基于MCNP程序的铅屏蔽层对γ射线屏蔽性能研究

Study of Shielding Capability of γ-ray for Pb Shielding Floor Based on MCNP Program

为了计算不同厚度铅对不同能量γ射线的屏蔽性能,本工作建立了两种模型,然后使用MCNP程序对这两种模型进行模拟计算,进而得到了铅的屏蔽性能。计算结果表明:相同厚度的铅屏蔽层对低能γ射线的屏蔽能力强于高能,随着γ射线能量的增大,屏蔽能力呈下降趋势。作为验证,本工作计算了单向源、面源、各向同性面源情况下铅的屏蔽性能,还通过改变PHYS卡计算铅的屏蔽性能,得到的结果与上述结论一致。

For calculating the shielding capability of γ-ray with different energy for Pb shielding floor with different thickness, two models were conceived, then these models were simulated with MCNP program, and the Pb shielding capability was calculated and the conclusion was gained. The results show that the shielding capability of Pb shielding floor with the same thickness to low energy γ-ray is better than to high energy γ-ray, and the shielding capability line descends along with the γ-ray energy goes up. For validating this conclusion, the Pb shielding capability in the conditions of single direction γ-ray source, surface source, isotropy surface source and changing PHYS card were calculated, then the same conclusions were gained.