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Journal Articles

Development of a function calculating internal dose coefficients based on ICRP 2007 Recommendations

Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

BIO Web of Conferences (Internet), 14, p.03011_1 - 03011_2, 2019/05

Dose coefficients, which are committed effective dose per unit intake of radionuclides, are fundamental amounts for dose estimation and protection standards against internal exposures. In this study, we built a calculation function of dose coefficients using the latest dosimetric models and data as a part of development of internal dosimetry code in accordance with 2007 Recommendations of the International Commission of Radiological Protection (ICRP). Quality of the function was assured by comparing the results generated by the function to values recorded in a database of dose coefficients for workers provided by ICRP. In the presentation, we will report the results of quality assurance and the future plans of code development.

Journal Articles

Estimating internal dose coefficients of short-lived radionuclides in accordance with ICRP 2007 Recommendations

Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

Journal of Nuclear Science and Technology, 56(5), p.385 - 393, 2019/05

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.

Journal Articles

Construction of adult Japanese voxel phantoms with various body sizes and their applications to evaluation of organ doses due to external photon irradiation

Sato, Kaoru; Takahashi, Fumiaki

Hoken Butsuri, 52(4), p.247 - 258, 2017/12

Organ doses for dose assessment in radiation protection are derived from ICRP reference phantoms (Male:RCP-AM, Female:RCP-AF) with standard Caucasian physiques. In adult, Japanese are smaller than Caucasian. To study impact of differences in physiques between Caucasian and Japanese on organ doses, we previously constructed Japanese phantoms (Male:JM-103, Female:JF-103) with average adult Japanese physiques. In addition, adult Japanese physiques have also wide distribution. Thus, we newly modeled DJM (Male) and DJF (Female) with 8 physiques by changing the perimeters of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV, it was found that doses of breast, colon, lung, stomach, gonad, urinary bladder, esophagus, liver and thyroid in DJM and DJF with physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10%.

JAEA Reports

Assessment of specific absorbed fractions for photons and electrons using average adult Japanese female phantom

Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

JAEA-Data/Code 2016-013, 48 Pages, 2016/12

JAEA-Data-Code-2016-013.pdf:1.3MB
JAEA-Data-Code-2016-013-appendix(CD-ROM).zip:0.47MB

In the 2007 Recommendations of the International Commission on Radiological Protection (ICRP), an effective dose is defined as a sum of equivalent doses which are calculated by using male and female reference phantoms based on Caucasian physiological data and averaged over the sexes by tissue weighting factors. Specific absorbed fractions (SAFs), which are essential for internal dosimetry, depend on the body weight and organ masses of phantoms. Then, the dose coefficients, which are committed effective doses per unit intake of radionuclides, developed by ICRP on the basis of the 2007 Recommendations reflect the physical characteristics of Caucasians and are averaged over the sexes. Meanwhile, the physiques of adult Japanese are generally smaller than those of adult Caucasians, and organ masses are also different from each other. Knowledge of the influence of race differences on dose coefficients is important to apply the sex averaged dose coefficients of ICRP to the Japanese system of radiation protection. In this study, SAFs for 25 kinds of mono-energetic electrons and photons ranging from 10 keV to 10 MeV were calculated about the combinations of 67 source regions and 42 target organs using the average adult Japanese female phantom, JF-103, incorporated with a general purpose radiation transport code, MCNPX 2.6.0. The data of this report and the previously published data of JM-103 are applicable to evaluate sex-specific and sex-averaged dose coefficients reflecting the physical characteristics of the average adult Japanese for intakes of all radionuclides not to emit other than photons and electrons.

Journal Articles

Numerical analysis of organ doses delivered during computed tomography examinations using Japanese adult phantoms with the WAZA-ARI dosimetry system

Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji*; Ban, Nobuhiko*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Kai, Michiaki*

Health Physics, 109(2), p.104 - 112, 2015/08

 Times Cited Count:4 Percentile:43.49(Environmental Sciences)

A dosimetry system, named WAZA-ARI, is developed to assess accurately radiation doses to persons from Computed Tomography (CT) examination patients in Japan. Organ doses were prepared to application to dose calculations in WAZA-ARI by numerical analyses using average adult Japanese human models with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the radiation configuration on the table for some multi-detector row CT (MDCT) devices. Then, a source model in PHITS could specifically take into account for emissions of X-ray in each MDCT device based on the experiment results. Numerical analyses with PHITS revealed a concordance of organ doses with human body size. The organ doses by the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculation in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model. The results implied that analyses using the Japanese phantoms and PHITS including source models can appropriately give organ dose data with consideration of the MDCT device and physiques of typical Japanese adults.

