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Soyama, Kazuhiko; Hayashida, Hirotoshi*; Maruyama, Ryuji; Yamazaki, Dai; Goto, Yoshiki*; Kobayashi, Yuki*; Arakawa, Shohei*; Yamamoto, Yugo*; Suba, Kenta*; Yamamura, Kazuya*
JAEA-Research 2024-006, 15 Pages, 2024/10
JAEA-Research-2024-006.pdf:1.51MB
A neutron optics design has been conducted for a neutron magnetic microscope that utilize a Wolter type I multilayer supermirror for the purpose of magnetic fields imaging in magnetic materials. Ray trace simulation was performed for a magnifying imaging optical system with a magnification rate of 12.5 times. Based on classical model of Lamor precession, depolarization due to magnetic domains was simulated, and the effect of slope errors on the Wolter mirror created by the replica method on the spatial resolution of the microscope was investigated. As a result, reference data about the shape error required to obtain spatial resolution on the order of micrometers was obtained.
Yamazaki, Dai; Maruyama, Ryuji; Aoki, Hiroyuki; Hanashima, Takayasu*; Akutsu-Suyama, Kazuhiro*; Miyata, Noboru*; Soyama, Kazuhiko
Quantum Beam Science (Internet), 9(2), p.20_1 - 20_12, 2024/06
Yamada, Kazuo*; Hokora, Hideyuki*; Maruyama, Ippei*; Aihara, Haruka; Tomita, Sayuri*; Tojo, Yasumasa*; Shibuya, Kazutoshi*; Hosokawa, Yoshifumi*; Igarashi, Go*; Koma, Yoshikazu
Proceedings of Waste Management Symposia 2024 (WM2024) (Internet), 7 Pages, 2024/03
Maruyama, Yu; Sugiyama, Tomoyuki*; Shimada, Asako; Lind, T.*; Bentaib, A.*; Sogalla, M.*; Pellegrini, M.*; Albright, L.*; Clayton, D.*
Proceedings of 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20) (Internet), p.4782 - 4795, 2023/08
Yamada, Kazuo*; Tojo, Yasumasa*; Aihara, Haruka; Tomita, Sayuri*; Hokora, Hideyuki*; Shibuya, Kazutoshi*; Koma, Yoshikazu; Igarashi, Go*; Hosokawa, Yoshifumi*; Maruyama, Ippei*
Proceedings of Waste Management Symposia 2023 (WM2023) (Internet), 12 Pages, 2023/02
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Lind, T.*; Herranz, L. E.*; Sonnenkalb, M.*; Maruyama, Yu
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 15 Pages, 2022/03
Gupta, S.*; Herranz, L. E.*; Lebel, L. S.*; Sonnenkalb, M.*; Pellegrini, M.*; Marchetto, C.*; Maruyama, Yu; Dehbi, A.*; Suckow, D.*; K
rkel, T.*
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 16 Pages, 2022/03
Maruyama, Ryuji; Yamazaki, Dai; Aoki, Hiroyuki; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Soyama, Kazuhiko; Bigault, T.*; Saerbeck, T.*; Courtois, P.*
Journal of Applied Physics, 130(8), p.083904_1 - 083904_10, 2021/08
Times Cited Count：3 Percentile：17.60(Physics, Applied)Yonomoto, Taisuke; Nakashima, Hiroshi*; Sono, Hiroki; Kishimoto, Katsumi; Izawa, Kazuhiko; Kinase, Masami; Osa, Akihiko; Ogawa, Kazuhiko; Horiguchi, Hironori; Inoi, Hiroyuki; et al.
JAEA-Review 2020-056, 51 Pages, 2021/03
JAEA-Review-2020-056.pdf:3.26MB
A group named as "The group for investigation of reasonable safety assurance based on graded approach", which consists of about 10 staffs from Sector of Nuclear Science Research, Safety and Nuclear Security Administration Department, departments for management of nuclear facility, Sector of Nuclear Safety Research and Emergency Preparedness, aims to realize effective graded approach (GA) about management of facilities and regulatory compliance of JAEA. The group started its activities in September, 2019 and has had discussions through 10 meetings and email communications. In the meetings, basic ideas of GA, status of compliance with new regulatory standards at each facility, new inspection system, etc were discussed, while individual investigation at each facility were shared among the members. This report is compiled with expectation that it will help promote rational and effective safety management based on GA by sharing contents of the activity widely inside and outside JAEA.
Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Soyama, Kazuhiko
JPS Conference Proceedings (Internet), 33, p.011092_1 - 011092_6, 2021/03
no abstracts in English
Pellegrini, M.*; Herranz, L.*; Sonnenkalb, M.*; Lind, T.*; Maruyama, Yu; Gauntt, R.*; Bixler, N.*; Morreale, A.*; Dolganov, K.*; Sevon, T.*; et al.
