Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kojima, Satoru*; Kagami, Saya; Yokoyama, Tatsunori; Kariya, Yoshihiko*; Katayama, Yoshikazu*; Nishio, Gaku*
Proceedings of 5th International Workshop on Rock Mechanics and Engineering Geology in Volcanic Fields (RMEGV 2021) (Internet), 6 Pages, 2021/09
A local tephra embedded in a hand-auger boring core drilled at near-shore of Kinugasanoike Pond about 4.6 km NE of Mt.Yakedake, one of the most active volcanoes in central Japan, is composed mainly of several kinds of volcanic glass shards (microlite-bearing, blocky, fluted and micro-vesicular types) with minor amounts of crystal minerals including quartz, plagioclase, hornblende, biotite, and pyroxene. Plant remains recovered from the horizon 10 cm below the tephra layer yield 
C ages of 2,331-2,295 (19.2% probability distribution) and 2,270-2,155 (76.2% probability distribution) cal yrs BP. We measured major element compositions of 241 individual glass shards using Electron Probe Micro Analyzer. They are plotted on the SiO
-KO, SiO-NaO+KO, and FeO
-KO diagrams in a region different from those of major regional tephras distributed in central Japan. The clast and chemical compositions coincide with those of a tephra embedded in the Nakao pyroclastic flow deposits distributed about 2 km NNW of Mt. Yakedake dated as around 2,300 cal yrs BP. The tephra could be used as a local marker of 2,300 cal yrs BP in the southern part of Northern Japan Alps.
Taniguchi, Naoki; Nakayama, Masashi
Zairyo To Kankyo, 67(12), p.487 - 494, 2018/12
This article describes the current status of corrosion monitoring methods and examples of the measurement under deep underground environments for carbon steel overpacks for high-level radioactive waste disposal. Based on the studies on corrosion monitoring using AC Impedance technique, some of the typical measurement systems such as the electrodes arrangement are introduced. In-situ corrosion monitoring in engineering scale test is also being attempted using a deep underground research facility, and the measurement method and results are presented in this article.
Adhi, P. M.*; Okubo, Nariaki; Komatsu, Atsushi; Kondo, Masatoshi*; Takahashi, Minoru*
Energy Procedia, 131, p.420 - 427, 2017/12
Times Cited Count：0 Percentile：0.03(Energy & Fuels)The ionic conductivity of solid electrolyte may insufficient, and the sensor output signal will deviate from the theoretical one in low temperature. The performance of oxygen sensor with Ag/air reference electrode (RE) and liquid Bi/BiO
RE was tested in low-temperature LBE at 300
450
C and the charge transfer reactions impedance at the electrode-electrolyte interface was analyzed by electrochemical impedance analysis (EIS). After steady state condition, both of the sensors performed well and can be used at 300450C. Bi/Bi/BiO RE has lower impedance than Ag/air RE. Therefore, the response time of the oxygen sensor with Bi/Bi/BiO RE is faster than the oxygen sensor with Ag/air RE in the low-temperature region.
Furukawa, Tomohiro; Hirakawa, Yasushi; Kondo, Hiroo; Kanemura, Takuji
Nuclear Materials and Energy (Internet), 9, p.286 - 291, 2016/12
Times Cited Count：5 Percentile：36.53(Nuclear Science & Technology)In order to exchange the components which received irradiation damage during the operation at the International Fusion Materials Irradiation Facility, the adhered lithium, which is partially converted to lithium compounds such as lithium oxide and lithium hydroxide, should be removed from the components. In this study, the dissolution experiments of lithium compounds (lithium nitride, lithium hydroxide, and lithium oxide) were performed in a candidate solvent, allowing the clarification of time and temperature dependence. Based on the results, a cleaning procedure for adhered lithium on the inner surface of the components was proposed.
Hoshino, Kazuo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 92(2), p.146 - 147, 2016/02
no abstracts in English
Okumura, Yoshikazu; Gobin, R.*; Knaster, J.*; Heidinger, R.*; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; et al.
Review of Scientific Instruments, 87(2), p.02A739_1 - 02A739_3, 2016/02
Times Cited Count：7 Percentile：35.23(Instruments & Instrumentation)IFMIF is an accelerator based neutron facility having two set of linear accelerators each producing 125mA/CW deuterium ion beams (250mA in total) at 40MeV. The LIPAc (Linear IFMIF Prototype Accelerator) being developed in the IFMIF-EVEDA project consists of an injector, a RFQ accelerator, and a part of superconducting Linac, whose target is to demonstrate 125mA/CW deuterium ion beam acceleration up to 9MeV. The injector has been developed in CEA Saclay and already demonstrated 140mA/100keV deuterium beam. The injector was disassembled and delivered to the International Fusion Energy Research Center (IFERC) in Rokkasho, Japan, and the commissioning has started after its reassembly 2014; the first beam production has been achieved in November 2014. Up to now, 100keV/120mA/CW hydrogen ion beam has been produced with a low beam emittance of 0.2 
.mm.mrad (rms, normalized).
