@misc{oai:repo.qst.go.jp:00086586, author = {Masayuki, Naito and Yuki, Tamakuma and Kazuaki, Yajima and Eunjoo, Kim and Satoshi, Obara and Osamu, Kurihara and Masayuki, Naito and Yuki, Tamakuma and Kazuaki, Yajima and Eunjoo, Kim and Satoshi, Obara and Osamu, Kurihara}, month = {Apr}, note = {In case of nuclear accidents, it is important to determine the magnitude of radiation doses received by people living in contaminated territories. Direct measurement of individual external doses using personal dosimeters (PDs) worn by subjects is the most reliable solution for this necessity. However, it is not practical to expect that all returnees to the affected areas wear PDs. Thus, conversion factors from the ambient dose equivalent (ADEs) to the effective dose for various aged individuals must be determined appropriately. Previous studies demonstrated that the ratio of PDs to ADEs at various areas of Fukushima Prefecture mostly existed in the range of 0.6-0.7 [e.g.,1-3]. These studies provided evidence that PD readings would be reasonable estimators for the effective doses of adult subjects at locations where radioactive cesium is widely and uniformly deposited on the ground. In the present study, we experimentally obtained the response of PDs (D-shuttle, Chiyoda Technol., Tokyo, Japan; Dose i, Fuji Electric, Tokyo, Japan) attached to the front of five age-specific anthropometric phantoms (newborn, 1 y, 5y, 10y and adult male) for lateral radiations of 137Cs with various rotational angles. The PD/ADE ratio for the D-shuttle on the five phantoms with rotational irradiation simulating the exposure in Fukushima Prefecture were 0.87, 0.85, 0.83, 0.83 and 0.77, respectively. The ratio for newborns was 11 % higher than that for adult males. This body size dependency can be explained by the PD response to exposure direction. We discussed the results of this study and our field experiments to construct conversion coefficients from the ADE to the effective doses for age-group residents living in affected areas, which will be presented at the conference., International Conference on Individual Monitoring of Ionising Radiation (IM2022) and Neutron and Ion Dosimetry Symposium (NEUDOS-14)}, title = {Conversion coefficients from ambient dose equivalent to effective doses of various age groups in areas affected by the 2011 Fukushima nuclear disaster}, year = {2022} }