Measurement of neutron scattering cross section of nano-diamond with particle diameter of approximately 5 nm in energy range of 0.2 meV to 100 meV

Teshigawara, Makoto; Tsuchikawa, Yusuke*; Ichikawa, Go*; Takata, Shinichi; Mishima, Kenji*; Harada, Masahide; Oi, Motoki; Kawamura, Yukihiko*; Kai, Tetsuya; Kawamura, Seiko; et al.

Nuclear Instruments and Methods in Physics Research A, 929, p.113 - 120, 2019/06

https://doi.org/10.1016/j.nima.2019.03.038

A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond was derived from a neutron transmission measurement over the neutron energy range of 0.2 meV to 100 meV because total neutron cross section data were not available. The total cross section of a nano-diamond with particle size of approximately 5 nm increased with a decrease in neutron energy to 0.2 meV. It was approximately two orders of magnitude larger than that of graphite at 0.2 meV. The contribution of inelastic scattering to the total cross section was to be shown negligible small at neutron energies of 1.2, 1.5, 1.9, 2.6, and 5.9 meV in the inelastic neutron scattering measurement. Moreover, small-angle neutron scattering measurements of the nano-diamond showed a large scattering cross section in the forward direction for low neutron energies.

Corrosion properties of F82H in flowing high temperature pressurized water

Nakajima, Motoki; Hirose, Takanori; Tanigawa, Hisashi; Enoeda, Mikio

Journal of Plasma and Fusion Research SERIES, Vol.11, p.69 - 72, 2015/03

http://www.jspf.or.jp/JPFRS/PDF/Vol11/jpfrs2015_11-069.pdf

Water-cooled blanket is an attractive concept for its compactness and its compatibility with the conventional technologies for PWR. For blanket application, the structural material is required to be as thin as possible for tritium breeding. On the other hand, it is also required the pressure tightness to withstand 15 MPa of internal pressure. Therefore it is necessary to understand the corrosion mechanism in high temperature pressurized water. The effects of water flow and DO in the test water on corrosion properties were investigated using rotating disk specimen in autoclave. In summary, the weight loss by flowing was occurred except for test with DO 8 ppm, and it was more pronounced at lower DO concentration. Since FeO was observed on the specimen of small weight change, and the iron-poor layer thickness increased with decreasing the specimen weight, it seemed that the formation of FeO was effective for the suppression of weight loss.

R&D status on water cooled ceramic breeder blanket technology

Enoeda, Mikio; Tanigawa, Hisashi; Hirose, Takanori; Nakajima, Motoki; Sato, Satoshi; Ochiai, Kentaro; Konno, Chikara; Kawamura, Yoshinori; Hayashi, Takumi; Yamanishi, Toshihiko; et al.

Fusion Engineering and Design, 89(7-8), p.1131 - 1136, 2014/10

https://doi.org/10.1016/j.fusengdes.2014.01.035

The development of a Water Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) is being performed as one of the most important steps toward DEMO blanket in Japan. Regarding the fabrication technology development using F82H, the fabrication of a real scale mockup of the back wall of TBM was completed. Also the assembling of the complete box structure of the TBM mockup and planning of the pressurization testing was studied. The development of advanced breeder and multiplier pebbles for higher chemical stability was performed for future DEMO blanket application. From the view point of TBM test result evaluation and DEMO blanket performance design, the development of the blanket tritium simulation technology, investigation of the TBM neutronics measurement technology and the evaluation of tritium production and recovery test using D-T neutron in the Fusion Neutronics Source (FNS) facility has been performed.

Evidence for magnetic-field-induced quadrupolar ordering in the heavy-fermion superconductor PrOsSb

Kogi, Masafumi*; Iwasa, Kazuaki*; Nakajima, Motoki*; Metoki, Naoto; Araki, Shingo; Bernhoeft, N.*; Mignot, J.-M.*; Gukasov, A.*; Sato, Hideyuki*; Aoki, Yuji*; et al.

