不同计算模型对水中γ射线吸收剂量累积因子的影响

Effect of different models on gamma-ray buildup factor for energy absorption in water

为了开展不同计算模型对累积因子的影响研究,本文基于蒙特卡罗程序Geant4,分别使用无限大介质模型及无限大平板模型对水中的吸收剂量累积因子进行了计算,比较分析了不同计算模型下累积因子数据之间的差异,最终建立了水中无限大平板模型下累积因子与无限大介质模型下的累积因子之间的定量关系。该关系不受光子能量和自由程数的影响,可通过较少的参数和无限大介质下的累积因子值计算出无限大平板下的累积因子,能有效地减少累积因子在实际使用时由于模型不同而引起的误差,提高了累积因子的实用性。本文工作可为其他介质材料的相关研究提供参考。

Using the Monte Carlo simulation code Geant4, Energy absorption buildup factors in water under the infinite medium model and the infinite slab model were both calculated. The results of the two different kinds of buildup factors were compared and analyzed, and the quantitative relationship between them was established. The relationship is not influenced by the photon energy and mean free path ( MFP), and the buildup factors under the infinite plate model can be calculated by using the corresponding values under the infinite medium model through a few parameters, which can effectively reduce the errors caused by the different models in the actual calculation and improve the practicability of the buildup factors. The work in this paper can provide reference for the related research in other materials.