Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sato, Satoshi; Tanaka, Teruya*; Hori, Junichi; Ochiai, Kentaro; Nishitani, Takeo; Muroga, Takeo*
Journal of Nuclear Materials, 329-333(Part2), p.1648 - 1652, 2004/08
Times Cited Count：2 Percentile：16.97(Materials Science, Multidisciplinary)no abstracts in English
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：44.60(Chemistry, Inorganic & Nuclear)no abstracts in English
Matsuda, Norihiro; Nakashima, Hiroshi; Kasugai, Yoshimi; Sasamoto, Nobuo*; Kinno, Masaharu*; Kitami, Takayuki; Ichimura, Takahito; Hori, Junichi*; Ochiai, Kentaro; Nishitani, Takeo
Journal of Nuclear Science and Technology, 41(Suppl.4), p.74 - 77, 2004/03
In high power proton accelerator facilities, concrete shield can be highly activated, which makes maintenance work quite difficult. So, a low-activationized concrete (limestone concrete) is to be partially adopted as a concrete shield for Japan Proton Accelerator Research Complex (J-PARC) aiming at reducing 
-ray exposure dose during maintenance period. A new quantity, 
Na-equivalent, was introduced as a criterion to assure effectiveness of the low-activationized concrete. In order of its verification, powdered low-activationized concrete and ordinary one were irradiated using FNS at JAERI. The measurements were analyzed by a shielding design code system being used for J-PARC, showing that the calculations reproduce the measured induced activity within a factor of 2. Furthermore, by using the same code system, -ray exposure dose was calculated for the configuration of J-PARC to find out that -ray exposure dose by the low-activationized concrete was about 10 times lower than that by the ordinary concrete in a period of less than a few days after operation.
Sato, Satoshi; Morioka, Atsuhiko; Kinno, Masaharu*; Ochiai, Kentaro; Hori, Junichi; Nishitani, Takeo
Journal of Nuclear Science and Technology, 41(Suppl.4), p.66 - 69, 2004/03
no abstracts in English
Kai, Tetsuya; Harada, Masahide; Maekawa, Fujio; Teshigawara, Makoto; Konno, Chikara; Ikeda, Yujiro
Journal of Nuclear Science and Technology, 41(Suppl.4), p.172 - 175, 2004/03
In J-PARC neutron source, intense protons (3 GeV,1 MW) pass through a proton-beam window and bombard a Hg target in a target-moderator-reflector-assembly (TMRA). The SS316 target chamber is the most highly activated. Decouplers (Ag-In-Cd (AIC) alloy) are also highly activated. Some neutron extraction holes of Be and AL-coated iron reflector are lined with AIC alloy. A SS316 shield is located outer the TMRA. All these components are cooled by H
O or DO. We estimated the induced-radioactivity of the TMRA components and the cooling water using NMTC/JAM, MCNP4 and DCHAIN-SP. As results, the remote maintenance and massive shields were indispensable. For example, a 30 cm thick Fe cask for the reflector assembly was necessary to attenuate the radiation less than 1 mSv/h. The cask required a 130-ton crane. The AL-coated Fe of the reflector was adopted instead of SS316 resulting in eliminating the high activity of Ni in SS316 and reduction of the cask weight. Based on these results, shielding wall designs and maintenance scenarios of the highly activated components are developed.
Kasugai, Yoshimi; Kai, Tetsuya; Maekawa, Fujio; Nakashima, Hiroshi; Takada, Hiroshi; Konno, Chikara; Numajiri, Masaharu*; Ino, Takashi*; Takahashi, Kazutoshi*
JAERI-Research 2003-034, 115 Pages, 2004/01
JAERI-Research-2003-034.pdf:4.18MB
Measurement of radioactivity induced by high-energy protons with energy of 2.83 and 24 GeV and spallation neutrons produced by bombarding a mercury target with the high-energy protons were performed by using the AGS (Alternative Gradient Synchrotron) accelerator at Brookhaven National Laboratory. The samples of boron, carbon, aluminum, iron, copper, niobium, mercury-oxide, lead, bismuth, acrylic resin, SS-316, Inconel-625 and Inconel-718 were irradiated around the mercury target. After the irradiation, the radioactivity of each sample was measured by using HPGe detectors at the cooling time between 2 h and 200 d. In the processing of the measured -ray spectra, more than 90 radioactive nucleus were identified, and the radioactivity data were obtained. This report gives the experimental procedure, the data processing and the experimental results in detail.
