Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kowatari, Munehiko*; Yoshitomi, Hiroshi; Tani, Kotaro*; Tanimura, Yoshihiko; Kurihara, Osamu*
Radiation Protection Dosimetry, 200(16-18), p.1574 - 1579, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)Seito, Hajime*; Yokozuka, Eri*; Oka, Toshitaka; Kitatsuji, Yoshihiro; Nagasawa, Naotsugu*
Radiation Protection Dosimetry, 200(16-18), p.1656 - 1659, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)We have examined dosimetric characteristics of bio-inspired carbonated hydroxyapatite (CO
HAp), which is a main component of calcified tissues like tooth enamel. COHAp powder samples were exposed to gamma-ray with radiation doses ranging from 1 Gy to 1000 Gy at room temperature, and ESR spectra were measured immediately after irradiation and subsequently measured each 1 day during 90 days. The post-irradiation fading resulted in significant 20% decay of the signal amplitude, which stabilised within 7 days after irradiation, and the intensity approached a constant. The sample has good linear dose response in the experiment range of 10 Gy - 1000 Gy. Our results indicate that the COHAp materials is suitable for chemical dosimetry.
Kitamura, Yoshimasa; Oka, Toshitaka; Seito, Hajime*; Yokozuka, Eri*; Nagasawa, Naotsugu*; Kitatsuji, Yoshihiro
Radiation Protection Dosimetry, 200(16-18), p.1660 - 1665, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)In this work, we evaluated the applicability of hydroxyapatite, which is a main component of tooth enamel, as individual dosimeters that can detect from less than 1 Gy to several tens Gy. Commercially available hydroxyapatite was irradiated by 
Co gamma-ray up to 75 Gy and ESR spectrum of the irradiated sample was observed. The relationship between the intensity of produced carbonated radical and the absorbed dose shows a good linearity (
) from 0 to 75 Gy. The detection limit of this samples was estimated to be 99.7 mGy, and the radical intensity do not change for eight month from the irradiation. These results suggest that this sample can be used as a candidate of the individual dosimeter.
-ray visualization survey meter in high gamma and neutron background environmentTsubota, Yoichi; Kobayashi, Kenji; Ishii, Tatsuya; Hirato, Misaki; Shioya, Satoshi; Nakagawa, Takahiro
Radiation Protection Dosimetry, 200(16-18), p.1676 - 1680, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)In the decommissioning of the Fukushima Daiichi Nuclear Power Station (FDNPS, 1F), workers are removing structures from inside the buildings, monitoring radioactive contamination, and decontaminating inside the buildings. For the measurement of contamination of suit surfaces of workers, we have developed a hand-held survey meter that can measure and visualize surface radioactive contamination of -nuclides in a high 
/ 
-ray background environment. In order to selectively measure -nuclides, we designed and built a prototype hand-held survey meter for -rays, which consists of a thin-film ZnS:Ag scintillator, a multi-anode photomultiplier tube (MA-PMT), individual amplification and counting circuits for each channel of the MA-PMT. Based on the result of -ray counting, the developed device is capable of counting the -radiation beyond 2.1
10
cpm. In the -ray response test, there was no -ray response even when the detector was in close proximity to a high intensity source; The dose rate was estimated to be more than 1 Sv/h. In the future, we plan to reduce the weight and size of the device, as well as improve the usability of the device through actual testing in contaminated environments.
Kujiraoka, Ikuo; Noguchi, Yoshihiro*; Shimada, Kazumasa; Hirouchi, Jun; Takahara, Shogo
Radiation Protection Dosimetry, 200(16-18), p.1561 - 1567, 2024/11
Times Cited Count：0 Percentile：0.00(Environmental Sciences)Lifetime Attributable Risk (LAR) of cancer induced by radiation exposures is one of the important factors for deciding about radiological protection measures or protective actions for nuclear emergency preparedness and response. In Japan, while a model for estimating LAR for the Japanese population has been developed based on epidemiological data from A-bomb survivors, a flexible projection code implementing this model needs to be developed. This study investigated the existing codes to contribute to the development of the projection code. Based on these investigations, we compared their LAR calculation results, and explored the cause of their differences.
Oka, Toshitaka; Takahashi, Atsushi*; Miura, Tomisato*; Shinoda, Hisashi*
no journal, ,
From the point of view of dosimeter, tooth enamel has a great sensitivity to radiation and it can be a powerful probe to detect dose from the order of mGy to Gy. In this work, we evaluated the performance of tooth enamel as a high sensitive solid-state dosimeter. Absorbed dose estimated by ESR dosimetry technique was consistent with dose measured by a commerical pocket dosimeter within an error bar, It suggests that tooth enamel can be use as a "non-directional characteristics" dosimeter, which detect dose in mGy order as well as a commercial pocket dosimeter.
Ba to simulate 
I dispersed in the environmentTsuji, Tomoya; Yoshitomi, Hiroshi; Kowatari, Munehiko*; Tanimura, Yoshihiko
no journal, ,
