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Journal Articles

Series studies on inter-comparison of radiation calibration fields and calibration techniques between KAERI and JAEA

Yoshitomi, Hiroshi; Tanimura, Yoshihiko*; Tatebe, Yosuke; Tsutsumi, Masahiro; Kawasaki, Katsuya; Kowatari, Munehiko; Yoshizawa, Michio; Shimizu, Shigeru*; Kim, J.-S.*; Lee, J.-G.*; et al.

Proceedings of 4th Asian and Oceanic Congress on Radiation Protection (AOCRP-4) (CD-ROM), 4 Pages, 2015/07

JAEA Reports

Establishment of X-ray reference fields for performance tests of radiation measuring instruments based on international standard

Shimizu, Shigeru; Sawahata, Tadahiro*; Kajimoto, Yoichi; Shikaze, Yoshiaki; Yoshihara, Yasuaki*; Tatebe, Yosuke

JAEA-Technology 2011-008, 53 Pages, 2011/06

JAEA-Technology-2011-008.pdf:2.91MB

The International Standard, ISO 4037-1, is applied worldwide for setting the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. X-ray reference fields were established at the Facility of Radiation Standard in Nuclear Science Research Institute in 2003 and had been operated. Recently, we rebuilt the X-ray reference fields by replacing the X-ray tube with a new model due to the damage of the old one of the middle-hard X-ray irradiation device. We have established three series of medium-hard X-ray reference fields, Narrow, Wide and High air-kerma series with 27 radiation qualities, based on ISO 4037-1. This article described quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalent from Air-kerma and comparison with the quality of ISO 4037-1 in the X-ray fields of medium-hard X-ray voltages ranging from 20 kV to 300 kV. Result of experiments, these X-ray reference fields were well agreed with the condition of the international standard. As a result, these X-ray reference fields were found to be used to carry out the performance test, standard irradiation based on the international standard, and an intercomparison experiment with the reference laboratories in the world.

JAEA Reports

Establishment of medium-hard X-ray reference fields for performance tests of radiation measuring instruments based on national standard

Shimizu, Shigeru; Sawahata, Tadahiro; Kajimoto, Yoichi; Shikaze, Yoshiaki; Yoshihara, Yasuaki*; Tatebe, Yosuke

JAEA-Technology 2010-009, 78 Pages, 2010/06

JAEA-Technology-2010-009.pdf:3.06MB

In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. We renewed a X-ray tube of the medium-hard X-ray irradiation device that was damaged in the Facility of Radiation Standards in Nuclear Science Research Institute. Therefore, we established four series of medium-hard X-ray reference fields with quality index of 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this process, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalents from Air-kerma were evaluated in the medium-hard X-ray fields produced with X-ray tube voltage ranging from 20kV to 300kV. As a result, medium-hard X-ray reference fields were established that can provide the dose equivalent standard with good precision and wide range of test energy points and dose rates. We clarified these detailed data.

JAEA Reports

Establishment of soft X-ray reference fields for performance tests of radiation measuring instruments based on national standard

Shimizu, Shigeru; Fujii, Katsutoshi; Kawasaki, Tomokatsu

JAEA-Technology 2010-005, 72 Pages, 2010/06

JAEA-Technology-2010-005.pdf:2.44MB

In the Japanese Industrial Standard, JIS Z 4511 sets the condition of X-ray reference fields to be used for the performance test of radiation measuring instruments for radiation protection. With the soft X-ray generator installed in the Facility of Radiation Standard in Nuclear Science Research Institute, we have established four series of soft X-ray reference fields with quality index 0.6, 0.7, 0.8 and 0.9 based on JIS Z 4511. In this process, quality of the X-ray fields, X-ray spectra, conversion coefficients to the dose equivalent from Air-Kerma were evaluated in the soft X-ray fields produced with X-ray tube voltage ranging from 6 kV to 100 kV. As a result, it is found that dose equivalent standard with good precision and wide range of test energy point and dose rates can be provided, this report describes these detailed data.

Journal Articles

Outline of the draft JIS on the calibration method of beta radiation dose equivalent meters

Shimizu, Shigeru

Hokeikyo Nyusu, (45), p.4 - 5, 2010/04

In domestic JIS original bill making Committee, JIS original bill about the calibration method of the beta radiation dose equivalent meters were discussed newly, and it was reported to Japan Standards Association. Therefore I comment on the summary of this original bill and the future prospects including knowledge as the making committee.

