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Nii, Keisuke*; Ida, Yoshiaki*; Ueda, Hideki*; Yamaguchi, Takanori*; Kabumoto, Hiroshi; Kamiya, Junichiro; Kondo, Yasuhiro; Tamura, Jun; Harada, Hiroyuki; Matsui, Yutaka; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.601 - 604, 2023/01
no abstracts in English
Nii, Keisuke*; Ida, Yoshiaki*; Ueda, Hideki*; Yamaguchi, Takanori*; Kabumoto, Hiroshi; Kamiya, Junichiro; Kondo, Yasuhiro; Tamura, Jun; Harada, Hiroyuki; Matsui, Yutaka; et al.
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.334 - 337, 2021/10
no abstracts in English
Hirayama, Hideo*; Nakashima, Hiroshi; Sanami, Toshiya*; Yamaguchi, Yasuhiro; Sato, Osamu*; Takagi, Shunji*; Suzuki, Toshikazu*; Iwai, Satoshi*
Nihon Genshiryoku Gakkai-Shi ATOMO
, 55(2), p.83 - 96, 2013/02
Since the accident at the Fukushima Daiichi Power Plant, units of radiation doses such as Sv have been frequently reported by newspapers. However, it is not exactly understood even by experts on nuclear engineering that there are two different concepts which are the protection quantity such as the effective dose related to a radiation health risk and the practical quantity such as ambient dose equivalents related to measurements. In this special issue, Radiological Protection Quantity, and Operational Quantity and Radiological Protection Quantity, explain the radiation protection dose system including the protection and practical quantities established by ICRP and ICRU. Relation between Dosimeters used at Fukushima etc. and Radiological Protection Quantity describes a method and its problems to measure radiations from Cs on surface and underground using survey meters and personal dosimeters, and convert the measured values to effective doses.
Yamaguchi, Yasuhiro
Senmon Toshokan, (256), p.25 - 28, 2012/11
The Japan Health Physics Society addresses the issues of radiation protection for uses of nuclear energy, radiation and radioactive materials in a varaity of fields and issues quarterly the Japanese Journal of Health Physics. The Journal contains scientific papers, reports and news, recently articles about the effects of the Fukushima nuclear accident. People have a great interest in the radiation protection issues due to the accident. This article presents the editorial work of the Journal.
Yamaguchi, Yasuhiro
Iryo Hoshasen Bogo Newsletter, (59), p.5 - 8, 2010/12
International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) has being revised and its draft 4.0 was opened for comment. The manuscript describes the outline of the BSS draft 4.0, its role in the system of IAEA safety standard and major points of the revision.
Yamaguchi, Yasuhiro
Hokeikyo Nyusu, (46), P. 17, 2010/10
At the 30th anniversary of the Institute of Radiation Measurements, a praise should be given to the Institute for its great contribution to the safe development of nuclear and radiological technology in Japan. Two significant contributions should be pointed out. One is the quality improvement of radiation measurement instruments in nuclear power stations applying techniques developed by JAEA, and the other is the enlightement of radiation knowledge over the society using user-friendly radiation meters.
Hasegawa, Kazuo; Morishita, Takatoshi; Kondo, Yasuhiro; Oguri, Hidetomo; Kobayashi, Tetsuya; Naito, Fujio*; Yoshioka, Masakazu*; Matsumoto, Hiroshi*; Kawamata, Hiroshi*; Hori, Yoichiro*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.693 - 695, 2010/03
The J-PARC RFQ (length 3.1m, 4-vane type, 324 MHz) accelerates a beam from the ion source to the DTL. The beam test of the linac was started in November 2006 and 181 MeV beam was successfully accelerated in January 2007. Since then, the linac has been delivered beams for commissioning of the linac itself, downstream accelerators and facilities. Trip rates of the RFQ, however, suddenly increased in Autumn 2008, and we are suffering from this issue for user run operation. We tried to recover by tender conditioning, modification of RF control, improvement of vacuum and so on. We manage to have beam operation. In this report, we describe the status of the RFQ.
Hasegawa, Kazuo; Asano, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; Ito, Takashi; Kobayashi, Tetsuya; Kondo, Yasuhiro; Namekawa, Yuya; Oguri, Hidetomo; Okoshi, Kiyonori; et al.
Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.55 - 57, 2009/00
The beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac has delivered beams to the 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, the subsequent Main Ring Synchrotron and the neutron target commissioning. The linac uses a Cs-free LaB
-driven ion source and 20 units of 324 MHz klystrons. As of June 2008, the operation times are about 3,000 and 6,000 hours for the ion source and the RF source, respectively. The operating experience of the linac is described.