Journal Articles

Measurement of air dose rates over a wide area around the Fukushima Dai-ichi Nuclear Power Plant through a series of car-borne surveys

Ando, Masaki; Nakahara, Yukio; Tsuda, Shuichi; Yoshida, Tadayoshi; Matsuda, Norihiro; Takahashi, Fumiaki; Mikami, Satoshi; Kinouchi, Nobuyuki; Sato, Tetsuro*; Tanigaki, Minoru*; et al.

Journal of Environmental Radioactivity, 139, p.266 - 280, 2015/01

 Times Cited Count:24 Percentile:14.05(Environmental Sciences)

A series of car-borne surveys using the KURAMA and KURAMA-II systems was conducted in a wide area in eastern Japan from June 2011 to December 2012 to evaluate the distribution of air dose rates around the Fukushima Dai-ichi Nuclear Power Plant, and to determine the time-dependent trend of decrease in air dose rates. An automated data processing system was established, which enables analyses of large amounts of data obtained with the use of about 100 units of the measurement system in a short time. The initial data for studying the migration status of radioactive cesium was obtained in the first survey, followed by the other car-borne surveys having wider measurement ranges. Comparing the measured air dose rates obtained in each survey, it was found that the decreasing trend of air dose rates measured through car-borne surveys was larger than that expected from the physical decay of radioactive cesium and that measured using NaI (Tl) survey meters around the road.

Journal Articles

WAZA-ARI; A Dose assessment system for patients in CT scan

Sato, Kaoru; Takahashi, Fumiaki; Endo, Akira; Ono, Koji*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Ban, Nobuhiko*; Kai, Michiaki*

RIST News, (58), p.25 - 32, 2015/01

The Japan Atomic Energy Agency (JAEA) are now developing WAZA-ARI for improvement of management of exposure doses due to CT examination under the joint research with the Oita University of Nursing and Health Sciences. The trial version of WAZA-ARI has been released on 21 December 2012. In trial version, users can perform dose assessment by using organ dose database based on the average adult Japanese male (JM-103) and female (JF-103) voxel phantoms and a 4 years old female voxel phantom (UFF4). The homepage of WAZA-ARI has been accessed over 1000 times per month and 28421 times by the end of September 2014. We are developing WAZA-ARI version 2 as the extension version of dose calculation functions of WAZA-ARI. WAZA-ARI version 2 will be released by the end of March 2015. In WAZA-ARI version 2. Users can upload dose calculation results to WAZA-ARI version 2 server, and utilize improvement of the dose management of patients and the optimization of CT scan conditions.

JAEA Reports

Assessment of specific absorbed fractions for photons and electrons using average adult Japanese male phantom

Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki

JAEA-Data/Code 2014-017, 60 Pages, 2014/10

JAEA-Data-Code-2014-017.pdf:15.4MB
JAEA-Data-Code-2014-017-appendix(CD-ROM).zip:0.62MB

International Commission on Radiological Protection (ICRP) determined reference phantoms based on physique and organ masses (physical characteristics) of Caucasian for dose assessment in the 2007 Recommendations. In internal dosimetry, the reference phantoms are used for calculation of specific absorbed fractions (SAFs). On the other hand, adult Japanese have smaller build than adult Caucasian, and organ masses are different from each other. SAFs depend on physical characteristics. Therefore, differences in physical characteristics between both races can influence dose coefficients. Then, SAFs of average adult Japanese male phantom, JM-103, were calculated by incorporating JM-103 into the general purpose radiation transport code, MCNPX2.6.0, and electron and photon SAFs were evaluated for 25 energies from 10 keV to 10 MeV and for combinations of 67 source regions and 41 target organs. The effect of the difference in build and organ masses between adult Japanese and Caucasian on SAFs was also examined by comparison between the calculated SAFs in this study and SAFs of the reference adult male phantom of ICRP. The SAFs of JM-103 calculated in this study are basic data for assessment of influence of difference in physical characteristics between the races on dose coefficients.

Journal Articles

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

no abstracts in English

Journal Articles

Cabling technology of Nb$$_3$$Sn conductor for ITER central solenoid

Takahashi, Yoshikazu; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; Uno, Yasuhiro; et al.

