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JAEA Reports

Nuclear Facilities Management Section Mutsu Office, Aomori Research and Development Center operations report; FY 2012&2013

Tajima, Yoshihiro; Kuwabara, Jun; Oyokawa, Atsushi; Kabuto, Shoji; Araya, Naoyuki; Kikuchi, Kaoru; Miyamoto, Shingo; Nemoto, Hideyuki; Oe, Osamu

JAEA-Review 2016-003, 56 Pages, 2016/05

JAEA-Review-2016-003.pdf:7.16MB

Nuclear Facilities Management Section implements the operation, maintenance and decommissioning of the first nuclear ship "MUTSU" and the operation and maintenance of the liquid waste facility and the solid waste facility where a small amount of nuclear fuel is used. This is the report on the operations of the Nuclear Facilities Management Section for FY 2012 and FY 2013.

Journal Articles

Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator

Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji*; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; et al.

Review of Scientific Instruments, 87(2), p.02B137_1 - 02B137_3, 2016/02

 Times Cited Count:1 Percentile:90.37(Instruments & Instrumentation)

To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of 16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

Journal Articles

Study of negative hydrogen ion beam optics using the 2D PIC method

Miyamoto, Kenji*; Okuda, Shin*; Hatayama, Akiyoshi*; Hanada, Masaya; Kojima, Atsushi

AIP Conference Proceedings 1515, p.22 - 30, 2013/02

 Times Cited Count:8 Percentile:4.56

We have developed the integrated 2D PIC code for the analysis of the negative ion beam optics, in which an overall region from the source plasma to the accelerator is modeled. Thus, the negative ion trajectory can be solved self-consistently without any assumption of the plasma meniscus form initially. This code can reproduce the negative ion beam halo observed in an actual negative ion beam. It is confirmed that the surface produced negative ions which are extracted near the edge of the meniscus can be one of the reasons for the beam halo: these negative ions are over-focused due to the curvature of the meniscus. The negative ions are not focused by the electrostatic lens, and consequently become the beam halo.

Journal Articles

Study of plasma meniscus formation and beam halo in negative hydrogen ion sources

Okuda, Shin*; Miyamoto, Kenji*; Fukuyama, Toshishige*; Nishioka, Shu*; Hatayama, Akiyoshi*; Fukano, Azusa*; Hanada, Masaya; Kojima, Atsushi

AIP Conference Proceedings 1515, p.107 - 113, 2013/02

 Times Cited Count:9 Percentile:3.72

A meniscus of plasma-beam boundary in H$$^{-}$$ ion sources largely affects the extracted H$$^{-}$$ ion beam optics. Recently it is shown that the beam halo is mainly caused by the meniscus, i.e. ion emissive surface, close to the plasma grid (PG) where its curvature is large. The purpose of this study is to clarify the effect of H$$^{-}$$ surface production rate on plasma meniscus and beam halo formation with PIC (particle-in-cell) modeling. It is shown that the plasma meniscus and beam halo formation is strongly dependent on the amount of surface produced H$$^{-}$$ ions.

Journal Articles

Study of beam optics and beam halo by integrated modeling of negative ion beams from plasma meniscus formation to beam acceleration

Miyamoto, Kenji*; Okuda, Shin*; Hatayama, Akiyoshi*; Hanada, Masaya; Kojima, Atsushi

Applied Physics Letters, 102(2), p.023512_1 - 023512_4, 2013/01

 Times Cited Count:18 Percentile:31.29(Physics, Applied)

To understand the physical mechanism of the beam halo formation in negative ion beams, a two-dimensional particle-in-cell code for simulating the trajectories of negative ions created via surface production has been developed. The simulation code reproduces a beam halo observed in an actual negative ion beam. The negative ions extracted from the periphery of the plasma meniscus (an electro-static lens in a source plasma) are over-focused in the extractor due to large curvature of the meniscus.

