用窄束γ能谱特征峰法测非均匀材料吸收系数的研究

Study on the measurement of absorption coefficient of inhomogeneous materials by narrow beam γ spectral characteristic peak method

在γ射线的有效屏蔽中,选择合适的窄束孔径以及有效测量屏蔽材料的屏蔽系数至关重要.利用MCNP方法选择合适的孔径;采用γ能谱特征峰法可以得到测量材料的线吸收系数,而对于非均匀性材料的线性吸收系数采用多点测量法.得到新型重晶石混凝土(非均匀性)的线性吸收系数为0.2065 cm^(-1),此结果对于实际中不均匀材料提供一种测量吸收系数的方法.

In the effective shielding of γ rays, it is very important to choose a suitable narrow beam aperture and effectively measure the shielding coefficient of the shielding material.The MCNP method was used to select the appropriate aperture, the γ energy spectrum characteristic peak method can be used to obtain the linear absorption coefficient of the measured material.While the linear absorption coefficient of the non-uniform material was measured by the multi-point method.The linear absorption coefficient of spar concrete(non-uniformity) was 0.206 5 cm^(-1),which provides a method for measuring the absorption coefficient of non-uniform materials in practice.