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Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：6 Percentile：84.97(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
single-crystal time-of-flight neutron diffractometer at J-PARC/MLFKawasaki, Takuro; Nakamura, Tatsuya; To, Kentaro; Hosoya, Takaaki*; Oikawa, Kenichi; Ohara, Takashi; Kiyanagi, Ryoji; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru; et al.
Nuclear Instruments and Methods in Physics Research A, 735, p.444 - 451, 2014/01
Times Cited Count：18 Percentile：80.14(Instruments & Instrumentation)Nakamura, Tatsuya; Kawasaki, Takuro; Hosoya, Takaaki*; To, Kentaro; Oikawa, Kenichi; Sakasai, Kaoru; Ebine, Masumi; Birumachi, Atsushi; Soyama, Kazuhiko; Katagiri, Masaki*
Nuclear Instruments and Methods in Physics Research A, 686, p.64 - 70, 2012/09
Times Cited Count：31 Percentile：90.36(Instruments & Instrumentation)A two-dimensional scintillator-based neutron detector that has a neutron-sensitive area of 256 
256 mm
with a pixel size of 4 mm was developed. The detector was designed to be compact and modular with the smallest dead area for the SENJU time-of-flight Laue single-crystal diffractometer to be constructed in the Materials and Life Experimental Science Facility at the Japanese Proton Accelerator Research Complex. Two ZnS/
scintillator screens with an optimized scintillator thickness sandwiched the cross-arranged Wavelength-shifting fibre arrays to ensure a high detection efficiency for thermal neutrons. The prototype detector exhibited a detector efficiency of 40 
1 % for 1.6-
neutrons and a 
Co 
-ray sensitivity of 6.00.1 
, which fulfilled the required detector specifications for SENJU.
Ueda, Yoshio*; Oya, Kaoru*; Ashikawa, Naoko*; Ito, Atsushi*; Ono, Tadayoshi*; Kato, Daiji*; Kawashima, Hisato; Kawamura, Gakushi*; Kenmotsu, Takahiro*; Saito, Seiki*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 88(9), p.484 - 502, 2012/09
no abstracts in English
Oya, Kaoru*; Inai, Kensuke*; Shimizu, Katsuhiro; Takizuka, Tomonori; Kawashima, Hisato; Hoshino, Kazuo; Hatayama, Akiyoshi*; Toma, Mitsunori*; Tomita, Yukihiro*; Kawamura, Gakushi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 85(10), p.695 - 703, 2009/10
no abstracts in English
Oya, Kaoru*; Inai, Kensuke*; Kikuhara, Yasuyuki*; Nakano, Tomohide; Kawata, Jun*; Kawazome, Hayato*; Ueda, Yoshio*; Tanabe, Tetsuo*
Journal of Plasma and Fusion Research SERIES, Vol.8, p.419 - 424, 2009/09
Redeposition of C
H
and CH
chemically eroded from carbon walls is simulated by EDDY code incorporated with the reflection on a hydrogenated and amorphized carbon surface. The redeposition rate for heavy hydrocarbons is drastically decreased by introduction of the reflection. The redeposition patterns on the surface are enlarged by the reflection, but it is narrower for the heavy hydrocarbons than for CH. The photon emissions of C from CH (CH) decay faster than that of CH from CH in high-temperature (
10 eV) plasmas, which reproduces the difference of the decay of the CD and C light intensities observed in the vicinity of the outer diverter plates of JT-60U. For such temperatures, the inverse photon-efficiency, which is defined as the ratio of the number of the launching hydrocarbons to the photoemission events of CH and C, is in good agreement with the values observed in JT-60U experiments.
Ebisawa, Hiroyuki; Hanakawa, Hiroki; Asano, Norikazu; Kusunoki, Hidehiko; Yanai, Tomohiro; Sato, Shinichi; Miyauchi, Masaru; Oto, Tsutomu; Kimura, Tadashi; Kawamata, Takanori; et al.
JAEA-Technology 2009-030, 165 Pages, 2009/07
JAEA-Technology-2009-030.pdf:69.18MB
The condition of facilities and machinery used continuously were investigated before the renewal work of JMTR on FY 2007. The subjects of investigation were reactor building, primary cooling system tanks, secondary cooling system piping and tower, emergency generator and so on. As the result, it was confirmed that some facilities and machinery were necessary to repair and others were used continuously for long term by maintaining on the long-term maintenance plan. JMTR is planed to renew by the result of this investigation.