Journal Articles

Determination of the number of pulsed laser-Compton scattering photons

Kondo, Takeo*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Okamoto, Akiyuki*; Harada, Hideo; Kitatani, Fumito; Shima, Tatsushi*; Horikawa, Ken*; Miyamoto, Shuji*

Nuclear Instruments and Methods in Physics Research A, 659(1), p.462 - 466, 2011/12

 Times Cited Count:20 Percentile:12.92(Instruments & Instrumentation)

We measured pulse-height spectra of 16.7 MeV laser-Compton scattering photons with a 6"$$times$$5" NaI(Tl) detector for blank and three lead materials of 75.8, 50.9, and 25.9% transmissions at the NewSUBARU facility to investigate how the original Poisson distribution of the pulsed photons is modified after passing through thick-target materials. We present a well-prescribed method of determining the number of incident photons within 3.5% accuracy based on the response of the NaI(Tl) detector to the pulsed photon beams.

Journal Articles

Current ramps in tokamaks; From present experiments to ITER scenarios

Imbeaux, F.*; Citrin, J.*; Hobirk, J.*; Hogeweij, G. M. D.*; K$"o$chl, F.*; Leonov, V. M.*; Miyamoto, Seiji; Nakamura, Yukiharu*; Parail, V.*; Pereverzev, G. V.*; et al.

Nuclear Fusion, 51(8), p.083026_1 - 083026_11, 2011/08

 Times Cited Count:34 Percentile:14.26(Physics, Fluids & Plasmas)

Journal Articles

Current ramps in tokamaks; From present experiments to ITER scenarios

Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; Fukuyama, Atsushi*; Garcia, J.*; Gribov, Y. V.*; Hayashi, Nobuhiko; et al.

Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03

Journal Articles

Current ramps in tokamaks; From present experiments to ITER scenarios

Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; Fukuyama, Atsushi*; Garcia, J.*; Gribov, Y. V.*; Hayashi, Nobuhiko; et al.

Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2010/10

In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from several tokamaks have been analyzed by means of integrated modeling in view of determining relevant heat transport models for these operation phases. The results of these studies are presented and projections to ITER current ramp-up and ramp-down scenarios are done, focusing on the baseline inductive scenario (main heating plateau current of 15 MA). Various transport models have been tested by means of integrated modeling against experimental data from ASDEX Upgrade, C-Mod, DIII-D, JET and Tore Supra, including both Ohmic plasmas and discharges with additional heating/current drive. With using the most successful models, projections to the ITER current ramp-up and ramp-down phases are carried out. Though significant differences between models appear on the electron temperature prediction, the final q-profiles reached in the simulation are rather close.

Journal Articles

Thickness distribution of high-speed free-surface lithium flow simulating IFMIF target

Kondo, Hiroo*; Kanemura, Takuji*; Sugiura, Hirokazu*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*

Fusion Engineering and Design, 84(7-11), p.1086 - 1090, 2009/06

 Times Cited Count:7 Percentile:49.38(Nuclear Science & Technology)

A liquid lithium(Li) target of International Fusion Materials Irradiation Facility (IFMIF) is formed as flat plane free-surface flow by a nozzle and flows at high speed around 15 m/s. This paper focuses on flatness of the liquid Li target. A Li flow experiment was conducted in Osaka University Li Loop with a test section which was 1/2.5 scaled model of IFMIF. A thickness of the Li flow was measured and obtained by a contact method which was developed for the measurement. Analytical study on Kelvin wake and numerical calculation on wakes near side walls of the flow channel were also conducted and compared with the experimental results. As the results, positions of wake crest obtained from both of the experiment and numerical calculation assuming contact angle 140$$^{circ}$$ agreed well with an iso-phase line of the analytical model. Generation of the wake are likely depends on wettability between Li and a structural material which is 304SS in the present study.

Journal Articles

Development of velocity measurement on a liquid lithium flow for IFMIF

Sugiura, Hirokazu*; Kondo, Hiroo*; Kanemura, Takuji*; Niwa, Yuta*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; et al.

