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Shikaze, Yoshiaki
Journal of Nuclear Science and Technology, 61(7), p.894 - 910, 2024/07
Times Cited Count：2 Percentile：37.43(Nuclear Science & Technology)Among the radioactive nuclides inside the nuclear reactor buildings emitted by the Fukushima Daiichi nuclear reactor accident, high-energy beta-ray sources, such as strontium-90 and yttrium-90, generate bremsstrahlung photons in the building materials, comprising the wall, floor, and interior structure. Therefore, evaluating the radiation dose of the bremsstrahlung to the workers in the nuclear reactor building is crucial for radiation protection. The precision of the evaluation calculation of the bremsstrahlung dose was investigated by comparing the Particle and Heavy Ion Transport code System (PHITS) and the GEometry ANd Tracking (GEANT4) simulation code results. In the calculation, behind various shielding plates (lead, copper, aluminum, glass, and polyethylene, with thicknesses ranging from 1.0 to 40 mm), the water cylinder was set as the evaluated material, the absorbed dose and the deposited energy spectrum by the bremsstrahlung photons were obtained, and the characteristics and differences for both simulation codes were investigated. In the comparison results of the deposited energy spectrum, the spectral shapes have consistent trends. In the energy range below several tens of keV, a peak is seen in the PHITS spectrum for the lead shielding material. In comparing the absorbed dose under various conditions of the shielding plate for generating bremsstrahlung photons, most results for both codes correlate within an 
10% difference for 2.280 MeV beta-ray sources and an 20% difference for 0.5459 MeV beta-ray sources, except for 30% for 20 mm thick lead. Although there were differences in some cases, the evaluation results of the two simulation codes were concluded to correlate well with the above precision.
-rays of fuel debrisMatsumura, Taichi; Okumura, Keisuke; Fujita, Manabu*; Sakamoto, Masahiro; Terashima, Kenichi; Riyana, E. S.
Radiation Physics and Chemistry, 199, p.110298_1 - 110298_8, 2022/10
Times Cited Count：3 Percentile：37.49(Chemistry, Physical)Yokoya, Akinari; Fujii, Kentaro; Ushigome, Takeshi; Shikazono, Naoya; Urushibara, Ayumi; Watanabe, Ritsuko
Radiation Protection Dosimetry, 122(1-4), p.86 - 88, 2006/12
Times Cited Count：13 Percentile：64.16(Environmental Sciences)We have studied yields of DNA damages induced by soft X-rays obtained from a conventional soft X-ray machine in a LET region between -rays and ultrasoft X-rays. Practically soft X-rays with a broad energy spectrum emitted from a target of heavy metal, such as tungsten, have been widely used not only for radiobiological experiments but also for medical application such as mammography. Radiation weighting factors for these soft X-rays have been assigned to be 1 by ICRP. However, the fraction of a large number of low energy photons in the spectrum (below several tens keV) provided by bremsstrahlung is expected to be more effective for DNA damage induction than -rays since low energy photo- and Auger electrons predominantly ejected in consequence of a photoelectric effect can produce dense clusters of ionization/excitation on DNA molecules. We have examined the yield of DNA strand breaks induced by white soft X-rays (150 kVp, tungsten target). Yields of base lesions revealed by base excision repair enzymes will be also presented.
Bakhtiari, M.; Kramer, G. J.*; Takechi, Manabu; Tamai, Hiroshi; Miura, Yukitoshi; Kusama, Yoshinori; Kamada, Yutaka
Physical Review Letters, 94(21), p.215003_1 - 215003_4, 2005/06
Times Cited Count：55 Percentile：85.19(Physics, Multidisciplinary)Bremsstrahlung radiation of runaway electrons is found to be an energy limit for runaway electrons in tokamaks. The minimum and maximum energy of runaway electron beams is shown to be limited by collisions and Bremsstrahlung radiation, respectively. It is also found that a massive injection of a high-Z gas such as Xenon can terminate a disruption-generated runaway current before the runaway electrons hit the walls.
H and 
C induced in concrete shielding of an electron accelerator facilityEndo, Akira; Harada, Yasunori; Kawasaki, Katsuya; Kikuchi, Masamitsu
Applied Radiation and Isotopes, 60(6), p.955 - 958, 2004/06
Times Cited Count：7 Percentile：43.85(Chemistry, Inorganic & Nuclear)no abstracts in English
Mehta, K.*; Kojima, Takuji; Sunaga, Hiromi
Radiation Physics and Chemistry, 68(6), p.959 - 962, 2003/12
Times Cited Count：3 Percentile：25.12(Chemistry, Physical)Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters:ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 -ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement of better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.
spatial profile from background light in incoherent Thomson scattering diagnosticNaito, Osamu; Hatae, Takaki
JAERI-Research 2002-033, 9 Pages, 2003/03
JAERI-Research-2002-033.pdf:0.46MB
A simulation study on the feasibility of inferring spatial profile along with electron temperature and density in Thomson scattering diagnostic is presented. The background signal, which is usually discarded after subtracted from the Thomson scattered signal, is used in the reconstruction procedure. If the contribution from line radiation to the background signal is by one order of magnitude smaller than that from bremsstrahlung, a fairly accurate profile can be reconstructed.
