Principal preferred orientation evaluation of steel materials using time-of-flight neutron diffraction

Xu, P. G.; Zhang, S.-Y.*; Harjo, S.; Vogel, S. C.*; Tomota, Yo*

Quantum Beam Science (Internet), 8(1), p.7_1 - 7_13, 2024/01

https://doi.org/10.3390/qubs8010007

Measurement of mechanical behavior of B-enriched MgB wire using a pulsed neutron source

Machiya, Shutaro*; Osamura, Kozo*; Hishinuma, Yoshimitsu*; Taniguchi, Hiroyasu*; Harjo, S.; Kawasaki, Takuro

Quantum Beam Science (Internet), 7(4), p.34_1 - 34_17, 2023/10

https://doi.org/10.3390/qubs7040034

Accuracy of measuring rebar strain in concrete using a diffractometer for residual stress analysis

Yasue, Ayumu*; Kawakami, Mayu*; Kobayashi, Kensuke*; Kim, J.; Miyazu, Yuji*; Nishio, Yuhei*; Mukai, Tomohisa*; Morooka, Satoshi; Kanematsu, Manabu*

Quantum Beam Science (Internet), 7(2), p.15_1 - 15_14, 2023/05

https://doi.org/10.3390/qubs7020015

Automated pulsed magnet system for neutron diffraction experiments at the Materials and Life Science Experimental Facility in J-PARC

Watanabe, Masao; Kihara, Takumi*; Nojiri, Hiroyuki*

Quantum Beam Science (Internet), 7(1), p.1_1 - 1_10, 2023/03

https://doi.org/10.3390/qubs7010001

A pulsed magnet system has been developed as a new user-friendly sample environment equipment at the Materials and Life Science Experimental Facility in Japan Proton Accelerator Research Complex. It comprises a vacuum chamber, a 4 K closed-cycle refrigerator for samples, and a nitrogen bath made of a stainless-steel tube with a miniature solenoidal coil. The coil is cooled by liquid nitrogen supplied by an automatic liquid nitrogen supply system, and the sample is cooled by a refrigerator. This combination facilitates the automatic high magnetic field diffraction measurement for the user's operation. A relatively large scattering angle is up to 42 degrees, which is significantly wider than the previous setup. Neutron diffraction experiments were performed on a multiferroic TbMnO and the field dependence of the diffraction peaks was clearly observed. The new pulsed magnet system was established for a practical high magnetic field diffraction for the user program.

Effect of irradiation on corrosion behavior of 316L steel in lead-bismuth eutectic with different oxygen concentrations

Okubo, Nariaki; Fujimura, Yuki; Tomobe, Masakatsu*

Quantum Beam Science (Internet), 5(3), p.27_1 - 27_9, 2021/09

https://doi.org/10.3390/qubs5030027

In an accelerator driven system (ADS), the beam window material of the spallation neutron target is heavily irradiated under severe conditions. Displacement damage and corrosion occur simultaneously because of high-energy neutron and/or proton irradiation in the lead-bismuth flow. The materials used in ADSs need to be compatible with the liquid metal, which is lead-bismuth eutectic (LBE), to prevent issues such as liquid metal embrittlement (LME) and liquid metal corrosion (LMC). In this study, the LMC behavior after ion irradiation of 316L austenitic steel is considered for self-ion irradiations followed by the corrosion tests. The 316L specimens were irradiated by 10.5 MeV-Fe ions at temperature of 450C up to 50 displacement per atom (dpa). After the corrosion test at 450C in LBE with low oxygen concentration, the surface of the non-irradiated area was not oxidized but corrosive morphology with pits, whereas the irradiated area was covered by an iron/chromium oxide layer. The surface of the irradiated area was covered by the duplex layers of iron and iron/chromium oxides in the case of higher oxygen concentration in LBE. It is suggested that irradiation can advance oxide layer formation because of enhanced Fe diffusion caused by the residual vacancies in 316L steel.

Internal strain distribution of laser lap joints in steel under loading studied by high-energy synchrotron radiation X-rays

Shobu, Takahisa; Shiro, Ayumi*; Kono, Fumiaki*; Muramatsu, Toshiharu; Yamada, Tomonori; Naganuma, Masayuki; Ozawa, Takayuki

Quantum Beam Science (Internet), 5(2), p.17_1 - 17_9, 2021/06

https://doi.org/10.3390/qubs5020017

The automotive industries employ laser beam welding because it realizes a high energy density without generating irradiation marks on the opposite side of the irradiated surface. Typical measurement techniques such as strain gauges and tube X-rays cannot assess the localized strain at a joint weld. Herein high-energy synchrotron radiation X-ray diffraction was used to study the internal strain distribution of laser lap joint PNC-FMS steels (2- and 5-mm thick) under loading at a high temperature. As the tensile load increased, the local tensile and compressive strains increased near the interface. These changes agreed well with the finite element analysis results. However, it is essential to complementarily utilize internal defect observations by X-ray transmission imaging because the results depend on the defects generated by laser processing.

Irradiation effects of swift heavy ions detected by refractive index depth profiling

Amekura, Hiroshi*; Li, R.*; Okubo, Nariaki; Ishikawa, Norito; Chen, F.*

Quantum Beam Science (Internet), 4(4), p.39_1 - 39_11, 2020/12

https://doi.org/10.3390/qubs4040039

Evolution of depth profiles of the refractive index in YAlO (YAG) crystals were studied under 200 MeV Xe ion irradiation. The index changes were observed at three different depth regions; (i) a plateau near the surface between 0 and 3 m in depth, which can be ascribed to the electronic stopping Se, (ii) a broad peak at 6 m in depth, and (iii) a sharp dip at 13 m in depth, which is attributed to the nuclear stopping Sn peak.

Double-exposure method with synchrotron white X-ray for stress evaluation of coarse-grain materials

Suzuki, Kenji*; Shiro, Ayumi*; Toyokawa, Hidenori*; Saji, Choji*; Shobu, Takahisa

Quantum Beam Science (Internet), 4(3), p.25_1 - 25_14, 2020/09

https://doi.org/10.3390/qubs4030025

It is difficult to evaluate stress by the strain scanning method using a conventional diffractometer and a point detector since the two-dimensional diffraction pattern of a material composed of coarse grains does not have a ring but a spotty. To solve this problem, we proposed a double exposure method using a two-dimensional detector and monochromatized X-rays. In this study, we have developed a technique to apply that technique to white X-rays. The diffraction obtained by irradiating white X-rays for a material with of coarse grains becomes a Laue spot. Therefore, we have carried out developing a CdTe pixel two-dimensional detector that can limit the energy to be detected, and we evaluated the stress using that detector. As a result, we succeeded to measure the strain distribution of a bending specimen made to austenitic stainless steel. In the future, we would like to improve this technology and apply it to actual machine materials.

Microstructural features and ductile-brittle transition behavior in hot-rolled lean duplex stainless steels

Takahashi, Osamu*; Shibui, Yohei*; Xu, P. G.; Harjo, S.; Suzuki, Tetsuya*; Tomota, Yo*

Quantum Beam Science (Internet), 4(1), p.16_1 - 16_15, 2020/03

https://doi.org/10.3390/qubs4010016

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

https://doi.org/10.3390/qubs1030009

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.