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Zeng, Z.*; Zhou, C.*; Zhou, H.*; Han, L.*; Chi, R.*; Li, K.*; Kofu, Maiko; Nakajima, Kenji; Wei, Y.*; Zhang, W.*; et al.
Nature Physics, 20(7), p.1097 - 1102, 2024/07
Nakayama, Shinsuke; Iwamoto, Osamu; Kimura, Atsushi
EPJ Web of Conferences, 294, p.07001_1 - 07001_6, 2024/04
Graphite is a candidate of moderator in innovative nuclear reactors such as molten salt reactors. Scattering of thermal neutrons by the moderator material has a significant impact on the reactor core design. To contribute to the development of innovative nuclear reactors, an evaluation method of thermal neutron scattering law for reactor grade graphite was studied. The inelastic scattering component due to lattice vibration was evaluated based on the phonon density of states computed with first-principles lattice dynamics simulations. The simulations were performed for ideal crystalline graphite. The coherent elastic scattering component due to crystal structure was evaluated based on neutron transmission and scattering experiments recently performed in the J-PARC/MLF facility. In comparison with the neutron transmission experiments, it was found that the quantification of small-angle neutron scattering due to structures larger than crystal, such as pores in graphite, is important. Based on the above methods, thermal neutron scattering law data for reactor-grade graphite at room temperature were evaluated.
Li, J.*; Li, X.*; Zhang, Y.*; Zhu, J.*; Zhao, E.*; Kofu, Maiko; Nakajima, Kenji; Avdeev, M.*; Liu, P.-F.*; Sui, J.*; et al.
Applied Physics Reviews (Internet), 11(1), p.011406_1 - 011406_8, 2024/03
Times Cited Count:0 Percentile:0.00(Physics, Applied)Shinohara, Yuya*; Iwashita, Takuya*; Nakanishi, Masahiro*; Osti, N. C.*; Kofu, Maiko; Nirei, Masami; Dmowski, W.*; Egami, Takeshi*
Journal of Physical Chemistry B, 128(6), p.1544 - 1549, 2024/02
Times Cited Count:0 Percentile:0.00(Chemistry, Physical)Kofu, Maiko; Kawamura, Seiko; Murai, Naoki; Ishii, Rieko*; Hirai, Daigoro*; Arima, Hiroshi*; Funakoshi, Kenichi*
Physical Review Research (Internet), 6(1), p.013006_1 - 013006_9, 2024/01
Inamura, Yasuhiro
JAEA-Testing 2023-002, 80 Pages, 2023/12
"Utsusemi" is a suite of software used to process data obtained from measurements of neutron scattering experiments at the Materials and Life Science Experimental Facility (MLF), J-PARC. To directly obtain the physical quantities which scientists want to get from the data produced by instruments at MLF, many processes are required, such as creating histogram format data, easily visualizing and converting units and correcting intensity adapting the instrument conditions. "Utsusemi" software consists of many software components, many functions for data processing, graphical interface software for executing Utsusemi functions, data visualization applications, and so on. "Utsusemi" has already played an important role in data processing and has been widely employed in MLF beamlines. This document describes how to install the "Utsusemi" software on each operating system to be of help of instrument staff and users who want to process data by themselves. Installation of "Utsusemi" on Windows and macOS requires only general knowledge of working with PC applications according to this document.
Tada, Kenichi
Proceedings of 12th International Conference on Nuclear Criticality Safety (ICNC2023) (Internet), 8 Pages, 2023/10
The number of energy grids of the thermal neutron scattering law data has a large impact on the data size of a cross section file of continuous energy Monte Carlo calculation codes. The optimization of the number of energy grids is an effective way to reduce the data size. This study developed the linearization method of the thermal neutron scattering cross section to optimize the number of energy grids and the linearization function was implemented in the nuclear data processing code FRENDY. The linearization process which is used in the resonance reconstruction and the Doppler broadening was adopted. The criticality benchmarks which use ZrH as the moderator were calculated to estimate the impact of the difference of the energy grids on neutronics calculations. The calculation results indicate that the linearization of the thermal neutron scattering cross section improves the prediction accuracy of neutronics calculations.
Kawaguchi, Maho*; Shiba, Shigeki*; Iwahashi, Daiki*; Okawa, Tsuyoshi*; Gunji, Satoshi; Izawa, Kazuhiko; Suyama, Kenya
Proceedings of 12th International Conference on Nuclear Criticality Safety (ICNC2023) (Internet), 8 Pages, 2023/10
The Nuclear Regulation Authority (NRA) has been working on an experimental approach for evaluating the criticality of fuel debris produced by the Fukushima Daiichi Nuclear Power Plant (FDNP) accident since 2014, collaborating with the Japan Atomic Energy Agency (JAEA). As part of the approach, JAEA has modified the STAtic experiment Critical facilitY (STACY) for critical experiments to evaluate characteriscs of pseudo-fuel debris. As the preliminary analyses, we verified critical characteristics with major nuclear data libraries for the proposed core configuration patterns. The three-dimensional continuous-energy Monte Carlo neutron and photon transport code, SERPENT-V2.2.0 was used with the latest JENDL, JENDL-5. As a result, larger multiplication factors of JENDL-5 across the modified STACY core configuration patterns were evaluated in comparison to the other libraries. And, H scattering and U fission sensitivity coefficients of JENDL-5 were different from those of the other libraries. Comparing among analyses with those libraries, the updated S(, ) of JENDL-5 might affect the result of critical characteristics in the critical analyses for the modified STACY core configuration.