Hoshino, Kazuo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 91(12), p.802 - 803, 2015/12
Holding of the 17th IFERC Project Committee (PC), the 16th IFMIF/EVEDA-PC and the progress of the JT-60SA were reported. In the IFERC-PC, total 33 participated including Maisonnier chairperson, JA-EU committee, experts and project members. They reported the status of each activity, discussed the planning of project 2016 and revised plan, and concluded technical advice to the BA Steering Committee (SC). In the IFMIF/EVEDA-PC, total 27 participated including Takatsu chairperson, JA-EU committee, experts and project members. They reported the status of each activity, discussed the planning of project 2016 and revised plan, and the BA-SC recommended the endorsement of the new project plan. In the JT-60SA, a rotary crane for assembly of the troidal field coil has been installed. The disassembly of the constraint jigs of the vacuum vessel which completed 340 assembly has been progressed. 6 high temperature superconductor current leads for the troidal field coils had been delivered from EU.
Hoshino, Kazuo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 91(10), p.700 - 701, 2015/10
The progress of IFMIF Prototype Accelerator in the IFERC site and the Satellite Tokamak (JT-60SA) project were reported. For the IFMIF Prototype Accelerator, two radio frequency (RF) sources of the RF quadrupole accelerator, seven high-voltage power supplies, and distribution cabinets were delivered from the CIEMAT institute in Spain and the installation was started. In the Satellite Tokamak project, the development for long term operation technique of the neutral beam injector has been achieved and thereby confirmed to be feasible for long term operation of JT-60SA. The 340 torus assembly of vacuum vessel of the JT-60SA, which was started from May last year, has been completed. To send out information to the domestic community a major event in the BA activities.
Maebara, Sunao; Sukegawa, Keiichi*; Tadano, Shuya*; Kasugai, Atsushi; Suzuki, Hiromitsu; Abe, Kazuhiko*; Oku, Ryuji*; Sugimoto, Masayoshi
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1140 - 1142, 2015/09
For the IFMIF/EVEDA accelerator prototype RFQ linac, the operation frequency of 175MHz was selected to accelerate a large current of 125mA. The driving RF power of 1.28MW by 8 RF input couplers has to be injected to the RFQ cavity for CW operation mode. For each RF input coupler, nominal RF power of 160kW and maximum transmitted RF power of 200kW are required. For this purpose, an RF input coupler with cooling functions was designed, based on a 6 1/8 inch co-axial waveguide, and the RF coupler was manufactured by way of trial. For the trial RF coupler, high-power tests using a high voltage standing wave on a high-Q load circuit wave were carried out, and a 200kW-14 sec CW operation were performed after four days of RF aging. No RF contact defects, unnecessary low-Q value and extraordinary outgassing were observed. This report describes the high-power tests of the RF input coupler.
Usami, Hiroki; Takahashi, Hiroki; Komukai, Satoshi*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.760 - 763, 2015/09
EU and JAEA are advancing development of Linear IFMIF Prototype Accelerator (LIPAc) control system jointly, but JAEA keeps developing central control system (CCS) mainly. Data transfer during an equipment control system of CCS and EU is performed through EPICS. JAEA is using PostgreSQL as 1 of development elements in CCS and is advancing development of the system to record the whole EPICS data of LIPAc (the data acquisition system). On the other hand, a data acquisition is performed using BEAUTY (Best Ever Archive Toolset, yet) in an element test of equipment at Europe. Therefore "1 client refers to collected data by more than one server machine" with "compatibility securement of data with BEAUTY" in case of development of the data acquisition system of CCS, and, it's necessary to consider "To do a data acquisition and backup work at the same time". For the moment, former 2 are in progress. And a demonstration of the data acquisition system is being performed simultaneously with commissioning in injector. The data acquisition system is collecting data of injector other ones, and the data reference by a monitor with CSS (Control System Studio) is also possible. We will report on the current state of the development of the data acquisition system by making reference to a result of the test by injector commissioning.
