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

Inverted-parabolic and weak strain dependencies on the critical current in practical 110 and 100 oriented REBCO tapes

Osamura, Kozo*; Machiya, Shutaro*; Kajiwara, Kentaro*; Kawasaki, Takuro; Harjo, S.; Zhang, Y.*; Fujita, Shinji*; Iijima, Yasuhiro*; Hampshire, D. P.*

AIP Advances (Internet), 9(7), p.075216_1 - 075216_11, 2019/07

https://doi.org/10.1063/1.5092248

Microstructural characterization of electrodeposited nanocrystalline nickel films by X-ray diffraction

Tanaka, Keisuke*; Koike, Yuki*; Sano, Katsuki*; Tanaka, Hiroto*; Machiya, Shutaro*; Shobu, Takahisa; Kimachi, Hirohisa*

Zairyo, 64(7), p.528 - 535, 2015/07

https://doi.org/10.2472/jsms.64.528

no abstracts in English

Residual strains in ITER conductors by neutron diffraction

Harjo, S.; Hemmi, Tsutomu; Abe, Jun; Gong, W.; Nunoya, Yoshihiko; Aizawa, Kazuya; Ito, Takayoshi*; Koizumi, Norikiyo; Machiya, Shutaro*; Osamura, Kozo*

Materials Science Forum, 777, p.84 - 91, 2014/02

https://doi.org/10.4028/www.scientific.net/MSF.777.84

Neutron diffraction measurement of internal strain in the first Japanese ITER CS conductor sample

Hemmi, Tsutomu; Harjo, S.; Nunoya, Yoshihiko; Kajitani, Hideki; Koizumi, Norikiyo; Aizawa, Kazuya; Machiya, Shutaro*; Osamura, Kozo*

Superconductor Science and Technology, 26(8), p.084002_1 - 084002_6, 2013/08

https://doi.org/10.1088/0953-2048/26/8/084002

JAEA has responsibly to procure all ITER CS conductors. Several conductor samples was fabricated and tested. From the result of the cyclic testing in first conductor sample named JACS01 and second conductor sample named JACS02, the continuous linear degradation of the current sharing temperature () was observed. To investigate the degradation, the visual inspection of JACS01 right leg was performed. As a result, the large deflection at the lower loading side (LLS) in the high field zone (HFZ) was observed. The bending strain of the strands cannot be evaluated from the only deflection obtained by a visual inspection. To evaluate the strain of strands in the conductor sample quantitatively, the neutron diffraction measurement of JACS01 left leg was performed using the engineering materials diffractometer in J-PARC. From the result, the large bending strain at the LLS in the HFZ was observed. Therefore, the degraded position in the conductor sample can be determined.

Neutron diffraction measurements of internal strain in NbSn cable-in-conduit conductors

Hemmi, Tsutomu; Harjo, S.; Ito, Takayoshi; Matsui, Kunihiro; Nunoya, Yoshihiko; Koizumi, Norikiyo; Takahashi, Yoshikazu; Nakajima, Hideo; Aizawa, Kazuya; Suzuki, Hiroshi; et al.

IEEE Transactions on Applied Superconductivity, 21(3), p.2028 - 2031, 2011/06

https://doi.org/10.1109/TASC.2010.2089770

Residual strain in conductors is caused by the difference in the coefficient of expansion between NbSn strands and the jacket over a temperature range of 5 - 923 K. The superconducting properties of strands vary significantly, depending on the strain. It is important to clarify the residual strain as part of the evaluation of superconducting performance. However, the residual strain of strands in the conductor has not been measured so far because of their complicated configuration and their location in a jacket. The engineering materials diffractometer "Takumi" in J-PARC can measure residual strain with a relative accuracy of around 0.02%, using neutron diffraction. In this study, the Takumi was applied to the measurement of residual strain in strands for the ITER TF conductor. Results indicate that the residual strain of strands in the conductor can be determined, thereby clarifying the mechanism of residual strain and its relationship to superconducting performance.

Force free strain exerted on a YBCO layer at 77 K in surround Cu stabilized YBCO coated conductors

Osamura, Kozo*; Machiya, Shutaro*; Tsuchiya, Yoshinori*; Suzuki, Hiroshi

Superconductor Science and Technology, 23(4), p.045020_1 - 045020_7, 2010/04

https://doi.org/10.1088/0953-2048/23/4/045020

The stress/strain behavior of the surround Cu stabilized YBCO coated conductors and its influence on critical current were precisely investigated. The internal strain exerted on the superconducting YBCO layer was determined at 77 K by using a neutron diffraction technique at JAEA. The initial compressive strain decreased during tensile loading and changed to a tensile component at the force free strain (A), where the internal uniaxial stress becomes zero in the YBCO layer. The A was evaluated to be 0.19-0.21% at 77 K. The critical current measurements were carried out under a uniaxial tensile load at 77 K. The strain dependence revealed a characteristic behavior, where a maximum was observed at 0.035%. Thus it was made clear that the strain at the critical current maximum does not correlate with A for YBCO coated conductors.

Application of neutron engineering diffractometer RESA in cryogenic engineering

Suzuki, Hiroshi; Tsuchiya, Yoshinori*; Machiya, Shutaro*; Osamura, Kozo*; Akita, Koichi

no journal, , 

Neutron diffraction method can measure a strain inside materials at centimeter-order depth non-destructively. Besides, the neutron diffraction method enables us to evaluate microstructural factors such as texture, dislocation density and block size by analyzing the broadening of the diffraction profile. Therefore, the neutron diffraction is very useful technique in the design and development of engineering components, as well as in studies on materials engineering. In the cryogenic engineering field, it is important to know the characteristics of engineering materials at low temperatures. In particular, evaluations of residual strains as well as deformation behavior at low temperatures are required to improve the strength and functionality of cryogenic materials. To achieve such materials evaluation at low temperatures, we have developed a cryogenic load frame for neutron diffraction. In the presentation, the angular dispersive neutron engineering diffractometer, RESA, located in the JRR-3 (Japan Research Reactor No. 3) guide hall will be introduced including application studies with the developed cryogenic load frame.

Evaluation on tube stress distribution of sodium heated steam generator by neutron diffraction method, 1

Suzuki, Hiroshi; Machiya, Shutaro; Akiniwa, Yoshiaki; Kasahara, Naoto; Kisohara, Naoyuki

no journal, , 

no abstracts in English

Strain measurements of superconducting filaments and Ag-alloy using neutron diffraction in Ag-sheathed Bi2223 tapes

Machiya, Shutaro; Osamura, Kozo*; Suzuki, Hiroshi; Shiota, Yoshinori*; Ayai, Naoki*; Hayashi, Kazuhiko*; Sato, Kenichi*

no journal, , 

In situ strain measurement was made for inner Bi2223 filaments and outer Ag alloy in the Ag-sheathed Bi2223 tapes using neutron diffraction. The residual strain and the strain response under the axial tensile loading were measured in the Ag-sheathed Bi2223 tapes stacked with 10 sheets.