temperature of specific nuclides in a sample by performing spectral fitting on the resonance absorption spectrum data. In addition, RAIM is developed to facilitate the analysis of resonance imaging data by minimizing the number of parameters for calculation setup and by providing scripts for processing many resonance absorption spectra measured by a two-dimensional detector at once. This manual explains how to install RAIM on a computer and how to simulate resonance absorption spectra and fit them to measured data.

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.

Introduction to Neutron Radiography Facilities at the Japan Research Reactor-3

Kurita, Keisuke; Iikura, Hiroshi; Tsuchikawa, Yusuke; Kai, Tetsuya; Shinohara, Takenao; Odaira, Naoya*; Ito, Daisuke*; Saito, Yasushi*; Matsubayashi, Masahito

Journal of Physics; Conference Series, 2605, p.012005_1 - 012005_6, 2023/10

https://doi.org/10.1088/1742-6596/2605/1/012005

The Japan Research Ractor-3 (JRR-3) is operation resumed on February 26, 2021, and the shared use was also restarted in July, 2021. With the resumption of JRR-3 operation, two imaging facilities called TNRF and CNRF have also resumed their utilization. In this presentation, we report the details of these two neutron facilities.

Damage accumulation and recovery involving vacancy-type defects enhanced by hydrogen in tempered martensitic steel showing quasi-cleavage fracture

Saito, Kei*; Hirade, Tetsuya; Takai, Kenichi*

Key Engineering Materials, 967, p.11 - 16, 2023/07

https://doi.org/10.4028/p-kfgx2c

Hydrogen-enhanced strain-induced vacancy, one of the defects associated with promising hydrogen embrittlement mechanisms, was validated for tempered martensitic steel showing quasi-cleavage fracture with a tensile strength of 1500 MPa level by slow strain rate tensile test in-situ electrochemical hydrogen charging. The effect of newly formed vacancy-type defects on mechanical properties of tempered martensitic steel was also studied. Combined use of low-temperature thermal desorption spectroscopy (L-TDS) and the tensile test revealed the following three things: (i) hydrogen enhanced the accumulation of vacancy-type defects with plastic straining, (ii) accumulated vacancy-type defects deteriorated the ductility of the tempered martensitic steel after hydrogen release, and (iii) aging in the range from 50C to 150C after applying given plastic strain with hydrogen charging decreased the amount of newly formed vacancy-type defects, and then resulted in the recovery of the ductility.

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

Tracer diffusion coefficients measurements on LaPO-dispersed LATP by means of neutron radiography

Song, F.*; Chen, H.*; Hayashida, Hirotoshi*; Kai, Tetsuya; Shinohara, Takenao; Yabutsuka, Takeshi*; Yao, Takeshi*; Takai, Shigeomi*

Solid State Ionics, 377, p.115873_1 - 115873_6, 2022/04

https://doi.org/10.1016/j.ssi.2022.115873

A Multi-technique tomography-based approach for non-invasive characterization of additive manufacturing components in view of vacuum/UHV applications; Preliminary results

Grazzi, F.*; Cialdai, C.*; Manetti, M.*; Massi, M.*; Morigi, M. P.*; Bettuzzi, M.*; Brancaccio, R.*; Albertin, F.*; Shinohara, Takenao; Kai, Tetsuya; et al.

Rendiconti Lincei. Scienze Fisiche e Naturali, 32(3), p.463 - 477, 2021/09

https://doi.org/10.1007/s12210-021-00994-2

Observation of Eu adsorption band in the CMPO/SiO-P column by neutron resonance absorption imaging

Miyazaki, Yasunori; Watanabe, So; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori; Kai, Tetsuya; Parker, J. D.*

JPS Conference Proceedings (Internet), 33, p.011073_1 - 011073_7, 2021/03

https://doi.org/10.7566/JPSCP.33.011073

Neutron resonance absorption imaging was adapted to observe the Eu band adsorbed in the CMPO/SiO-P column for minor actinide recovery by extraction chromatography. Several wet columns were prepared by either light water or heavy water and compared with the dry column to evaluate the neutron transmission. The neutron transmission spectra showed that 45% was transmitted through the dry column while 20% and 40% were transmitted through the wet columns of light water and heavy water, respectively. The results indicated that heavy water is more applicable than light water to observe the Eu adsorption band in the CMPO/SiO-P column.