Okumura, Yoshikazu; Ayala, J.-M.*; Bolzon, B.*; Cara, P.*; Chauvin, N.*; Chel, S.*; Gex, D.*; Gobin, R.*; Harrault, F.*; Heidinger, R.*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.203 - 205, 2015/09
Under the framework of Broader Approach (BA) agreement between Japan and Euratom, IFMIF/EVEDA project was launched in 2007 to validate the key technologies to realize IFMIF. The most crucial technology to realize IFMIF is two set of linear accelerator each producing 125mA/CW deuterium ion beams up to 40MeV. The prototype accelerator, whose target is 125mA/CW deuterium ion beam acceleration up to 9MeV, is being developed in International Fusion Research Energy Center (IFERC) in Rokkasho, Japan. The injector developed in CEA Saclay was delivered in Rokkasho in 2014, and is under commissioning. Up to now, 100keV/120mA/CW hydrogen ion beams and 100keV/90mA/CW duty deuterium ion beams are successfully produced with a low beam emittance of 0.21 .mm.mrad (rms, normalized). Delivery of RFQ components will start in 2015, followed by the installation of RF power supplies in 2015.
Hoshino, Kazuo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 91(8), p.561 - 562, 2015/08
The new construction of Joint Research Building for the DEMO R&D at IFERC, progress of the IFMIF Prototype Accelerator and the Satellite Tokamak (JT-60SA) project were reported. The Joint Research Building processing the construction as a new place where carry out a part of project for the DEMO R&D in the rest of the BA activity period and it mainly consists of the laboratory/material testing room for the material evaluation and Be production room for handling of the metal beryllium. For the IFMIF Prototype Accelerator, completed the repairs and test run of the Interlock, successful of the continuity rated proton beam, then after setting of the radiation control area, successful production of the deuterium ion beam. For the JT-60SA, the installation of a Helium refrigerator which is one of the world's largest and a He buffer tank have been completed. The 4th Research Coordination meeting was held and they discussed the research plan and theme for the experiment proposal of JT-60SA.
Hoshino, Kazuo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 91(6), p.430 - 431, 2015/06
Holding of the 16th BA Steering Committee and progress of the Satellite Tokamak (JT-60SA) project were reported. There were 33 participants for the 16th BA Steering Committee, including 3 committee members and 10 specialists from EU, 4 committee and 11 specialists from JP, each project leaders and project committee chair persons, and they approved for update of the 2014 Annual Report and the Work Plan of IFMIF/EVEDA, the IFERC and the Satellite Tokamak project. In the construction of JT-60SA, the component carry-in from EU and the assembly has been progressed steadily in JP. To announce for these progressing, a ceremony was held and 200 people concerned in EU-JP attended. The 22nd JT-60SA Technical Coordination Meeting was held. 73 people EU-JP joined and had discussion regarding the design, status of production, examination of assembly and the integrate operation in the future. To send out information to the domestic community a major event in the BA activities.
Kondo, Hiroo; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Wakai, Eiichi
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 8 Pages, 2015/05
A liquid-Li free-surface stream is to serve as a beam target (Li target) for the IFMIF. As a major activity for the Li target in the IFMIF/EVEDA, the EVEDA Li test loop (ELTL) was constructed. This study focuses on cavitation-like acoustic noise in a conduit downstream of the Li target. This noise was detected by using acoustic-emission sensors. The intensity of the noise was examined versus cavitation number of the Li target. In addition, a time-frequency analysis for the acoustic signal was performed to characterize the noise. The results are as follows: (1) the intensity of the noise was increased as decreasing the cavitation number; (2) the noise was at first intermittent in a larger cavitation number, subsequently the noise became continuous as decreasing the cavitation number; (3) the noise consisted of a number of a high frequency acoustic emission which occurred in a short duration. For these results, we conclude that cavitation occurred in the downstream conduit.
Ishii, Yasutomo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 91(2), p.161 - 162, 2015/02
Success of the first beam of injector for IFMIF prototype accelerator, accomplishment of liquid Lithium Target validation test of the IFMIF/EVEDA and the progress of Satellite Tokamak (JT-60SA) were reported. The IFMIF/EVEDA project are performed in International Fusion Energy Research Center at Rokkasho under the BA agreement, installation and adjustment of injector for IFMIF accelerator were completed and the adjustment beam test has started from Nov. 2014. For the engineering validation test, formability of the Lithium Target which become the neutron source, the Lithium Test Loop of real scale was fabricated in Oarai and test has been conducted for 2 years. At the end of Oct. 2014, made an exceeding achievement and successfully concluded. In the construction of JT-60SA at Naka, the design of each part has been performing with the 3D CAD soft CATIA. The update with previous state discloses on JT60-SA HP. To disseminate information to the domestic community a major event in the BA activities.
