为了研究不同形状的防辐射屏自发辐射对探测器的影响并找出影响最小的防辐射屏形状, 采用理论计算对抛物面、双曲面、半椭球面(含半球面)、台柱面(含圆柱面和圆椎面)的防辐射屏内屏自发辐射至探测器的功率进行了系统分析。结果表明, 各种形状防辐射屏自发辐射至探测器的功率随防辐射屏高度与底面半径比值的增大而先减小再增大, 其中最大值为与探测器尺寸相关的常数, 最小值出现在防辐射屏高度与底面半径接近或相等时; 当防辐射屏为半椭球面且高度和底面半径相等(即半球面)时, 自发辐射至探测器的功率小于其它任何形状的防辐射屏, 且与防辐射屏尺寸及顶部开小孔与否无关。本研究能为防辐射屏结构设计提供有价值的参考。

In order to clarify the influence of the spontaneous radiation of different-shape shields on detectors and find out the shape that has the least impact, the spontaneous power to the detector from the inner shields with different shapes was systematically analyzed by theoretical calculation. The shapes of the shields include paraboloid, hyperboloid, semi-ellipsoid (including hemisphere), and frustum of cone (including cylinder and cone). The results showed that the spontaneous power to the detector of all shapes of shields first decreases and then increase with the increase of the ratio of the height of the shield to the radius of the bottom. The maximum radiation power is a constant related to the size of the detector, and the minima appear when the heights of the shields are close to or equal to the radiuses of the bottoms. When the shield is semi-ellipsoidal and the height is equal to the radius (i.e., hemisphere), the power of spontaneous radiation to the detector is less than that of any other shield, and it has nothing to do with the size of the shield or whether there are small holes on the top. This study can provide a valuable reference for the design of radiation shields.