Hoshino, Kazuo; Toma, Mitsunori*; Furubayashi, Masahiko*; Hatayama, Akiyoshi*; Inai, Kensuke*; Oya, Kaoru*
Journal of Nuclear Materials, 390-391, p.168 - 171, 2009/06
Times Cited Count：4 Percentile：30.49(Materials Science, Multidisciplinary)The self-sputtering yield and the reflection yield are important for a prediction of the tungsten impurity content penetrating into the main plasma in future fusion reactors. These yields greatly depend on the incident angle of impurities to the plasma facing components. The IMPGYRO code is applied to the analysis of the angle distribution of incident impurities and the effect of the incident angle and energy on the sputtering and reflection yields. The incident angle distribution is divided into several peaks corresponding to charge states. This is caused by the different acceleration for each charge state by the sheath. In the attached plasma case, the sheath increases the self-sputtering yield. This is due to the change of the incident angle by the sheath rather than the change of the incident energy. On the other hand, in the detached plasma case, the significant effects of the sheath on the sputtering yield and the reflection yield is not seen.
Shimizu, Katsuhiro; Takizuka, Tomonori; Oya, Kaoru*; Inai, Kensuke*; Nakano, Tomohide; Takayama, Arimichi*; Kawashima, Hisato; Hoshino, Kazuo
Nuclear Fusion, 49(6), p.065028_1 - 065028_9, 2009/06
Times Cited Count：60 Percentile：89.24(Physics, Fluids & Plasmas)The self-consistent coupling of a Monte Carlo (MC) impurity code IMPMC to a divertor code SOLDOR/NEUT2D has been succeeded. MC modelling is required for impurity transport in order to take into account the kinetic effect and the complex dissociation processes of hydrocarbons. The integrated divertor code SONIC enables us to investigate the details of impurity transport including erosion/redeposition processes on the divertor plates by further coupling of an MC code EDDY. The dynamic evolution of X-point MARFE observed in JT-60U is investigated. The simulation results indicate that the hydrocarbons sputtered from the dome contribute to the enhanced radiation near the X-point. The kinetic effect of thermal force on the He transport is investigated for JT-60SA detached plasmas. Without the recycling, the kinetic effect improves the helium compression, compared with the conventional (fluid) evaluation. This effect is, however, masked by the recycling at the divertor targets.
Shimizu, Katsuhiro; Takizuka, Tomonori; Oya, Kaoru*; Inai, Kensuke*; Nakano, Tomohide; Takayama, Arimichi*; Kawashima, Hisato; Hoshino, Kazuo
Proceedings of 22nd IAEA Fusion Energy Conference (FEC 2008) (CD-ROM), 12 Pages, 2008/10
The self-consistent coupling of an MC impurity code IMPMC to a divertor code SOLDOR/NEUT2D is succeeded by overcoming the intrinsic problems of Monte Carlo (MC) modelling for impurity transport. MC modelling for impurity transport is required in order to take into account the kinetic effect and the complex dissociation processes of hydrocarbons. The integrated divertor code SONIC enables us to investigate the details of impurity transport including erosion/redeposition processes on the divertor plates by further coupling of an MC code EDDY. The dynamic evolution of X-point MARFE observed in JT-60U is investigated. The simulation results indicate that the hydrocarbons sputtered from the dome contribute directly to the enhanced radiation near the X-point. Without the recycling, the kinetic effect of the thermal force improves the helium compression, compared with the conventional (fluid) evaluation. This effect is, however, masked by the recycling at the divertor targets.
Nakamura, Tatsuya; Sakasai, Kaoru; Katagiri, Masaki; Birumachi, Atsushi; Hosoya, Takaaki; Soyama, Kazuhiko; Sato, Setsuo*; Shooneveld, E.*; Rhodes, N.*
JAEA-Research 2007-014, 14 Pages, 2007/03
JAEA-Research-2007-014.pdf:1.9MB
The ENGIN-X type linear scintillation neutron detector was manufactured in Japan and the detector performances were evaluated. The ENGIN-X type linear scintillation neutron detector was originally developed by the detector group in Rutherford Appleton Laboratory and the Japanese prototype detector was identical to that which is one of the detector modules installed in the ENGIN-X diffractometer at ISIS pulsed neutron source. The prototype detector can install 240 elements of neutron-sensitive scintillator, where each element has 3 mm in width and 196 mm in length. The prototype detector exhibited a spatial resolution of 3 mm, detection efficiency of 64% for neutrons with wave-lengths of 1.8, count uniformity of 6
7%, Co sensitivity of 510
. Technological transfer to the Japanese manufacturer was done successfully and the mass production of these detectors for the J-PARC project is feasible.