Journal Articles

Contribution of the facility of radiation standards to the reliability enhancement in radiation measurement in Japan

Shimizu, Shigeru

Dai-1-Kai (Heisei-20-Nendo) Genshiryoku Rekishi Kochikusho, p.107 - 108, 2009/11

no abstracts in English

Journal Articles

Development of the neutron calibration fields using accelerators at FRS and TIARA of JAEA

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:49.21(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.

Journal Articles

Volume recombination of C$$^{4+}$$ in detached divertor plasmas of JT-60U

Nakano, Tomohide; Kubo, Hirotaka; Asakura, Nobuyuki; Shimizu, Katsuhiro; Konoshima, Shigeru; Fujimoto, Kayoko; Kawashima, Hisato; Higashijima, Satoru

Nuclear Fusion, 47(11), p.1458 - 1467, 2007/11

 Times Cited Count:20 Percentile:57.75(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Construction of monoenergetic neutron calibration fields using $$^{45}$$Sc(p,n)$$^{45}$$Ti reaction at JAEA

Tanimura, Yoshihiko; Saegusa, Jun; Shikaze, Yoshiaki; Tsutsumi, Masahiro; Shimizu, Shigeru; Yoshizawa, Michio

Radiation Protection Dosimetry, 126(1-4), p.8 - 12, 2007/08

 Times Cited Count:12 Percentile:63.81(Environmental Sciences)

no abstracts in English

Journal Articles

Evaluation of the characteristics of the neutron reference field using D$$_{2}$$O-moderated $$^{252}$$Cf source

Kowatari, 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:37.26(Environmental Sciences)

The facility of the Radiation Standards (FRS) of the Japan Atomic Energy Agency was equipped with the reference neutron field by using D$$_{2}$$O moderated $$^{252}$$Cf neutron source (D$$_{2}$$O-Cf), with a 30cm diameter D$$_{2}$$O 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 D$$_{2}$$O 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$$^{*}$$$$phi$$(10) and h$$_{p}$$$$phi$$(10)) and neutron dose rates (H$$^{*}$$(10) and H$$_{p}$$(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.

Journal Articles

Commencement of outside usage of radiation standard facility of JAEA

Shimizu, Shigeru

Hokeikyo Nyusu, (39), p.2 - 3, 2007/05

We have started the outside usage system of various irradiation equipment of Facility of Radiation Standards of JAEA in November, 2006. This article describes the outline of the facility, usage system, administrative procedure for use. In addition, it mentions the role of Institute of Radiation Measurement in relation to the outside usage of the facilities.

Journal Articles

Radiation processes of impurities and hydrogen in detached divertor plasmas of JT-60U

Nakano, Tomohide; Kubo, Hirotaka; Asakura, Nobuyuki; Shimizu, Katsuhiro; Konoshima, Shigeru; Fujimoto, Kayoko; Kawashima, Hisato; Higashijima, Satoru

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03

Volume recombination of C$$^{4+}$$ and $$e^{-}$$ into C$$^{3+}$$ is observed for the first time in detached plasmas with MARFE. It is found that the recombination flux of C$$^{4+}$$ to C$$^{3+}$$ is comparable to the ionization flux of C$$^{3+}$$ to C$$^{4+}$$, and that the recombination zone is above an X-point and beneath the ionization zone. This result suggests that this volume recombination predominantly produces C$$^{3+}$$ ions, which contribute 60-80 % to the total radiation power in the divertor plasma.

Journal Articles

Calibration standards in radiation protection dosimetry at the NSRI of JAEA

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-, $$gamma$$-, $$beta$$-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.

JAEA Reports

Operation and maintenance manual of the accelerator installed in the facility of radiation standards

Fujii, Katsutoshi; Kawasaki, Katsuya; Kowatari, Munehiko; Tanimura, Yoshihiko; Kajimoto, Yoichi; Shimizu, Shigeru

JAEA-Testing 2006-005, 146 Pages, 2006/08

JAEA-Testing-2006-005.pdf:19.71MB

4MV Van de Graff accelerator was installed in the Facility of Radiation Standards (FRS) in June 2000, and monoenergetic neutron calibration fields and high energy $$gamma$$-ray calibration fields have been developed. The calibration fields are provided for R&D on dosimetry, and for the calibration and type-test of radiation protection instruments. This article describes the operational procedure, the maintenance work and the operation of the related apparatuses of the accelerator. This article focuses on the sufficient safety and radiation control for the operators, the maintenance performance of the accelerator, and on the prevention of the malfunction due to the mistakes of the operator. This article targets the unexperienced engineers in charge of operation and maintenance of the accelerator.

