GEANT4 calculations of neutron dose in radiation protection using a homogeneous phantom and a Chinese hybrid male phantom
Abstract
The purpose of this study is to verify the feasibility（可行性） of applying GEANT4 (version 10.01) in neutron dose calculations in radiation protection by comparing the calculation results with MCNP5. The depth dose distributions are investigated in a homogeneous phantom, and the fluence-to-dose conversion coefficients are calculated for different organs in the Chinese hybrid male phantom for neutrons with energy ranging from 1 × 10−9 to 10 MeV. By comparing the simulation results between GEANT4 and MCNP5, it is shown that using the high-precision (HP) neutron physics list, GEANT4 produces the closest simulation results to MCNP5. However, differences could be observed when the neutron energy is lower than 1 × 10−6 MeV. Activating the thermal scattering with an S matrix correction in GEANT4 with HP and MCNP5 in thermal energy range can reduce the difference between these two codes.
首先很多概念可能不很好翻译，暂时只是自己的一点看法
G4在很多模拟真正部署的时候都要进行相关的验证分析，因为G4本来并不一定在某个具体领域经过反复详细的验证。本文是作者使用G4和MCNP对同样的中子照射人体模型的分析情况，主要计算中子剂量，体模用了两种，一种是均匀体模，一种是中国男性人体混合体模，计算了均匀体模的深度剂量分布，还计算了中国男性混合体摸的不同器官的注量-剂量转换系数。模拟的中子能量范围是0.001eV到10MeV，结果表明，使用G4的HP（高精度）中子物理模型，可以得到与MCNP最接近的结果。但是低于1eV的时候出现了较大差别，文章采用了S矩阵矫正从而激活热中子散射的方法解决了在热中子能区两者差别巨大的问题。但是这里存在问题，如何进行的S矩阵矫正？这样做的依据是经验的？凑数的还是别的，是需要将来思考的一个问题。
最近帮人看一个模拟，也是在较低能中子模拟的时候与理论数值计算存在较大偏离，没有使用MCNP计算过，因此尚需考虑。