10 0 0 0 OA 自然放射線における空気吸収線量から実効線量当量への換算係数の評価
- 著者
- 森内 茂 堤 正博 斎藤 公明
- 出版者
- Japan Health Physics Society
- 雑誌
- 保健物理 (ISSN:03676110)
- 巻号頁・発行日
- vol.25, no.2, pp.121-128, 1990 (Released:2010-02-25)
- 参考文献数
- 13
- 被引用文献数
- 21 26
A practical conversion factor to estimate the value of effective dose equivalent rate in Sv unit from absorbed dose rate in air in Gy unit was examined for natural gamma radiations. The experimental examination was carried out by two methods; one measures the effective dose equivalent rate directly by using a measuring instrument having effective dose equivalent response for isotropic gamma radiations and the other obtaines it from calculation applying the gamma flux-to-effective dose equivalent factor to actual gamma energy spectrum measured in various indoor and outdoor places.From these investigations the value of the quotient of effective dose equivalent to absorbed dose in air was found do be 0.748±0.007 Sv per Gy for natural radiation exposures in various environments. The value of the quotient 0.7, which is adopted to applied to environmental gamma radiations in the UNSCEAR 1982 and 1988 Reports, was clarified to be about 7% lower than the one obtained experimentally for natural gamma radiations.
6 0 0 0 OA I. 原子力事故後の環境中外部被ばく線量の測定・評価に関する研究
- 著者
- 森内 茂 堤 正博 斎藤 公明
- 出版者
- 日本保健物理学会
- 雑誌
- 保健物理 : hoken buturi (ISSN:03676110)
- 巻号頁・発行日
- vol.42, no.1, pp.71-83, 2007-03
- 被引用文献数
- 4
Gamma ray spectra analyses using unfolding techniques and the dose evaluation are performed widely in the fields of environmental radiation monitoring and the relating environmental research. Various sizes and the shapes of NaI (Tl) scintillation detectors can be used depending on the dose levels. However, available response functions are generally limited to 3"φ×3" cylindrical and 3"φ spherical types and the energy range is roughly up to 3 MeV. In this paper, the response functions of eight types of cylindrical and spherical NaI (Tl) scintillation detectors (1"φ×1", 2"φ×2", 3"φ×3", 4"φ×4", 5"φ×4" cylindrical, and 2"φ, 3"φ, 5"φ spherical) were determined. The energy ranges were extended to 10 MeV in maximum. The some response functions reported in literatures were unfolded using our response matrices for comparison and the relative characteristics were discussed.
1 0 0 0 OA 積雪による地殻γ線線量率の減衰
- 著者
- 長岡 鋭 坂本 隆一 斎藤 公明 堤 正博 森内 茂
- 出版者
- 日本保健物理学会
- 雑誌
- 保健物理 (ISSN:03676110)
- 巻号頁・発行日
- vol.23, no.4, pp.309-315, 1988 (Released:2010-02-25)
- 参考文献数
- 15
- 被引用文献数
- 3 6
In order to clarify the diminution characteristics of terrestrial gamma ray exposure rate due to snow cover, measurements were performed on the ground with and without snow cover. The diminution factors observed were 0.36-0.17 for 12-23g/cm2 of water equivalent of the snow cover. According to a calculation by the Monte Carlo method, the corresponding diminution factors were 0.32-0.16. They agreed well as a whole, while the fluctuation of the diminution factors based on the measured exposure rate were fairly large. The fluctuation is deemed to be due to the inhomogeneity in the distribution of the snow cover as well as the gamma ray field. The fluctuation is expected to decrease with increase in the degree of their homogeneity.