Yokoya, Akinari; Takakura, Kaoru*; Watanabe, Ritsuko; Akamatsu, Ken*; Ito, Takashi*
Radiation Research, 162(4), p.469 - 473, 2004/10
Radicals induced in a single crystal of 5-bromouracil (BrUra) by synchrotron soft X-rays in the Br K-edge region (13.461-13482 keV) were investigated using the X-band EPR method. The crystal was irradiated at three peak energies in the absorption spectrum at room temperature or at 80K. A hydrogen abstraction radical derived from N1 atom of the pyrimidine ring was commonly observed for all of the energies used, though with some variation in quantity. Similar characteristics were also observed in the EPR signal for the off-K-edge low energy (13.42 keV) and when Co -ray irradiation was employed as the reference. When irradiated at 80K, a much larger exposure (roughly 10 times) of soft X-rays was needed to obtain the same signal intensity as that observed at room temperature. EPR signals were not detectable with g-irradiation at liquid nitrogen temperature.
Yokoya, Akinari; Takakura, Kaoru*; Watanabe, Ritsuko; Akamatsu, Ken*; Ito, Takashi*
Radiation Research, 162(4), p.469 - 473, 2004/10
Times Cited Count：3 Percentile：10.08(Biology)X-ray absorption spectra from single crystals of 5-Bromouracil were measured with the transmission mode in the energy range from 13.41 to 13.50 keV using the linearly polarized synchrotron radiation (SR). A characteristic resonance structure, consisting of four peaks, was recognized in the spectra in the Br K-edge region. The intensities of these peaks were strongly dependent on the crystal rotation about the normal of the crystal b-c plane, which was set perpendicular to the X-ray beam direction. (SR X-rays are polarized in the horizontal plane.) Molecular orbital calculations indicate that these resonance peaks are associated with the transitions from the 1s electron of Br to the Br-C molecular antibonding orbitals and to a shape resonance. The observed anisotropy of each photoabsorption peak might originate from the angular dependences of these molecular orbitals.
Toida, Masaru*; Atsumi, Hiroyuki*; Nagoya, Kaoru*; Suyama, Yasuhiro*
JNC TJ7440 2005-070, 279 Pages, 2004/03
JNC-TJ7440-2005-070.PDF:22.63MB
no abstracts in English
Toida, Masaru*; Atsumi, Hiroyuki*; Nagoya, Kaoru*; Suyama, Yasuhiro*
JNC TJ7400 2005-057, 113 Pages, 2004/03
JNC-TJ7400-2005-057.PDF:20.78MB
In this study, in order to conduct all unsaturated territory investigation techniques in the same test site, and to present the result of estimations which interpolate mutually, the continuous wave radar between the hole, and the pore water pressure measurment near the drift wall were executed, in the NATM gallery.
*; Nakajima, Hayato; Onuki, Kaoru; Ikenoya, Kazuhiko*; Shimizu, Saburo
International Journal of Hydrogen Energy, 24(7), p.603 - 612, 1999/00
Times Cited Count：40 Percentile：81.32(Chemistry, Physical)no abstracts in English
Nakajima, Hayato; Ikenoya, Kazuhiko*; Onuki, Kaoru; Shimizu, Saburo
Kagaku Kogaku Rombunshu, 24(2), p.352 - 355, 1998/00
Times Cited Count：49 Percentile：86.77(Engineering, Chemical)no abstracts in English
Hino, Ryutaro; Suzuki, Kunihiro; Haga, Katsuhiro; Nekoya, Shinichi; Fukaya, Kiyoshi; Shimizu, Saburo; Onuki, Kaoru; Takada, Shoji; Mogi, Haruyoshi; Sudo, Yukio
JAERI-Review 95-016, 115 Pages, 1995/10
no abstracts in English
Kambara, Toyozo; Uno, Hidero; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Takayanagi, Hiroshi; Fujimura, Tsutomu; Morita, Morito; Ichihara, Masahiro; et al.
JAERI 1045, 11 Pages, 1963/03
no abstracts in English
JRR-2 Control Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.
JAERI 1027, 57 Pages, 1962/09
no abstracts in English
