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Hoshi, Katsuya; Nishino, Sho; Yoshida, Tadayoshi; Tsujimura, Norio
JPS Conference Proceedings (Internet), 24, p.011020_1 - 011020_6, 2019/01
We studied the application of AmLi interrogation neutron sources, which originally deployed in non-destructive assay apparatus for nuclear safeguard, to calibration work. To determine the emission rate, the angular distribution of neutron fluence was measured by a potable long counter. The emission rate at the date of measurement (October 23rd, 2015) was determined to be 1.0010 n/s (4.1% ( = 2)).
Saegusa, Jun; Tanimura, Yoshihiko; Yoshizawa, Michio; Yoshida, Makoto
Radiation Protection Dosimetry, 110(1-4), p.91 - 95, 2004/09
Times Cited Count:4 Percentile:23.52(Environmental Sciences)For the accurate estimation of neutron dose equivalents, it is important to calibrate dosemeters in the field whose energy spectrum is similar to that in the workplace. For the purpose, studies are made toward the built of the spectrum changeable neutron calibration fields with the Van-de-Graff accelerator in the FRS in JAERI. The fields are produced by bombarding proton or deuteron beam from the accelerator to suitable targets surrounded by quasi-cylindrical moderators and absorbers of various materials. In the fields, neutron spectra with wide range energy index should be provided with sufficient fluence rate for the calibration of dosemeters. The objectives and conceptual design of the fields are discussed here, followed by the test simulation results of neutron spectra produced by various arrangements of a target and moderators.
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:75.21(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.
Yoshizawa, Michio; Tanimura, Yoshihiko; Saegusa, Jun; Nemoto, Hisashi*; Yoshida, Makoto
Radiation Protection Dosimetry, 110(1-4), p.81 - 84, 2004/09
Times Cited Count:3 Percentile:23.52(Environmental Sciences)The facility of Radiation Standards (FRS) of JAERI has equipped with the concrete-moderated neutron calibration fields as simulated workplace neutron fields. The fields use an Am-Be (37GBq) neutron source placed in the narrow space surrounded by concrete wall and bricks to produce scattered neutrons. The neutron spectra of the fields were measured with Bonner multi-sphere spectrometer system (BMS), spherical recoil-proton proportional counters (RPCs), and a liquid scintillation counter (NE-213). The results were compared with each other, and the neutron spectra and the ambient dose equivalent rate, (10), were agreed well within the uncertainty. The angular distributions of neutron fluence were calculated by the MCNP-4B2 Monte Carlo code to obtain the reference personal dose equivalent rate, (10). The calculated results show that the scattered neutrons have a wide variety of incident angles. The reference (10) values considered the angular distribution were found to be 10-18% smaller than those without consideration.
Yoshizawa, Michio; Endo, Akira
JAERI-Conf 2003-002, 166 Pages, 2003/03
The present report is Proceedings of the Third Workshop on Dosimetry for External Radiations, held at the Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), in November 28-29, 2002. The proceedings comprises 16 papers and a summary of general discussion. The Third Workshop, subtitled "On an opportunity of the completion of the facility of calibration standards for neutron at JAERI", focused on neutron dosimetry and included presentations on the status of international neutron standards, the development of calibration techniques of neutron dosimeters using accelerator neutron sources, and dosimetry for high-energy neutrons. The workshop identified the directions for the future research and development in this field.
Hoshi, Katsuya; Nishino, Sho
no journal, ,
no abstracts in English
Nishino, Sho; Umino, Kazushige*; Yoshitomi, Hiroshi; Fukami, Tomoyo; Tsuji, Tomoya; Tanimura, Yoshihiko
no journal, ,
In the Facility of Radiation Standards (FRS) of JAEA, mono-energetic neutron calibration fields and a high-energy -ray calibration field using a 4MV Van de Graaff accelerator has been established, for calibration or characteristic tests of radiation measuring instruments. In this presentation, usage status and details of troubles occurred in the FRS accelerator in recent years will be reported.