ABSTRACT An effective dose calculation method is important in the design of efficient shields in radiation facilities. Some analytical methods have been shown to provide a simple and quick design analysis; however, no suitable method exists that can be applied to a room located directly under an X-ray irradiation room. We propose a new analytical method that uses the multiple reflection ratio predetermined by a Monte Carlo simulation and the differential dose albedo given by the Chilton–Huddleston semi-empirical equation. Our method is verified by comparison with the Monte Carlo simulation, performed for the case of an electron linac facility with an accelerated energy of 10 MeV, where the shielding floor has a thickness of 1.6–2.0 m and the downstairs room has a height of 0.5–1.5 m. The difference between the effective X-ray doses in the downstairs room calculated via the proposed analytical method and the Monte Carlo simulation is less than 25% when the horizontal distance from the X-ray beam to the evaluation point exceeds 3 m and the evaluation point is set at half of the height of the room. The new analytical method can be efficiently and accurately applied to the calculation of the effective dose.

中文翻译：

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直线加速器楼下房间有效剂量计算方法的开发

摘要 有效剂量计算方法在辐射设施的高效屏蔽设计中很重要。一些分析方法已被证明可以提供简单快速的设计分析；然而，没有合适的方法可以应用于位于 X 射线照射室正下方的房间。我们提出了一种新的分析方法，该方法使用由蒙特卡罗模拟预先确定的多次反射比和由 Chilton-Huddleston 半经验方程给出的微分剂量反照率。我们的方法通过与 Monte Carlo 模拟的比较得到验证，该模拟是针对加速能量为 10 MeV 的电子直线加速器设施进行的，其中屏蔽地板的厚度为 1.6-2.0 m，楼下房间的高度为 0.5 –1.5 米。当X射线束到评价点的水平距离超过3 m且评价点时，通过提出的分析方法计算的楼下房间的有效X射线剂量与蒙特卡罗模拟之间的差异小于25%设置在房间高度的一半。新的分析方法可以高效准确地应用于有效剂量的计算。