Fusion Engineering and Design, 84(7-11), p.1803 - 1807, 2009/06

 Times Cited Count:3 Percentile:72.57(Nuclear Science & Technology)

To develop a diagnostics system in view of its application on International Fusion Materials Irradiation Facility (IFMIF) liquid lithium (Li) target, velocity measurements on a liquid Li flow were performed in a Li circulation loop at Osaka University with a test section having a contraction nozzle 1/2.5 scale of IFMIF and producing a flat plane jet of 70 mm width and 10 mm thickness. Based on the Particle Image Velocimetry (PIV) technique, a local Li flow velocity distribution was measured by tracking brightness intensity patterns of surface waves generated on the flow. Measured surface velocity showed good agreement with a surface velocity obtained in previous water experiments, and had an insignificant effect at an area corresponding to a deuteron beam irradiation area on the IFMIF target.

Journal Articles

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution

Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.

Radiochimica Acta, 97(2), p.83 - 89, 2009/02

 Times Cited Count:20 Percentile:17.37(Chemistry, Inorganic & Nuclear)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F, 5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K$$_{d}$$) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta $$approx$$ Nb $$>$$ Db $$geq$$ Pa.

JAEA Reports

Establishment of advanced integration technology for site characterization of deep geological repository; Development of information synthesis and interpretation system; Annual report 2007 (Contract research)

Osawa, Hideaki; Ota, Kunio; Hama, Katsuhiro; Sawada, Atsushi; Takeuchi, Shinji; Amano, Kenji; Saegusa, Hiromitsu; Matsuoka, Toshiyuki; Miyamoto, Tetsuo; Toyoda, Gakuji; et al.

JAEA-Research 2008-085, 742 Pages, 2008/11

JAEA-Research-2008-085-1.pdf:26.22MB
JAEA-Research-2008-085-2.pdf:16.64MB
JAEA-Research-2008-085-3.pdf:28.27MB

This report shows the results the project for the establishment of comprehensive site characterization technology, entrusted from Natural Resources and Energy Agency, Ministry of Economy, Trade and Industry Natural Resources and Energy Agency in 2007.

Journal Articles

Degradation of methylene blue by RF plasma in water

Maehara, Tsunehiro*; Miyamoto, Ippei*; Kurokawa, Kenya*; Hashimoto, Yukio*; Iwamae, Atsushi; Kuramoto, Makoto*; Yamashita, Hiroshi*; Mukasa, Shinobu*; Toyota, Hiromichi*; Nomura, Shinfuku*; et al.

Plasma Chemistry and Plasma Processing, 28(4), p.467 - 482, 2008/08

 Times Cited Count:47 Percentile:10.86(Engineering, Chemical)

Journal Articles

Measuremets of presolar grain in meteorite using neutron activation analysis with multi-parameter coincidence method

Hatsukawa, Yuichi; Miyamoto, Yutaka; Hayakawa, Takehito; Toh, Yosuke; Kimura, Atsushi; Oshima, Masumi

Journal of Radioanalytical and Nuclear Chemistry, 276(1), p.213 - 216, 2008/04

 Times Cited Count:2 Percentile:80.24(Chemistry, Analytical)

Method of multiparameter coincidence spectrometry based on $$gamma$$-$$gamma$$ coincidence is widely used in the field of nuclear structure studies, and has produced many successful achievements. We developed a new technique of trace element analysis based on neutron activation analysis with coincident $$gamma$$-ray detection. In order to improve the low efficiency of coincident $$gamma$$-ray detection, an array of 16 Ge detectors with BGO Compton suppressors was used for this method. High sensitive trace element analyses without chemical separation were carried out by the combination of neutron activation analysis and the method of multiparameter coincidence spectroscopy. In the case of neutron activation analysis, measurements of $$gamma$$-rays from trace elements are strongly interfered by the $$gamma$$-rays from major elements, e.g., $$^{24}$$Na, $$^{56}$$Mn. So usually chemical separation processes are required to eliminate the major elements for determination of the trace elements. But using this method, we can detect very weak $$gamma$$ rays from trace elements without chemical separations. In this study, we try to measure trace elements in presolar grains. Presolar grains are synthesis in the Super nova or Red giant, and found in the primitive meteorite. We obtained presolar grains from the Allende meteorite, and try to measure trace elements in the grains using this method.