Journal of the Physical Society of Japan, 72(5), p.1002 - 1005, 2003/05

https://doi.org/10.1143/JPSJ.72.1002

no abstracts in English

Cross section measurement of hydrogen containing materials, 1; Light water and ethanol

Harada, Masahide; Abe, Yutaka*; Teshigawara, Makoto; Oi, Motoki; Ikeda, Yujiro; Oikawa, Kenichi; Nakajima, Kenji; Kawamura, Seiko

no journal, , 

By using neutron instruments, NOBORU and AMATERAS, in J-PARC spallation neutron source, we started to measure temperature dependent total and scattering cross section data of hydrogenous material ranging in thermal and cold neutron region. The cross section data of light water and ethanol were measured.

Compatibility of F82H in flowing high temperature and high pressure water, 1; Effect of testing environment on corrosion behaviour

Nakajima, Motoki; Kanai, Akihiko*; Hirose, Takanori; Tanigawa, Hisashi; Enoeda, Mikio

no journal, , 

no abstracts in English

Effect of test temperature on corrosion properties of F82H in high temperature pressurized water

Nakajima, Motoki; Hirose, Takanori; Tanigawa, Hisashi; Kawamura, Yoshinori

no journal, , 

As the primary candidate of ITER-TBM of Japan, development of WCCB TBM is being performed. In this blanket, the high temperature pressurized water was used as the coolant. Therefore it is necessary to understand the corrosion mechanism in high temperature pressurized water. Additionally, it is also required that understanding of corrosion properties of temperature ranging from 543K to 593K, because inlet and outlet temperatures of TBM are 543K and 593K, respectively. In this study, the corrosion test was performed at temperature ranging from 543K to 593K in high temperature water. Based on the results of corrosion test, the corrosion amount was increased with increasing the test temperature. The corrosion amount of outlet water was two times larger than that of inlet water.

Material properties of weld joints of reduced activation ferritic/martensitic steel, F82H

Hirose, Takanori; Sakasegawa, Hideo; Nakajima, Motoki; Tanigawa, Hiroyasu

no journal, , 

Weld joints of a reduced activation ferritic/martensitic steel, F82H were prepared using Tungsten-Inert-Gas (TIG) and Electron Beam (EB) welding. Physical properties and mechanical properties of these weld joints were investigated in this work. Moreover, effects of Post Weld Heat Treatment (PWHT) was also investigated. After PWHT at 720 C, most of physical properties of weld metal were very similar to those of F82H base metal. Coefficient of thermal expansion and thermal diffusivity of weld metal demonstrated 10% of degradation compared to the base metal. Although weld metal and heat affected zone heated above transformation temperature demonstrated hardening and embrittlement, PWHT above 750 C successfully moderated the hardening without softening in the base metal.

Corrosion properties of RAFM, F82H in high temperature pressurized water

Nakajima, Motoki

no journal, , 

Reduced activation ferritic/martensitic steel, F82H is the most promising candidate structural material for fusion blanket. Water-cooled ceramic breeder blanket is an attractive concept for its compactness and its compatibility with the technologies in conventional pressurized water reactor (PWR). For blanket application, the structural material is required to be as thin as possible for tritium breeding. On the other hand, it is also required the pressure tightness which could withstand internal pressure of 15 MPa. Therefore it is necessary to determine corrosion allowance for cooling tubes precisely. This work reports corrosion properties of F82H in high temperature pressurized water. Moreover, the effects of water flow on corrosion properties were investigated using rotating disk specimen in autoclave.

Phase stability of long term creep tested F82H and its correlation with irradiation resistance

Tanigawa, Hiroyasu*; Nakajima, Motoki*; Sakasegawa, Hideo; Ando, Masami*; Watanabe, Yoshiyuki*; Nozawa, Takashi*; Kato, Yutai*; Nakata, Toshiya*

no journal, ,