基于有限点源的航空核辐射沾染场实拟方法研究
Study on Simulation Method of Airborne Nuclear Radiation Contamination Field Based on Finite Point Source

为建立大范围航空核辐射沾染场实验平台，本文提出一种基于点源的无限大面源模拟方法。利用蒙特卡罗模拟软件，建立点源距离–探测效率响应函数，将无限大面源以网格划分，基于积分中值定理，建立点源–圆形线源–网格面源的等效转换函数，以此为基础，建立等效点源分布模型。蒙卡模拟结果表明：探测器对等效点源分布模型和无限大均匀面源的全能峰响应相对误差为1.10%；物理实验结果表明：探测器对等效点源分布模型和无限大均匀面源的全能峰响应相对误差为1.79%。
In order to establish an experimental platform of large-scale nuclear radiation contamination field for airborne radiation measurement, an infinite surface source simulation method based on point source is proposed in this paper. Monte Carlo simulation software was used to establish the point source range-detection efficiency response function, and the infinite surface source was divided into grids. Based on the integral mean value theorem, the equivalent conversion function of point source-circular line source-grid was established. On this basis, the equivalent point source distribution model was established. Results obtained by the Monte Carlo simulation show that the relative deviation between the total peak response of the detector through the equivalent point source distribution model and the infinite uniform surface source is 1.10%, and the experimental results show that the relative deviation between the total peak response of the detector through the equivalent point source distribution model and the infinite uniform surface source is 1.79%.