Journal Articles

Measurement of free surface of liquid metal lithium jet for IFMIF target

Kondo, Hiroo*; Kanemura, Takuji*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*

Fusion Engineering and Design, 82(15-24), p.2483 - 2489, 2007/10

 Times Cited Count:5 Percentile:59.42(Nuclear Science & Technology)

Lithium flow experiments were conducted for International Fusion Materials Irradiation Facility (IFMIF) at Osaka University. In the experiment, Li plane jet of 10 mm in depth and 70 mm in width formed by a two contractions nozzle was tested in the velocity range of less than 15 m/s. In the present report, Li surface measurement by pattern projection method was tested. This is a three dimensional image measurement, where stripe patterns are projected onto the flow surface without touching it. The projected patterns were observed to be deformed according to the surface up- and- down. Three-dimensional surface shape could be obtained by analyzing the deformed patterns. By the method, shapes of wave pattern called surface wakes were successfully measured. The surface wakes were observed to be formed from the nozzle edge. It was found that the nozzle edge was damaged and became serrated after lithium flowing of 1,300 hours at this moment.

Journal Articles

Investigation of free-surface fluctuations of liquid lithium flow for IFMIF lithium target by using an electro-contact probe

Kanemura, Takuji*; Kondo, Hiroo*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*

Fusion Engineering and Design, 82(15-24), p.2550 - 2557, 2007/10

 Times Cited Count:20 Percentile:17.82(Nuclear Science & Technology)

For a study on characteristics of lithium target flow of International Fusion Materials Irradiation Facility (IFMIF), experiments were carried out by using a lithium loop at Osaka University. In the experiment, fluctuations of a free surface of the horizontal flow were directly measured by using an electro-contact probe acquiring condition of contact/non-contact of the probe with the flow surface as voltage data. Vertical location of the probe tip was set by 0.1 mm step. Horizontal location of the probe was 175 mm downstream from the nozzle exit, corresponding to the footprint of deuteron beam in the IFMIF case. It was found that the maximum amplitude of the surface wave, including rarely arising ones, was 2.2 mm at the center of the flow channel with width of 70 mm at the maximum flow velocity of 15 m/s. The average thickness of the flow was found to be 10.13 mm.

Journal Articles

Establishing priorities for HLW R&D in the 21$$^{st}$$ century

Umeki, Hiroyuki; Naito, Morimasa; Makino, Hitoshi; Osawa, Hideaki; Nakano, Katsushi; Miyamoto, Yoichi; McKinley, I. G.*

Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04

no abstracts in English

Journal Articles

Free-surface fluctuation at high speed lithium flow for IFMIF

Horiike, Hiroshi*; Kondo, Hiroo*; Nakamura, Hiroo; Miyamoto, Seiji*; Yamaoka, Nobuo*; Matsushita, Izuru*; Ida, Mizuho; Ara, Kuniaki; Muroga, Takeo*; Matsui, Hideki*

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03

no abstracts in English

Journal Articles

Key R&D activities supporting disposal of radioactive waste; Responding to the challenges of the 21st century

Miyamoto, Yoichi; Umeki, Hiroyuki; Osawa, Hideaki; Naito, Morimasa; Nakano, Katsushi; Makino, Hitoshi; Shimizu, Kazuhiko; Seo, Toshihiro

Nuclear Engineering and Technology, 38(6), p.505 - 534, 2006/08

Ensuring sufficient supplies of clean, economic and acceptable energy is a critical global challenge for the 21st century. There seems little alternative to a greatly expanded role for nuclear power, but implementation of this option will depend on ensuring that all resulting wastes can be disposed of safely. Although there is a consensus on the fundamental feasibility of such disposal by experts in the field, concepts have to be developed to make them more practical to implement and, in particular, more acceptable to key stakeholders. By considering global trends and using illustrative examples from Japan, key areas for future R&D are identified and potential areas where the synergies of international collaboration would be beneficial are highlighted.

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