Ishii, Yasutomo; Matsunaga, Go; Okumura, Yoshikazu
Purazuma, Kaku Yugo Gakkai-Shi, 90(12), p.827 - 828, 2014/12
Holding of the 15th BA Steering Committee, the 14th IFMIF/EVADA business meeting, the 15th IFERC business meeting and the progress of the Satellite Tokamak (JT-60SA) plan were reported. There were participation of 3 committee members and 8 specialists from EU side and also 30 people which is 4 committees, 7 specialists, each project leaders and project committee chair persons, for the 15th BA Steering Committee and approved for the 2015 Work Plan of IFMIF/EVADA project, the IFERC project and the Satellite Tokamak.6 committees (3 EU side, 3 Japan side), 12 specialists (5 EU, 7 JP) and 8 members of IFMIF/EVADA team, for the 14th IFMIF/EVADA meeting and progress of the each activities were reported.6 committees (3 EU, 3 JP), 16 specialists (9 EU, 7 JP) and 9 members of IFERC team, for the 15th IFERC meeting and reported on progress and discussed about the 2015 Work Plan. In the progress of the JT-60SA plan, assembly work of vacuum chamber is proceeding smoothly in the JT-60 main body room.
Wakai, Eiichi; Kondo, Hiroo; Kanemura, Takuji; Hirakawa, Yasushi; Furukawa, Tomohiro; Hoashi, Eiji*; Fukada, Satoshi*; Suzuki, Akihiro*; Yagi, Juro*; Tsuji, Yoshiyuki*; et al.
Proceedings of Plasma Conference 2014 (PLASMA 2014) (CD-ROM), 2 Pages, 2014/11
In the IFMIF/EVEDA (International Fusion Materials Irradiation Facility/ Engineering Validation and Engineering Design Activity), the validation tests of the EVEDA lithium test loop with the world's highest flow rate of 3000 L/min was succeeded in generating a 100 mm-wide and 25 mm-thick free-surface lithium flow steadily under the IFMIF operation condition of a high-speed of 15 m/s at 250C in a vacuum of 10 
Pa. Some excellent results of the recent engineering validations including lithium purification, lithium safety, and remote handling technique were obtained, and the engineering design of lithium facility was also evaluated. These results will advance greatly the development of an accelerator-based neutron source to simulate the fusion reactor materials irradiation environment as an important key technology for the development of fusion reactor materials.
Ishii, Yasutomo; Matsunaga, Go
Purazuma, Kaku Yugo Gakkai-Shi, 90(8), p.506 - 507, 2014/08
This time, the 5th LIPAc Technical Meeting on June 3-5, Acceptance testing of the RF system for the prototype accelerator, start assembling the JT-60SA vacuum vessel from May, and the 3rd EU-Japan JT-60SA research coordination meeting on May 19-23 are reported. The 5th LIPAc Technical Meeting, Installation in Rokkasho, situation of adjustment work, and preparation status, 38 topics from each agency in each equipment have been reported. In addition, the performance test of RF system for the prototype accelerator that Europe procures was conducted under JAEA, F4E and the project team attendance. Good test results are obtained. The Superconducting tokamak JT-60SA vacuum vessel has started assembling from May. The 3rd JT-60SA EU-Japan Research Coordination Meeting, formulation of a research plan of JT-60SA, and discussion and information exchange of Japanese and EU joint research on JT-60SA were done. To disseminate information to the domestic community a major event in the BA activities.
Abe, Kanako*; Nakajima, Hideo; Hamada, Kazuya; Okuno, Kiyoshi; Kakui, Hideo*; Yamaoka, Hiroto*; Maruyama, Naoyuki*
IEEE Transactions on Applied Superconductivity, 16(2), p.807 - 810, 2006/06
Times Cited Count：11 Percentile：51.53(Engineering, Electrical & Electronic)no abstracts in English
Oyama, Naoyuki; Gohil, P.*; Horton, L. D.*; Hubbard, A. E.*; Hughes, J. W.*; Kamada, Yutaka; Kamiya, Kensaku; Leonard, A. W.*; Loarte, A.*; Maingi, R.*; et al.
Plasma Physics and Controlled Fusion, 48(5A), p.A171 - A181, 2006/05
Times Cited Count：81 Percentile：92.09(Physics, Fluids & Plasmas)no abstracts in English