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Shimizu, Shigeru; Yoshizawa, Michio; Yamaguchi, Yasuhiro
Journal of Nuclear Science and Technology, 45(Suppl.5), p.209 - 212, 2008/06
Times Cited Count：8 Percentile：49.01(Nuclear Science & Technology)The neutron calibration fields is necessary to evaluate the energy response of the neutron monitors and dosimeters used in the facility such as J-PARC. The neutron calibration fields using accelerators, for the purpose, have been developed at the Facility of Radiation Standards (FRS) of JAEA-Tokai for neutrons below 20MeV and at Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) of JAEA-Takasaki for those over 20 MeV. At FRS, a 4 MV Van-de-Graaff (Pelletron) accelerator is used. Up until the present, developments of the 8, 144, 250, 565 keV, 5.0 and 14.8 MeV fields have been completed. At TIARA, an AVF cyclotron is used, and three neutron fields of 45, 60 and 75 MeV are planned to be established. For the development, evaluation of the characteristics of the field have been in process.
O moderated 
Cf source at JAEA and KAERIKowatari, Munehiko; Fujii, Katsutoshi; Tsutsumi, Masahiro; Kim, B.-H.*; Lee, K.-C.*; Yoshizawa, Michio; Yamaguchi, Yasuhiro
Journal of Nuclear Science and Technology, 45(Suppl.5), p.217 - 220, 2008/06
Times Cited Count：1 Percentile：10.05(Nuclear Science & Technology)no abstracts in English
Tsuda, Shuichi; Nakane, Yoshihiro; Yamaguchi, Yasuhiro
Radiation Protection Dosimetry, 126(1-4), p.174 - 177, 2007/08
Times Cited Count：6 Percentile：42.5(Environmental Sciences)no abstracts in English
Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira; Yamaguchi, Yasuhiro
Radiation Protection Dosimetry, 126(1-4), p.501 - 505, 2007/08
Times Cited Count：4 Percentile：31.41(Environmental Sciences)A new inventive radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with WIde energy raNges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high energy accelerator facilities. DARWIN satisfies the following features: (1) capable of monitoring doses from neutrons, photons and muons with wide energy ranges - from thermal energy to 1 GeV, 150 keV to 100 MeV, and 1 MeV to 100 GeV, respectively, (2) high sensitivity and precision - more than 10 times as sensitive as conventional moderator-based survey instruments for neutrons, (3) easy to operate with a simple user-interface, and (4) light weighted for movability. The details of the features will be described at the presentation, together with the results of the calibrations performed in several accelerator facilities.
O-moderated Cf sourceKowatari, Munehiko; Fujii, Katsutoshi; Takahashi, Masa; Yoshizawa, Michio; Shimizu, Shigeru; Kawasaki, Katsuya; Yamaguchi, Yasuhiro
Radiation Protection Dosimetry, 126(1-4), p.138 - 144, 2007/08
Times Cited Count：5 Percentile：37.19(Environmental Sciences)The facility of the Radiation Standards (FRS) of the Japan Atomic Energy Agency was equipped with the reference neutron field by using DO moderated Cf neutron source (DO-Cf), with a 30cm diameter DO sphere. In order to determine the characteristics of the reference field within the ranges of calibration distance (75 to 200 cm from the center of the source to the calibration point) in detail, the authors performed the evaluation of the neutron spectra and neutron fluence rate at various distances from the DO moderated source assembly by computations using MCNP-4C and by experimental studies using Bonner Multi-sphere neutron Spectrometer (BMS). Due to the volume neutron source, it is difficult to measure the contribution of the scattered neutron component with the desirable accuracy by shadow-cone method. In this study, the net counting rate of each counter of BMS was corrected by estimating the ratio of the counting rate of each counter in condition of the experimental and the ideal arrangement by the Monte Carlo calculation. The spectra of the direct component were unfolded by using the corrected counting rate with SAND II code. The averaged dose conversion coefficients (h
(10) and h
(10)) and neutron dose rates (H(10) and H(10)) at various distance were estimated based on the measured spectra. The effectiveness of the correction was discussed by comparing the measured and calculated values. Additionally, the suitable distance for the calibration of personal dosimeter at FRS reference field was evaluated by the results.
