Effect of nano-size oxide particle dispersion and -ferrite proportion on creep strength of 9Cr-ODS steel

Otsuka, Satoshi; Kaito, Takeji; Kim, S.-W.; Inoue, Masaki; Asayama, Tai; Onuma, Masato*; Suzuki, Junichi

Materials Transactions, 50(7), p.1778 - 1784, 2009/06

https://doi.org/10.2320/matertrans.M2009096

Existence and origin of compensation layer thickness in TbCo/Pd multilayered films

Tanaka, Masahito*; Asahi, Toru*; Agui, Akane; Mizumaki, Masaichiro*; Sayama, Junichi*; Osaka, Tetsuya*

Journal of Physics D; Applied Physics, 41(5), p.055003_1 - 055003_4, 2008/03

https://doi.org/10.1088/0022-3727/41/5/055003

no abstracts in English

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device

Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.

Nuclear Fusion, 47(10), p.S668 - S676, 2007/10

https://doi.org/10.1088/0029-5515/47/10/S15

The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 510 m, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.

Study on N-added and B-doped effect in Co/Pd multilayered films using soft X-ray absorption and magnetic circular dichroism

Agui, Akane; Asahi, Toru*; Sayama, Junichi*; Kawaji, Jun*; Mizumaki, Masaichiro*; Tanaka, Masahito*; Osaka, Tetsuya*

Journal of Physics D; Applied Physics, 39(14), p.2881 - 2885, 2006/07

https://doi.org/10.1088/0022-3727/39/14/001

no abstracts in English

MCD measurement at the Tb -edges of TbFeCo perpendicular magnetization films

Agui, Akane; Mizumaki, Masaichiro*; Asahi, Toru*; Sayama, Junichi*; Matsumoto, Koji*; Morikawa, Tsuyoshi*; Nakatani, Takeshi; Matsushita, Tomohiro*; Osaka, Tetsuya*; Miura, Yoshimasa*

Transactions of the Magnetics Society of Japan, 4(4-2), p.326 - 329, 2004/11

https://doi.org/10.3379/tmjpn2001.4.326

The electronic and spin state of the perpendicular magnetization film TbFeCo was investigated by means of magnetic circular dichroism spectroscopy for each element. The samples are TbFeCo while the ratio of a rare-earth metal Tb to transition metals Fe and Co is constant, the composition ratio of Fe and Co is changed. Changing the ratio, we estimated the expected orbital moments of Tb 4f electrons. The macroscopic magnetic property is studied from the microscopic point of view.

Thikness dependence of magnetic circular dichroism of TbCo/Pd multi layer films

Tanaka, Masahito*; Asahi, Toru*; Sayama, Junichi*; Agui, Akane; Mizumaki, Masaichiro*; Osaka, Tetsuya*

no journal, , 

no abstracts in English

Development of quantitative evaluation of precipitation method in high Cr steel for FBR using Small-angle Neutron Scattering (SANS)

Obara, Satoshi; Otsuka, Satoshi; Wakai, Takashi; Inoue, Masaki; Asayama, Tai; Suzuki, Junichi; Onuma, Masato*

no journal, , 

no abstracts in English

Quantitative correlation between nano/micro-scale structure and high-temperature strength of 9Cr-ODS steel, 1; Nano/micro-scale structure quantitative analysis using X-ray and neutron small angle scattering technique

Onuma, Masato*; Suzuki, Junichi; Otsuka, Satoshi; Kaito, Takeji; Kim, S.-W.; Inoue, Masaki; Asayama, Tai

no journal, , 

This study discussed the interrelation between chemical composition and nano-scale oxide particle dispersion of the 9Cr-ODS steel for fast reactor fuel cladding application using small angle scattering (SAS) analysis, which is viewed as a strong tool for quantitative evaluation of nano-structure such as particle diameter and number density. Decreasing excess oxygen as well as increasing titanium is shown to provide the considerable increase of nano-scale particle population as well as the reduction of particle diameter. The type of these particles are identified to be YTiO and the number density is evaluated to be in the range between 1E17 and 1E19 (cm). The elevation of hot-extrusion temperature from 1150 C to 1200 C reduced 20% of nano-scale oxide particle number density.

Evaluation of correlation between precipitation dispersion condition and strength of high Cr ferritic heat resistant steels using JRR-3 SANS-J-II

Obara, Satoshi; Suzuki, Junichi; Wakai, Takashi; Inoue, Masaki; Asayama, Tai; Onuma, Masato*

no journal, , 

no abstracts in English

Macroscopic and element selective magnetic properties of TbCo/Pd multilayered and single layered film

Tanaka, Masahito*; Asahi, Toru*; Agui, Akane; Mizumaki, Masaichiro*; Sayama, Junichi*; Osaka, Tetsuya*

no journal, , 

We examined the macroscopic and element selective magnetic properties by Kerr hysteresis loop and X-ray magnetic circular dichroism (MCD) spectroscopy, respectively, of [TbCo]/Pd multilayered films and TbCo single layered films with several TbCo layer thicknesses. We found that the macroscopic magnetic properties of TbCo/Pd and TbCo films were dependent on the TbCo layer thickness by Kerr effect measurement. We estimated the Lz, Sz and Lz/Sz values from MCD measurements at Co L2,3 edges. The values of Lz and Sz of both types of films were the almost same each other, while the clear distinction of Kerr effects was observed.