Miyamoto, Yukihiro
Hokeikyo Nyusu, (32), p.2 - 3, 2003/10
no abstracts in English
Kai, Tetsuya; Maekawa, Fujio; Kasugai, Yoshimi; Niita, Koji*; Takada, Hiroshi; Meigo, Shinichiro; Ikeda, Yujiro
Proceedings of ICANS-XVI, Volume 3, p.1041 - 1049, 2003/07
A radioactivity calculation code system DCHAIN-SP was validated in view of the following points: (1) Activation cross section data library for the energy region below 20 MeV. (2) NMTC/JAM code for calculation of the nuclide yield induced by the high energy particles above 20 MeV. (3) DCHAIN-SP code system which treats overall nuclide yield by the high energy particles. 42 of activation cross sections and 22 tritium production cross sections were revised so that the DCHAIN-SP calculation could improve its accuracy within 30% for typical materials irradiated by 14-MeV neutrons. The NMTC/JAM code was improved to implement the GEM model for better estimation of light fragment production. Accuracy of the nuclide yield for proton induced reactions in 10 MeV - 10 GeV still remains in the level of a factor of 2 to 3. The DCHAIN-SP code system was employed for the analysis of time evolution of the radioactivity produced in the samples on a thick mercury target bombarded with 2.83 and 24 GeV protons. It is found that the code system agrees with the measured data by a factor of 2 to 3.
Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori*; Harada, Yasunori
JAERI-Tech 2002-086, 43 Pages, 2002/11
Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics.
Endo, Akira; Noguchi, Hiroshi; Tanaka, Susumu; Kanda, Yukio*; Oki, Yuichi*; Iida, Takao*; Sato, Kaoru; Tsuda, Shuichi
Applied Radiation and Isotopes, 56(4), p.615 - 620, 2002/04
Times Cited Count：3 Percentile：22.96(Chemistry, Inorganic & Nuclear)Formation mechanism and size distribution of radioactive aerosol particles generated in a high-energy neutron field were studied in order to evaluate a particle size parameter for internal dose evaluation in high-energy accelerator facilities. Argon gas containing DOP aerosols was irradiated by a 65MeV quasi-monoenergetic neutron beam of TIARA. The number size distribution of the DOP aerosols and the activity-weighted size distribution of 
Cl and 
Cl aerosols, formed from the (n, 2np) and (n, np) reactions of 
Ar, were measured using an electrical low-pressure impactor. The activity-weighted size distribution of the radioactive aerosols was well explained by the simple attachment model of the radioactive atoms to the DOP aerosols.
Kai, Tetsuya; Maekawa, Fujio; Kasugai, Yoshimi; Kosako, Kazuaki*; Takada, Hiroshi; Ikeda, Yujiro
JAERI-Research 2002-005, 65 Pages, 2002/03
JAERI-Research-2002-005.pdf:2.75MB
Reliability assessment for the High Energy Particle Induced Radioactivity Calculation Code DCHAIN-SP 2001 was carried out through analysis of integral activation experiments with 14-MeV neutrons. The following three series of experiments conducted at the D-T neutron source facility, FNS, in JAERI were employed: (1) the decay gamma-ray measurement experiment for fusion reactor materials, (2) the decay heat measurement experiment for 32 fusion reactor materials, and (3) the integral activation experiment on mercury.As a result, it was found that the calculations with DCHAIN-SP 2001 predicted the experimental data for (1)
(3) approximately within 30%, 20% and 20%, respectively. It was concluded that the activation cross section data below 20 MeV and the associated decay data as well as the calculation algorithm for solving the Beteman equation that was the master equation of DCHAIN-SP were adequate.
Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi; Hosono, Masakazu; Watanabe, Hiromasa; Yamano, Naoki*
Journal of Nuclear Science and Technology, 37(Suppl.1), p.840 - 844, 2000/03
no abstracts in English
Miyamoto, Yukihiro; ; Harada, Yasunori
JAERI-Tech 98-039, 44 Pages, 1998/09
no abstracts in English
; Fukuda, Mitsuhiro; ; Watanabe, Hiromasa; Yamano, Naoki*
JAERI-Data/Code 97-019, 91 Pages, 1997/05
JAERI-Data-Code-97-019.pdf:2.58MB
no abstracts in English
Seki, Yasushi; Aoki, Isao; Yamano, Naoki*; Tabara, Takashi*
Fusion Technology, 30(3), p.1624 - 1629, 1996/12
no abstracts in English
; Seki, Yasushi; Sato, Satoshi;
Purazuma, Kaku Yugo Gakkai-Shi, 71(10), p.987 - 1001, 1995/10
no abstracts in English
V, 
Co, and 
Zn via the (p,n) sequential reaction processes in titanium, iron, and copper metals associated with 14-MeV neutron irradiationIkeda, Yujiro; Konno, Chikara; Maekawa, Hiroshi
Nuclear Science and Engineering, 116, p.19 - 27, 1994/01
Times Cited Count：6 Percentile：52.02(Nuclear Science & Technology)no abstracts in English
Maekawa, Hiroshi
Proc. of the 8th Int. Conf. on Radiation Shielding, 0, p.15 - 24, 1994/00
no abstracts in English
Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi; Yokota, Wataru; Kamiya, Tomihiro; Watanabe, Hiromasa; Yamano, Naoki*; ;
Proc. of the 8th Int. Conf. on Radiation Shielding, 0, p.965 - 971, 1994/00
no abstracts in English
S.Zimin*; Takatsu, Hideyuki; Mori, Seiji*; ; Seki, Yasushi; Sato, Satoshi; Tada, Eisuke
JAERI-M 93-141, 75 Pages, 1993/07
no abstracts in English
