γ针孔照相测量放射性污染分布

A γ-pinhole camera for locating contamination in hot cells

介绍了一种测量设备γ放射性表面污染的新方法．利用γ射线的直线传播和与物质相互作用的特性，采用针孔成像原理，以２３８Ｕ作为针孔材料，通过模拟计算得到针孔的设计参数，并据此制作一视场角为６０°的针孔相机．利用此相机分别对γ污染源和污染设备成像，经计算机处理，将此二幅图像叠加起来，可以清楚地知道污染源在设备上的位置及其在相机处产生的剂量水平．该方法具有直观、清晰、工作人员受辐射剂量少的优点，测量结果可以以图像方式保存．经模拟实验，其结果令人满意．

new method to monitor the surface contamination on some devices in hot cells is presented. According to the straight propagation of γ rays, their interaction with materials, and the pinhole imaging principle, a pinhole camera, made of 238U material, was developed. With this camera, both contaminations on the device and the device itself can be imaged. Overlapping of the two photos by a computer will give a new picture, which can tell both distribution and intensity of the contaminations. This method ensures a more direct and clear γ-contamination monitoring, and a less exposure dose to the monitoring workers.