全景γ参考辐射场中散射辐射的蒙特卡罗模拟

Monte Carlo Simulation of Scattered Radiation of Free-Field Geometries Gama Reference Radiation Field

参考辐射场在辐射监测仪表的检定和校准工作中起着至关重要的作用,辐射场中散射辐射的剂量率是评价辐射场性能的重要指标。利用蒙特卡罗方法对开放和封闭两种几何条件下的γ全景参考辐射场中的剂量率分布情况进行模拟计算,并对辐射场中散射辐射情况进行研究。将封闭几何条件下的计算结果与实验数据比较后建立并完善一套计算全景γ参考辐射场中散射辐射剂量率的蒙特卡罗方法,能够精确计算出辐射场中地面、墙壁和空气等的散射剂量率。结果表明,散射辐射的蒙特卡罗方法研究对实验室内全景结构参考辐射场的设计建造有重要的指导作用。

Reference radiation filed produced by isotope source is necessary for calibration of radiation close meter. Scattered dose is an important characteristic in the reference radiation field. How to reduce the scattered dose is an important research of radiation metrology. Monte Carlo method was used to obtain the dose distribution of open and closed geometries free-field gamma reference radiation field, calculated the scattered dose. The calculation was tested by the results acquired in the Radiation Metrology Center in order to find a Monte Carlo method to study the free-field reference radiation field, the photons scattered in floor, walls, air etc. was also calculated. In addition, the conclusion of this study can al- so do good to the design and construct of the free-field radiation field.