Nishio, Satoshi; Tobita, Kenji; Ushigusa, Kenkichi; Konishi, Satoshi
Purazuma, Kaku Yugo Gakkai-Shi, 78(11), p.1218 - 1230, 2002/11
no abstracts in English
Bi at intermediate energiesHaba, Hiromitsu; Kasaoka, Makoto*; Igarashi, Manabu*; Washiyama, Koshin*; Matsumura, Hiroshi*; Oura, Yasuji*; Shibata, Seiichi*; Sakamoto, Ko*; Furukawa, Michiaki*; Fujiwara, Ichiro*
Radiochimica Acta, 90(7), p.371 - 382, 2002/08
Times Cited Count：2 Percentile：16.11(Chemistry, Inorganic & Nuclear)The reaction yields of 63 radionuclides with the mass number A = 56-135 produced in the photofission of Bi by bremsstrahlung of end-point energies (E
) from 450 to 1100 MeV have been measured using a catcher foil technique. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Z
) expressed by Z = RA + S, and with the A-independent FWHME
. The charge distribution parameters R, S and FWHM were independent of E above 600 MeV. The weighted mean values at E 
600 MeV were R = 0.421 
0.001, S = 0.6 0.1 and FWHM = 2.1 0.1 charge unit (c.u.). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable mass A of 96 1 mass unit (m.u.) and the width FWHM
of 33 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for 
Au based on the results of calculations using PICA3/GEM.
Enoeda, Mikio; Ohara, Yoshihiro; Akiba, Masato; Sato, Satoshi; Hatano, Toshihisa; Kosaku, Yasuo; Kuroda, Toshimasa*; Kikuchi, Shigeto*; Yanagi, Yoshihiko*; Konishi, Satoshi; et al.
JAERI-Tech 2001-078, 120 Pages, 2001/12
This report is a summary of the design works, which was discussed in the design workshop held in 2000 for the demonstration (DEMO) blanket aimed to strengthen the commercial competitiveness and technical feasibility simultaneously. The DEMO blanket must supply the feasibility and experience of the total design of the power plant and the materials. This conceptual design study was performed to determine the updated strategy and goal of the R&D of the DEMO blanket which applies the supercritical water cooling proposed in A-SSTR, taking into account the recent progress of the plasma research and reactor engineering technology.
Asano, Yoshihiro
Advanced Photon Source International Workshop on Radiation Safety at Synchrotron Radiation Sources, p.1 - 7, 2001/04
no abstracts in English
Nishio, Satoshi; Ushigusa, Kenkichi; Ueda, Shuzo; Polevoi, A.*; Kurita, Genichi; Tobita, Kenji; Kurihara, Ryoichi; Hu, G.; Okada, Hidetoshi*; Murakami, Yoshiki*; et al.
JAERI-Research 2000-029, 105 Pages, 2000/10
JAERI-Research-2000-029.pdf:4.19MB
no abstracts in English
Kojima, Takuji; Sunaga, Hiromi; Tachibana, Hiroyuki; Takizawa, Haruki; Tanaka, Ryuichi
IAEA-TECDOC-156, p.91 - 98, 2000/06
no abstracts in English
Kurihara, Ryoichi; Nishio, Satoshi; Ueda, Shuzo; Polevoi, A. R.; Aoki, Isao; Ajima, Toshio*; Okada, Hidetoshi*; Hasegawa, Mitsuru*; Ushigusa, Kenkichi
Journal of Plasma and Fusion Research SERIES, Vol.3, p.553 - 557, 2000/00
no abstracts in English
Seki, Yasushi
New Energy Systems and Conversions, p.355 - 359, 1999/00
no abstracts in English
Yamagiwa, Mitsuru; Koga, J. K.; Sagisaka, Akito*; Nagashima, Keisuke
Plasma Physics and Controlled Fusion, 41(2), p.265 - 270, 1999/00
Times Cited Count：2 Percentile：8.74(Physics, Fluids & Plasmas)no abstracts in English
Kikuchi, Mitsuru
Purazuma, Kaku Yugo Gakkai-Shi, 74(9), p.944 - 946, 1998/09
no abstracts in English
superconductor application to magnets for tokamak fusion reactorsAndo, Toshinari; Isono, Takaaki; Nakajima, Hideo; Kikuchi, Mitsuru; Tsuji, Hiroshi
Fusion Technology 1998, p.791 - 794, 1998/00
no abstracts in English
Furuya, Kazuyuki; Enoeda, Mikio; Hatano, Toshihisa; Sato, Satoshi; Kuroda, Toshimasa*; Takatsu, Hideyuki
Journal of Nuclear Materials, 258-263, p.2023 - 2029, 1998/00
Times Cited Count：13 Percentile：70.08(Materials Science, Multidisciplinary)no abstracts in English
Minehara, Eisuke;
Proc. of 11th Symp. on Accelerator Sci. and Technol., P. 119, 1997/00
no abstracts in English