Nuclear Technology, 206(9), p.1449 - 1463, 2020/09
Times Cited Count：42 Percentile：97.94(Nuclear Science & Technology)Maruyama, Ryuji; Bigault, T.*; Saerbeck, T.*; Honecker, D.*; Soyama, Kazuhiko; Courtois, P.*
Crystals (Internet), 9(8), p.383_1 - 383_13, 2019/08
Times Cited Count：6 Percentile：48.17(Crystallography)The in-plane magnetic structure of a layered system composed of polycrystalline grains smaller than the ferromagnetic exchange length was studied to elucidate the mechanism controlling the magnetic properties considerably different from the bulk using polarized neutron scattering under grazing incidence geometry. The measured result, together with quantitative analysis based on the distorted wave Born approximation, showed that the in-plane length of the area with uniform orientation of moments ranging from 0.5 to 1.1 
m is not significantly varied during the process of demagnetization followed by remagnetization. The obtained behavior of moments is in good agreement with the two-dimensional random anisotropy model where coherent magnetization rotation is dominant.
Pellegrini, M.*; Herranz, L.*; Sonnenkalb, M.*; Lind, T.*; Maruyama, Yu; Gauntt, R.*; Bixler, N.*; Morreale, A.*; Dolganov, K.*; Sevon, T.*; et al.
Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.1147 - 1162, 2019/08
Maruyama, Ryuji; Yamazaki, Dai; Soyama, Kazuhiko
JPS Conference Proceedings (Internet), 22, p.011011_1 - 011011_5, 2018/11
Neutron multilayer mirrors are one of the most important optical elements for neutron scattering experiments. Good interface quality in terms of sharpness and smoothness plays a critical role in determining the performance of optical elements. We have shown that a multilayer with a large vertical correlation length and small lateral correlation length effectively suppresses the diffuse scattering intensity. In this study, the effect of the interface roughness correlation on the neutron reflectivity of the multilayer mirror is investigated using the reflectivity calculation based on the distorted wave Born approximation.
Maruyama, Ryuji; Yamazaki, Dai; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Miyata, Noboru*; Aoki, Hiroyuki; Takeda, Masayasu; Soyama, Kazuhiko
Nuclear Instruments and Methods in Physics Research A, 888, p.70 - 78, 2018/04
Times Cited Count：6 Percentile：46.52(Instruments & Instrumentation)The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with 
fabricated showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the 
range where the correction for the polarization inefficiencies of the beamline works properly.
Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.
Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09
Neutron devices such as neutron detectors, optical devices including supermirror devices and 
He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.
Maruyama, Ryuji; Bigault, T.*; Wildes, A. R.*; Dewhurst, C. D.*; Saerbeck, T.*; Honecker, D.*; Yamazaki, Dai; Soyama, Kazuhiko; Courtois, P.*
Journal of Physics; Conference Series, 862(1), p.012017_1 - 012017_6, 2017/06
Times Cited Count：6 Percentile：88.40(Physics, Multidisciplinary)The in-plane magnetic structure of Fe/Si multilayers with a polycrystalline grain size less than the ferromagnetic exchange length was investigated using polarized neutron off-specular scattering and grazing-incidence small-angle scattering measurements. These complementary measurements, each of them covering different length scales, together with the data analysis based on the distorted wave Born approximation, revealed lateral correlation in the fluctuating orientation of the magnetization in the layer on a sub-m length scale. The obtained in-plane magnetic structure is consistent with the random anisotropy model, i.e. competition between the exchange interactions between neighboring spins and the local magnetocrystalline anisotropy.
Maruyama, Ryuji; Bigault, T.*; Wildes, A. R.*; Dewhurst, C. D.*; Soyama, Kazuhiko; Courtois, P.*
Nuclear Instruments and Methods in Physics Research A, 819, p.37 - 53, 2016/05
Times Cited Count：8 Percentile：55.98(Instruments & Instrumentation)The in-plane magnetic structure of a layered system with a polycrystalline grain size less than the ferromagnetic exchange length was investigated using polarized neutron off-specular scattering and grazing incidence small angle scattering measurements to gain insight into the mechanism that controls the magnetic properties which are different from the bulk. These complementary measurements with different length scales and the data analysis based on the distorted wave Born approximation revealed the lateral correlation on a length scale of sub-m due to the fluctuating orientation of the magnetization in the layer. The in-plane magnetic structure indicated by these measurements is consistent with the random anisotropy model, i.e. competition between the exchange interactions between neighboring spins and the local magnetocrystalline anisotropy.
Ichimaru, Satoshi*; Takenaka, Hisataka*; Namikawa, Kazumichi*; Gullikson, E. M.*; Maruyama, Momoko; Oku, Satoshi*
Review of Scientific Instruments, 86(9), p.093106_1 - 093106_7, 2015/09
Times Cited Count：3 Percentile：13.77(Instruments & Instrumentation)A graded and broadband Mo/Si multilayer mirror for EUV spectroscopy is demonstrated. This mirror has an average reflectivity profile of 16% in the wavelength region from 15 nm to 17 nm and an effective area of 1100 - 1500 mm
. This reflectivity is about 4 times larger than that of a standard Mo/Si multilayer mirror on a 1 in. diameter substrate, showing that the mirror can be used for measuring EUV fluorescence at wavelengths in the region around 15 nm to 17 nm.