IEEE Transactions on Applied Superconductivity, 24(3), p.4802404_1 - 4802404_4, 2014/06

 Times Cited Count:16 Percentile:22.38(Engineering, Electrical & Electronic)

Japan Atomic Energy Agency (JAEA) is procuring all amounts of Nb$$_3$$Sn conductors for Central Solenoid (CS) in the ITER project. Before start of mass-productions, the conductor should be tested to confirm superconducting performance in the SULTAN facility, Switzerland. The original design of cabling twist pitches is 45-85-145-250-450 mm, called normal twist pitch (NTP). The test results of the conductors with NTP was that current shearing temperature (Tcs) is decreasing due to electro-magnetic (EM) load cycles. On the other hand, the results of the conductors with short twist pitches (STP) of 25-45-80-150-450 mm show that the Tcs is stabilized during EM load cyclic tests. Because the conductors with STP have smaller void fraction, higher compaction ratio during cabling is required and possibility of damage on strands increases. The technology for the cables with STP was developed in Japanese cabling suppliers. The several key technologies will be described in this paper.

Journal Articles

Improvement for the trip rate of klystron high-voltage power supplies in J-PARC linac

Hori, Toshihiko; Sato, Fumiaki; Shinozaki, Shinichi; Chishiro, Etsuji; Oguri, Hidetomo; Futatsukawa, Kenta*; Fukui, Yuji*

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1001 - 1003, 2014/06

no abstracts in English

Journal Articles

Present status of klystron power supply systems for J-PARC linac 2013

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Miyajima, Noriyuki*; et al.

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.605 - 607, 2014/06

This report describes the present status of the klystron power supply systems for the J-PARC linac. The systems for the 181 MeV linac were operated from September to May. A few breakdowns were occurred, and are described in this report. The new systems for the upgrade of the linac from 181MeV to 400 MeV have been installed until now, and the 3 HVDCPSs and the 3 anode modulators of the new systems have been operated. All the systems for 400 MeV linac will be operated in this autumn.

Journal Articles

Upgrade of power supply system for RF-chopper at J-PARC Linac

Futatsukawa, Kenta*; Ikegami, Masanori*; Ito, Yuichi; Kikuzawa, Nobuhiro; Sato, Fumiaki; Shinozaki, Shinichi; Suzuki, Takahiro*; Chishiro, Etsuji; Hirano, Koichiro; Fang, Z.*; et al.

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1149 - 1153, 2014/06

no abstracts in English

Journal Articles

Upgrade of control signal distribution system at J-PARC Linac

Futatsukawa, Kenta*; Ito, Yuichi; Kikuzawa, Nobuhiro; Kobayashi, Tetsuya*; Sato, Fumiaki; Shinozaki, Shinichi; Suzuki, Takahiro*; Fang, Z.*; Fukui, Yuji*; Michizono, Shinichiro*

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1126 - 1129, 2014/06

no abstracts in English

Journal Articles

Discharge suppression for anode modulator in J-PARC linac

Chishiro, Etsuji; Kawamura, Masato*; Hori, Toshihiko; Sato, Fumiaki; Shinozaki, Shinichi

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1224 - 1226, 2013/08

no abstracts in English

Journal Articles

High power RF test station for RFQII at J-PARC linac

Hori, Toshihiko; Chishiro, Etsuji; Shinozaki, Shinichi; Sato, Fumiaki; Morishita, Takatoshi; Kondo, Yasuhiro; Futatsukawa, Kenta*; Fukui, Yuji*; Kawamura, Masato*; Sugimura, Takashi*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1240 - 1242, 2013/08

no abstracts in English

Journal Articles

Precise measurement of the installed cable attenuation

Futatsukawa, Kenta*; Anami, Shozo*; Kobayashi, Tetsuya*; Fang, Z.*; Fukui, Yuji*; Michizono, Shinichiro*; Sato, Fumiaki; Shinozaki, Shinichi

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.765 - 768, 2013/08

no abstracts in English

Journal Articles

Status of J-PARC linac LLRF after the Tohoku Earthquake

Futatsukawa, Kenta*; Anami, Shozo*; Kobayashi, Tetsuya*; Fang, Z.*; Fukui, Yuji*; Michizono, Shinichiro*; Kawamura, Masato*; Sato, Fumiaki; Shinozaki, Shinichi; Chishiro, Etsuji; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.769 - 773, 2013/08

no abstracts in English

Journal Articles

RF control system for the RFQ test station at J-PARC linac

Fukui, Yuji*; Kawamura, Masato*; Kobayashi, Tetsuya*; Fang, Z.*; Futatsukawa, Kenta*; Sato, Fumiaki; Shinozaki, Shinichi; Suzuki, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.762 - 764, 2013/08

no abstracts in English

Journal Articles

Present status of klystron power supply systems for J-PARC linac 2012; Recovery from Earthquake Disaster, HVDCPS breakdown and energy upgrade

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Yukitake, Mitsuteru*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1243 - 1247, 2013/08

no abstracts in English

143 (Records 1-20 displayed on this page)