Shikaze, Yoshiaki; Tanimura, Yoshihiko; Saegusa, Jun; Tsutsumi, Masahiro; Yamaguchi, Yasuhiro; Uchida, Yoshiaki*
Radiation Protection Dosimetry, 126(1-4), p.163 - 167, 2007/08
Times Cited Count：3 Percentile：25.51(Environmental Sciences)For neutron energy more than 20 MeV, the international standard of the calibration fields and techniques has not been established. Therefore, by using the quasi-monoenergetic neutron irradiation field of 40-90 MeV at TIARA of JAEA Takasaki, we are developing the calibration field. Here we evaluated the properties of the neutron field, where neutrons were produced in the nuclear reaction of the Li target with 45, 50 and 70 MeV protons. We investigated the neutron beam profile at different distance from the target by using the imaging plates with a polyethylene converter to measure the recoil protons produced in the converter. From the results, properties of the neutron beam profile were found as follows: (1) Irradiation field area was fixed geometrically by the distance from the target and the diameter of the collimator exit; (2) The beam intensity within the irradiation field was in inverse proportion to the square of the distance from the target. Also, we measured the peak energy and energy spectrum of neutron through TOF method by using organic liquid scintillation detector. Then we evaluated the energy spectra of the scattered neutrons at various positions outside the irradiation field through unfolding method. The FORIST unfolding code and the response of SCINFUL-QMD code were used here. From the neutron energy spectra obtained in the different method mentioned above, peak fluence for on-beam position was evaluated comparing with the results in previous evaluation of the neutron field at TIARA.
Murakami, Hiroyuki; Mizushita, Seiichi; Yoshizawa, Michio; Yamamoto, Hideaki; Yamaguchi, Takenori; Yamaguchi, Yasuhiro
JAEA-Review 2006-032, 181 Pages, 2006/11
JAEA-Review-2006-032.pdf:45.0MB
This annual report describes the activities of Department of Radiation Protection in Nuclear Science Research Institute in the fiscal year 2005. The report covers environmental monitoring around the facilities, radiation protection of workplace and workers, individual monitoring, maintenance of monitoring instruments, and research and development of radiation protection technologies, which were performed at Nuclear Science Research Institute, Tokai Research and Development Center, Japan Atomic Energy Agency. There were no occupational or public exposures exceeding the prescribed dose limits. No effluent releases were recorded exceeding the prescribed limits on the amount and concentration of radioactivity for gaseous release and liquid waste. As for the research and development activities, studies were conducted focusing mainly on the following themes: technological developments on operational radiation protection and establishment of calibration fields for various types of neutrons.
Saegusa, Jun; Shimizu, Shigeru; Yamaguchi, Yasuhiro; Kim, B.-H.*
Proceedings of 2006 Autumn Conference of the Korean Association for Radiation Protection, p.238 - 239, 2006/11
At the Nuclear Science Research Institute (NSRI) of Japan Atomic Energy Agency (JAEA), reference calibration fields of X-, 
-, 
-rays and neutrons have been provided in the Facility of Radiation Standards (FRS) for calibrating dosemeters used for radiation protection purpose. In this paper we overview these calibration fields and describe its position in the traceability and quality assurance system, present status of their utilization, and so forth.
Yamaguchi, Yasuhiro
Hoeikyo Nyusu, (49), p.11 - 13, 2006/10
"3rd Asian Regional Conference on the Evolution of the System of Radiological Protection" organized by OECD/NEA was held in July in Tokyo. The participants discussed the draft of the ICRP new recommendations opened last June and delivered their comments and opinions directly to the chair of ICRP. This describes the outline of the conference and some points of discussion.
Sato, Tatsuhiko; Niita, Koji*; Iwase, Hiroshi*; Nakashima, Hiroshi; Yamaguchi, Yasuhiro; Sihver, L.*
Radiation Measurements, 41(9-10), p.1142 - 1146, 2006/10
Times Cited Count：30 Percentile：87.57(Nuclear Science & Technology)The applicability of PHITS to the shielding design of spacecrafts was examined by comparing calculated neutron spectra and doses for astronauts in the Space Shuttle with the corresponding experimental data. The agreements between the data were quite satisfactory, especially for the neutron spectra, which have been barely reproduced by other studies. We therefore concluded that PHITS has a great possibility of playing an important role in the design study of spacecrafts.
Takahashi, Fumiaki; Endo, Akira; Yamaguchi, Yasuhiro; Oda, Keiji*
Hoken Butsuri, 41(3), p.180 - 187, 2006/09
no abstracts in English
Yamaguchi, Yasuhiro
Hoshasen Kagaku, 49(9), p.311 - 319, 2006/09
It describes dose conversion coefficients for photon, electron and neutron which are included in ICRP Publication 74. It also describes the background and fundamental knowledges to understand these coefficients.
