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Yoshitomi, Hiroshi; Kowatari, Munehiko
Radiation Protection Dosimetry, 170(1-4), p.199 - 203, 2016/09
Times Cited Count：4 Percentile：36.53(Environmental Sciences)Both cylinder and slab phantoms have been recommended for the calibration phantoms for eye lens dosimetry in the |IAEA TECDOC. This study aims to investigate the influence of these phantoms on the calibration of dosemeters for eye lens dosimetry. In order to fulfill the purpose, the backscatters of photons and electrons from practically used water-filled phantoms were evaluated by calculations and experiments. Calculations showed cylinder phantom and slab phantom were found to well-simulate the effect of backscattered photons within 10% and 5%, respectively. It was also found that a cylinder phantom had 10% lower backscattered effect over the range of 50-100 keV. Due to this, the measured calibration factors of cylinder phantom for non-filtered Optically Stimulated Luminescence (OSL) and Radio-Photo Luminescence (RPL) dosemeters increased by 20% and 10%, respectively when compared to the slab phantom. For electrons, no difference was found between cylinder and slab phantoms.
Hertel, N. E.*; Bartlett, D. T.*; Dietze, G.*; Bordy, J.-M.*; Endo, Akira; Gualdrini, G.*; Pelliccioni, M.*; Ambrosi, P.*; Siebert, B. R. L.*; Veinot, K.*; et al.
no journal, ,
The International Commission on Radiation Units and Measurements (ICRU) defines a set of operational quantities for use in radiation measurements that provides assessment of the protection quantities recommended by International Commission for Radiological Protection (ICRP). The ICRU operational quantities in current use was defined about 30 years ago. ICRU Report Committee 26 has examined the rationale for operational quantities taking into account the changes in the definitions of the protection quantities and the changes in the fields of application of the operational quantities and protection quantities. The considerations have included the range of types and energies of particles contributing to doses to workers and members of the public. The relationship of the existing recommended operational quantities to the protection quantities has been investigated, as has the impact of changes in routine measurement practice, including instrument design and calibration. The committee has proposed a set of operational quantities which differs from the previous quantities. The major change in the proposed set of quantities is the redefinition of the operational quantities for area monitoring from doses computed at a depth in the ICRU sphere to ones based on particle fluence and the relationship to the protection quantities, effective dose, and equivalent dose to the lens of the eye, and local skin.
ray (R-F) reference fieldKowatari, Munehiko; Yoshitomi, Hiroshi; Yoshizawa, Michio
no journal, ,
Calibration factors for widely available active and passive dosemeters (Aloka PDM-122-SZ and PDM-222-SZ, Fuji NRF31, Glass-Dosemeters (GD) and OSL) in Japan were obtained under conditions with and without BUPs in the 6-7 MeV high energy ray reference field. As for the condition with the BUP, calibration factors for personal dosemeters were obtained in accordance with the recommendation of ISO 4037-3, using a PMMA-made BUP with the dimension of 30 
30 2.5 cm
. Irradiating the same personal dosemeters without the BUP, calibration factors were then obtained and comparison was made with those under the condition of BUP. Calibration factors of each dosemeter obtained under the condition with the thick BUP were determined to be between 0.91 and 1.0. On the other hand, calibration factors of GD and OSL were determined to be less than 0.7. This implies that readings of GD and OSL would overestimate under the condition which charged particle equilibrium was not properly achieved.
