γ-Ray Buildup Factors:2013（AESJ-SC-A005E：2013）

内容紹介

＜FOREWORDより＞

“γ-ray Buildup Factors: 2013” provides γ-ray buildup factors for use in γ-ray shielding
calculations. This standard has been approved by the Atomic Energy Society of Japan
upon deliberation by the Subcommittee on Radiation Shielding, the Advanced and
Fundamental Systems Technical Committee.
The γ-ray buildup factor is defined by the ratio of total γ-ray dose included scattered
γ-ray contribution to dose of unscattered γ-ray which has no experience of collision from
source point to evaluation point in the passage of radiation through a medium. γ-ray
buildup factors are used in the point kernel method of γ-ray shielding calculations.
With 20 years having passed since the publication of γ-ray attenuation coefficients and
the buildup factors by the standard committee of American Nuclear Society at 1991, the
extension of data is needed for the evaluation of effective dose and ambient dose
equivalent in the γ-ray shielding calculations. The codes also advanced for the
evaluation of γ-ray buildup factors.
In this report, γ-ray buildup factors obtained by IE (Invariant Embedding) method and
those GP (Geometric Progression) formula parameters appeared for 28 materials with
the energy range from 0.015 MeV to 15 MeV, in the 3 cases of high-atomic number
materials from 0.03 MeV to 15 MeV, up to 100 mfp (mean free path), 5 dose quantities of
exposure, effective dose with AP and ISO irradiation geometries, absorbed dose and
ambient dose equivalents. GP formula is able to interpolate the buildup factors in the
desired thickness of materials. γ-ray attenuation coefficients of each material are also
appeared for the help of γ-ray point kernel method. The energy response functions for
each quantity of interest are also listed.