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Oikawa, Ryota*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Urayama, Ryoichi*; Nemoto, Yoshiyuki; Takaya, Shigeru; Keyakida, Satoshi*
International Journal of Applied Electromagnetics and Mechanics, 33(3-4), p.1303 - 1308, 2010/10
Times Cited Count：5 Percentile：35(Engineering, Electrical & Electronic)This paper discusses feasibility of non-linear eddy current method to evaluate material degradations of austenitic stainless steels associated with irradiation assisted stress corrosion cracking (IASCC). For the purpose, tensile test at elevated temperature was conducted using model alloys simulating radiation induced segregation (RIS), then magnetization curve of the specimens was measured by vibrating sample magnetometer (VSM), and microstructure of magnetization was observed by magnetic force microscopy (MFM). Moreover non-linear eddy current method was carried out. It was shown that the 3rd higher harmonic ration of the pick-up signal would relate to nominal strain of the specimens.
diffusion in cubic 
-electron compounds observed by high transverse field SRIto, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Heffner, R. H.; Aoki, Yuji*; Suzuki, Hiroyuki*; Onimaru, Takahiro*; Tanida, Hiroshi*; Takagi, Shigeru*
Journal of Physics; Conference Series, 225, p.012021_1 - 012021_6, 2010/06
Times Cited Count：2 Percentile：66.93(Physics, Applied)The diffusion of positive muon in condensed matter has been investigated for many years by using spin rotation/relaxation (SR) technique. The SR studies have provided deep insight into quantum diffusion at low temperatures as well as hopping process at high temperatures, which are closely related to hydrogen dynamics in the dilute limit. We here report transverse field (TF) SR studies of the diffusion in cubic -electron compounds PrPb
and SmAg
In. The site splits into two magnetically labeled sites when high TF is applied to single-crystalline specimens along the [001] direction. The SR lines show drastic variation according to the motion between the magnetically labeled sites. From detailed analysis of the SR lines, we deduced hopping parameters for both compounds.
-ray irradiation facilitiesKaneko, Hirohisa; Hanaya, Hiroaki; Haneda, Noriyuki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Kojima, Takuji; Koyama, Shigeru*; Yamaguchi, Toshiyuki*; Kawashima, Ikuo*; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 209, 2008/03
The accelerator served mainly for graft-polymerization for new material development, radiation effect study on semiconductors, and various experiments of outside users. The annual operation time for the electron accelerator is 597.4h(517h for vertical beams, 80.4h for horizontal beams) The Co-60 -ray irradiation facilities consist of three buildings (8 rooms) and cover a wide dose-rate range from 0.04Gy/h to 20kGy/h with eight irradiation cells. The annual operation time for the cobalt first, second irradiation facilities and food irradiation facility is 20,844 h, 6,335 h and 3,150 h.
-ray irradiation facilitiesKojima, Takuji; Kaneko, Hirohisa; Haneda, Noriyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Koyama, Shigeru*; Yamaguchi, Toshiyuki*; Kawashima, Ikuo*; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 208, 2008/03
An electron accelerator and three ray irradiation facilities were operated for various research subjects as operation plan in FY 2006 without serious trouble. The number of research subjects for the No.1 accelerator, the Cobalt No.1 facility, the Cobalt No.2 facility, and the Food irradiation facility, is 544, 159, 622, and 357, respectively.
-ray irradiation facilitiesKanazawa, Takao; Kaneko, Hirohisa; Haneda, Noriyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Koyama, Shigeru*; Yamaguchi, Toshiyuki*; Kawashima, Ikuo*; Yagi, Norihiko*; et al.
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 200, 2007/02
An electron accelerator and three ray irradiation facilities were operated without any trouble for various experiments in FY 2005. The operation of No.2 accelerator was terminated at April 2005. The number of experimental subjects was 544 for the No.1 accelerator, 287 for the Cobalt No.1 facility, 630 for the Cobalt No.2 facility, and 339 for the Food irradiation facility.
-ray irradiation facilitiesHaneda, Noriyuki; Yamagata, Ryohei; Kaneko, Hirohisa; Hanaya, Hiroaki; Seito, Hajime; Kanazawa, Takao; Koyama, Shigeru*; Kawashima, Ikuo*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 202, 2007/02
The Co-60 -ray irradiation facilities consist of three buildings and cover a wide dose-rate range from 0.04Gy/h to 20kGy/h with eight irradiation cells. All the facilities have been operated without serious trouble and served for the following various R&D's of JAEA and out side users such as development of new materials, radiation resistance test, radiation biotechnology.
SR study in 
ground state system SmAgInIto, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Takagi, Shigeru*; Tanida, Hiroshi*; Suzuki, Hiroyuki*
no journal, ,
no abstracts in English
Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Nemoto, Yoshiyuki; Takaya, Shigeru; Keyakida, Satoshi*
no journal, ,
This paper discusses feasibility of non-linear eddy current method to evaluate material degradations of austenitic stainless steels associated with irradiation assisted stress corrosion cracking. For the purpose, tensile test at elevated temperature was conducted on materials simulating radiation-induced segregation, and non linear harmonic analysis of eddy current was carried out for the tensile test specimens. In addition, microstructure of magnetization of the tensile test specimens was observed by magnetic force microscopy. It was shown that non linear harmonics of eddy current is associated with the Cr depletion and Ni enrichment at grain boundary and intragranular phase transformation.
Oikawa, Ryota*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Urayama, Ryoichi*; Nemoto, Yoshiyuki; Takaya, Shigeru; Keyakida, Satoshi*
no journal, ,
no abstracts in English
Uchimoto, Tetsuya*; Oikawa, Ryota*; Takagi, Toshiyuki*; Urayama, Ryoichi*; Nemoto, Yoshiyuki; Takaya, Shigeru; Keyakida, Satoshi*
no journal, ,
Shibuya, Kentaro*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Takaya, Shigeru
no journal, ,
Magnetic property of aged samples and creep rupture samples of mod. 9Cr-1Mo steel were measured by a nonlinear eddy current method and a magnetic Kerr effect method. Concerning the creep rupture samples, it was found that the equivalent remanent magnetization measured by the nonlinear eddy current method and that measured by the magnetic Kerr effect method are different. This difference may be introduced by change in precipitation of MX carbonnitride and dislocation.
Matsumoto, Takanori*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Takaya, Shigeru
no journal, ,
Mod. 9Cr-1Mo steel is used in advanced fossil power plants. It becomes more important to manage creep damage because temperature and pressure in operating conditions become higher. In this study, it is an objective to evaluate microstructure change due to creep damage by nonlinear eddy current testing. Firstly, relationship between signal of nonlinear eddy current testing and microstructure of creep test samples of mod. 9Cr-1Mo steel was investigated. Next, nonlinear electro-magnetic analysis was performed by using FEM, and then models describe the relation between microstructure and magnetic property was discussed. As result, the possibility of quantitative evaluation of microstructure change due to creep damage by the proposed method is shown.
Matsumoto, Takanori*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Takaya, Shigeru
no journal, ,
The aim of this study is to evaluate microstructure change by creep damage of mod. 9Cr-1Mo steels using electromagnetic nondestructive evaluation. For the purpose, AC magnetization curves of isothermal aging specimens are discussed. Through the comparison between experimental and numerical results, equivalent conductivity and relative permeability are evaluated, and the relationship between microstructure and magnetic properties is discussed.