Journal Articles

Impact of wall saturation on particle control in long and high-power-heated discharges in JT-60U

Nakano, Tomohide; Asakura, Nobuyuki; Takenaga, Hidenobu; Kubo, Hirotaka; Miura, Yukitoshi; Shimizu, Katsuhiro; Konoshima, Shigeru; Masaki, Kei; Higashijima, Satoru; JT-60 Team

Nuclear Fusion, 46(5), p.626 - 634, 2006/05

 Times Cited Count:20 Percentile:57.39(Physics, Fluids & Plasmas)

In order to understand plasma-wall interactions in a long time scale, the discharge pulse length has been extended from 15 s to 65 s, with the NB-heating duration extended to 30 s. Nearly-saturation of the divertor plates was observed in the latter half of long pulse ELMy H-mode discharges. Particle sink into the divertor plates gradually decreased, and subsequently, wall-pumping efficiency became zero. This wall saturation resulted in a rise of the main plasma density without any auxiliary particle supply besides NB with divertor-pumping. Even when the total injected energy reached up to $$sim$$ 350 MJ in a discharge, neither sudden increase of carbon generation such as carbon bloom nor increase of the dilution of the main plasma was observed.

Journal Articles

Study of global wall saturation mechanisms in long-pulse ELMy H-mode discharges on JT-60U

Takenaga, Hidenobu; Nakano, Tomohide; Asakura, Nobuyuki; Kubo, Hirotaka; Konoshima, Shigeru; Shimizu, Katsuhiro; Tsuzuki, Kazuhiro; Masaki, Kei; Tanabe, Tetsuo*; Ide, Shunsuke; et al.

Nuclear Fusion, 46(3), p.S39 - S48, 2006/03

 Times Cited Count:18 Percentile:52.52(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Single-ended pelletron accelerator at JAERI-TOKAI

Takahashi, Masa; Fujii, Katsutoshi; Tanimura, Yoshihiko; Shimizu, Shigeru; Kajimoto, Yoichi; Kowatari, Munehiko; Yoshizawa, Michio; Yamamoto, Hideaki

Dai-18-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.110 - 113, 2005/11

no abstracts in English

JAEA Reports

Characteristics of thermal neutron calibration fields using a graphite pile

Uchida, Yoshiaki*; Saegusa, Jun; Kajimoto, Yoichi; Tanimura, Yoshihiko; Shimizu, Shigeru; Yoshizawa, Michio

JAERI-Tech 2005-012, 31 Pages, 2005/03

JAERI-Tech-2005-012.pdf:4.58MB

no abstracts in English

Journal Articles

Effects of long time scale variation of plasma wall interactions on particle control in JT-60U

Takenaga, Hidenobu; Nakano, Tomohide; Asakura, Nobuyuki; Kubo, Hirotaka; Konoshima, Shigeru; Shimizu, Katsuhiro; Tsuzuki, Kazuhiro; Ide, Shunsuke; Fujita, Takaaki

Proceedings of 4th IAEA Technical Meeting on Steady-State Operation of Magnetic Fusion Devices and MHD of Advanced Scenarios (Internet), 8 Pages, 2005/02

no abstracts in English

Journal Articles

Construction of 144, 565 keV and 5.0 MeV monoenergetic neutron calibration fields at JAERI

Tanimura, Yoshihiko; Yoshizawa, Michio; Saegusa, Jun; Fujii, Katsutoshi; Shimizu, Shigeru; Yoshida, Makoto; Shibata, Yasunari*; Uritani, Akira*; Kudo, Katsuhisa*

Radiation Protection Dosimetry, 110(1-4), p.85 - 89, 2004/09

 Times Cited Count:19 Percentile:75.31(Environmental Sciences)

Mono-energetic neutron calibration fields have been developed at the Facility of Radiation Standards (FRS) of JAERI using 4MV Van-de-Graaff (Pelletron) accelerator. The fields of 144 keV, 565 keV and 5.0 MeV neutrons were constructed with estimating neutron energy spectra and establishing the traceability of reference neutron fluence.

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