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Nakashima, Hiroshi
JAEA-Conf 2020-001, p.69 - 74, 2020/12
J-PARC (Japan Proton Accelerator Research Complex) is a high-energy proton accelerator complex of the world's highest beam power. Because of its very high beam power and its high energy as well as the large-scale accelerator complex, we encountered some very difficult problems on radiation safety design. Various examinations and countermeasures were considered in order to overcome the difficulty. This paper introduces some of them. In addition, some new knowledge obtained during 10 years after completion are described.
Suganuma, Kazuaki; Hiroki, Fumio; Ito, Takashi; Yamazaki, Yoshio
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.846 - 848, 2019/07
In the past, water flow decreased at water cooling system in J-PARC Linac. Contamination get mixed in cooling water. The problem was resolved by changing the system of the circulation pumps and reducing the tiny metal in water cooling system. However, suppression of occurring tiny metal is unresolved. The tiny metal is the unique problem of accelerator. It is caused by heavy using oxygen free copper and phosphorus deoxidized copper. The two copper is used for the part of accelerator and purified water. The object of the report is investigation of tiny metal contamination of water cooling system in J-PARC Linac.
Harada, Hiroyuki; Saha, P. K.; Kinsho, Michikazu
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.179 - 182, 2019/07
Recently, humankind had big discovery about neutron star, which is great big nuclear in the space. They are discovery of neutron star with twice mass of solar in 2010 and observation of gravity wave when two neutron start incorporate in 2017. In order to understand the high dense matter like the neutron star, project of experimental researches by using accelerated heavy ion beams become heated in the world, such RHIC-BES-II program, FAIR project, NICA project, etc. The J-PARC provides MW class high intensity proton beams to many experiments and researches. We have study of the heavy ion beam in J-PARC to fully utilize high intensity ability of J-PARC. We propose the accelerator scheme of the beam in J-PARC and the intensity will reach to the world record. In our talk, we will report the current status of proton beam and the accelerator scheme for the high-intensity heavy ion beam in J-PARC.
Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
Journal of Nuclear Science and Technology, 56(5), p.385 - 393, 2019/05
Times Cited Count：3 Percentile：31.36(Nuclear Science & Technology)At high energy accelerator facilities, various radionuclides are produced by nuclear reactions of high energy particles with structure and/or ambient air of the facilities. Consequently, the radionuclides are potential sources of internal exposure for works of the facilities. However, the International Commission on Radiological Protection (ICRP) do not provide dose coefficients, which are committed effective doses per intake, for the short-lived radionuclides whose half-lives are shorter than 10 minutes in accordance with the ICRP 2007 Recommendations. Then, we estimated the dose coefficients for inhalation and ingestion of these short-lived radionuclides in accordance with the ICRP 2007 Recommendations. In addition, we compared the dose coefficients with those in accordance with the ICRP 1990 Recommendations. As a result, a decreasing tendency was shown in the dose coefficients for inhalation cases; an increasing tendency was observed in those for ingestion cases. It was found that these changes in dose coefficients were mainly caused by the revision of the dose calculation procedures, alimentary tract models. The result of this study will be useful for planning of radiation protection at the high energy facilities.
Kamikubota, Norihiko*; Yamada, Shuei*; Sato, Kenichiro*; Kikuzawa, Nobuhiro; Yamamoto, Noboru*; Yoshida, Susumu*; Nemoto, Hiroyuki*
Proceedings of 16th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2017) (Internet), p.1470 - 1473, 2018/01
no abstracts in English
Andreyev, A. N.; Nishio, Katsuhisa; Schmidt, K.-H.*
Reports on Progress in Physics, 81(1), p.016301_1 - 016301_61, 2018/01
Times Cited Count：127 Percentile：91.67(Physics, Multidisciplinary)Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Sato, Tetsuya; Nagame, Yuichiro; et al.
EPJ Web of Conferences, 163, p.00041_1 - 00041_6, 2017/11
Times Cited Count：1 Percentile：61.03(Nuclear Science & Technology)Kinsho, Michikazu
Proceedings of 6th International Particle Accelerator Conference (IPAC '15) (Internet), p.3798 - 3800, 2015/06
Beam power of routine operation of the J-PARC rapid cycling synchrotron (RCS) increased gradually for the MLF user operation, beam power of 400 kW was achieved on 10th March, and 500 kW user operation has been stably performed from 14th April this year. Beam studies were also performed to demonstrate the capability of the RCS to operate at powers in excess of 1 MW. The study produced a beam intensity of 8.41
10
protons during short time, an intensity equivalent to 1.01 MW operation on 10th January 2015. In this beam study it was cleared issues to realize 1MW operation in the RCS. Status of user operation and issues to realize high power operation in the RCS are presented.
Chishiro, Etsuji; Yamazaki, Masayoshi*; Hori, Toshihiko*; Hasegawa, Kazuo
Proceedings of 28th Linear Accelerator Meeting in Japan, p.303 - 305, 2003/08
no abstracts in English
Kinsho, Michikazu; Saito, Yoshio*; Nishizawa, Daiji*; Michizono, Shinichiro*
Journal of Nuclear Materials, 318, p.307 - 312, 2003/05
Times Cited Count：9 Percentile：53.22(Materials Science, Multidisciplinary)In order to choose an alumina ceramic material for use as a vacuum beam duct in a rapid cycling synchrotron, several kinds of alumina ceramics, having different microstructures, were examined under radiation fields of 2.5 MeV electrons. Since a long ceramic duct can only be manufactured by glazing duct segments, the mechanical strength and deterioration not only a ceramics but also in the glazing joint were measured after irradiation. These ceramic have a sufficiently high flexural strength which is more than 300 MPa before electron beam irradiation, and we could get the experimental results that there was no deterioration on the flexural strength of the ceramic after 1000 MGy electron beam irradiation. No noticeable changes could be seen in the measured tensile strength of Ti-ceramic brazed samples after 1000 MGy electron beam irradiation.
Masukawa, Fumihiro; Nakano, Hideo*; Nakashima, Hiroshi; Sasamoto, Nobuo; Tayama, Ryuichi*; Handa, Hiroyuki*; Hayashi, Katsumi*; Hirayama, Hideo*; Shin, Kazuo*
JAERI-Tech 2003-018, 42 Pages, 2003/03
no abstracts in English
Tsuda, Shuichi; Yamaguchi, Yasuhiro
Hoken Butsuri, 36(1), p.51 - 60, 2001/03
no abstracts in English
Kawai, Katsuo; Endo, Akira
JAERI-Data/Code 2000-033, 59 Pages, 2000/10
JAERI-Data-Code-2000-033.pdf:3.35MB
no abstracts in English
Arakawa, Kazuo
Isotope News, (525), p.57 - 58, 1998/02
no abstracts in English
Endo, Akira; Takada, Hiroshi; Yamaguchi, Yasuhiro
JAERI-Data/Code 97-039, 37 Pages, 1997/10
JAERI-Data-Code-97-039.pdf:1.36MB
no abstracts in English
Sawamura, Sadashi*
PNC TJ1600 97-001, 77 Pages, 1997/03
no abstracts in English
Tanaka, Ryuichi; Yotsumoto, Keiichi; Watanabe, Hiromasa
Radioisotopes, 45(3), p.213 - 220, 1996/03
no abstracts in English
Nihon Kessho Gakkai-Shi, 38(3), p.249 - 253, 1996/00
no abstracts in English
Sawamura, Sadashi*
PNC TJ1600 95-004, 51 Pages, 1995/03
no abstracts in English
Tamada, Masao
Isotope News, (484), p.18 - 21, 1994/10
no abstracts in English