Shamoto, Shinichi; Yamauchi, Hiroki; Iida, Kazuki*; Ikeuchi, Kazuhiko*; Hall, A. E.*; Chen, Y.-S.*; Lee, M. K.*; Balakrishnan, G.*; Chang, L.-J.*
Communications Physics (Internet), 6, p.248_1 - 248_6, 2023/09
Times Cited Count:1 Percentile:52.21(Physics, Multidisciplinary)We show that the local spin correlation order has a spiral structure by neutron scattering measurement of a MnRhSi single crystal. The possible origins of the magnetic cluster formation are discussed in terms of the Lifshitz invariant and the Griffiths phase, and compared with the room-temperature skyrmion phase of CoZnMn and non-Fermi liquid behavior of -Mn.
Yamaguchi, Toshio*; Fukuyama, Nami*; Yoshida, Koji*; Katayama, Yoshinori*; Machida, Shinichi*; Hattori, Takanori
Liquids (Internet), 3(3), p.288 - 302, 2023/09
We report the structure of an aqueous 2 mol/kg MgCl solution at pressures from 0.1 MPa to 4 GPa and temperatures from 300 to 500 K revealed by X-ray and neutron scattering measurements. The scattering data are analyzed by empirical potential structure refinement (EPSR) modeling to derive the pair distribution functions, coordination number distributions, angle distributions, and spatial density functions as a function of pressure and temperature. Mg forms rigid solvation shells extended to the third shell; the first solvation shell of six-fold octahedral coordination with about six water molecules at 0 GPa transforms into about five water molecules and one Cl due to the formation of the contact ion pairs in the GPa pressure range. The Cl solvation shows a substantial pressure dependence; the coordination number of a water oxygen atom around Cl increases from 8 at 0.1 MPa/300 K to 10 at 4 GPa/500 K. The solvent water transforms the tetrahedral network structure at 0.1 MPa/300 K to a densely packed structure in the GPa pressure range; the number of water oxygen atoms around a central water molecule gradually increases from 4.6 at 0.1 MPa/298 K to 8.4 at 4 GPa/500 K.
Ren, Q.*; Gupta, M. K.*; Jin, M.*; Ding, J.*; Wu, J.*; Chen, Z.*; Lin, S.*; Fabelo, O.*; Rodriguez-Velamazan, J. A.*; Kofu, Maiko; et al.
Nature Materials, 22, p.999 - 1006, 2023/05
Times Cited Count:26 Percentile:99.34(Chemistry, Physical)Micheau, C.; Ueda, Yuki; Akutsu, Kazuhiro*; Bourgeois, D.*; Motokawa, Ryuhei
Solvent Extraction and Ion Exchange, 41(2), p.221 - 240, 2023/02
Times Cited Count:1 Percentile:39.98(Chemistry, Multidisciplinary)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
Times Cited Count:4 Percentile:63.40(Multidisciplinary Sciences)Iida, Kazuki*; Kodama, Katsuaki; Inamura, Yasuhiro; Nakamura, Mitsutaka; Chang, L.-J.*; Shamoto, Shinichi
Scientific Reports (Internet), 12, p.20663_1 - 20663_7, 2022/12
Times Cited Count:1 Percentile:24.98(Multidisciplinary Sciences)Spin excitation of an ilmenite FeTiO powder sample is measured by time-of-flight inelastic neutron scattering. The dynamic magnetic pair-density function is obtained from the dynamic magnetic structure factor by the Fourier transformation.
Metoki, Naoto
Hamon, 32(4), p.173 - 176, 2022/11
Nuclear spin polarization and the hyperfine splitting of Nd compounds were studied by means of neutron scattering. We can determine the magnetic moment from the unusual upturn of the antiferromagnetic Bragg intensities due to the interference with the nuclear spin contribution and the magnetic moment.
Yamaguchi, Toshio*; Yoshida, Koji*; Machida, Shinichi*; Hattori, Takanori
Journal of Molecular Liquids, 365, p.120181_1 - 120181_10, 2022/11
Times Cited Count:1 Percentile:13.89(Chemistry, Physical)Neutron scattering measurements were performed on an aqueous 3 mol/kg NaCl solution in DO at temperature and pressure conditions of 0.1 MPa/298K, 1 GPa/298K, 1 GPa/523K, and 4 GPa/523K. The empirical potential structure refinement method was applied to the obtained data to extract the pair correlation function, coordination number distribution, angular distribution (orientation correlation), and spatial density function (3-D structure). From those results, pressure and temperature dependence of solvation and association of ions and solvent-water structure were discussed.
Soda, Minoru*; Kofu, Maiko; Kawamura, Seiko; Asai, Shinichiro*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Furukawa, Hazuki*
Journal of the Physical Society of Japan, 91(9), p.094707_1 - 094707_5, 2022/09
Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)Chen, L.*; Mao, C.*; Chung, J.-H.*; Stone, M. B.*; Kolesnikov, A. I.*; Wang, X.*; Murai, Naoki; Gao, B.*; Delaire, O.*; Dai, P.*
Nature Communications (Internet), 13, p.4037_1 - 4037_7, 2022/07
Times Cited Count:9 Percentile:74.96(Multidisciplinary Sciences)Luo, P.*; Zhai, Y.*; Falus, P.*; Garca Sakai, V.*; Hartl, M.*; Kofu, Maiko; Nakajima, Kenji; Faraone, A.*; Z, Y.*
Nature Communications (Internet), 13, p.2092_1 - 2092_9, 2022/04
Times Cited Count:3 Percentile:54.42(Multidisciplinary Sciences)Rathore, E.*; Juneja, R.*; Sarkar, D.*; Roychowdhury, S.*; Kofu, Maiko; Nakajima, Kenji; Singh, A. K.*; Biswas, K.*
Materials Today Energy (Internet), 24, p.100953_1 - 100953_9, 2022/03
Times Cited Count:14 Percentile:86.18(Chemistry, Physical)