测定γ辐射仪自然底数的方法

本文讨论了三种测定γ辐射仪自然底数的方法:水面法、铅屏法和水中法。理论及实验指出,目前国内外广泛使用的水面法和铅屏法难于获得正确的自然底数,指出了其错误之处,并给出了解决这些问题的途径。结果证明,本文提出的水中法是一种简单有效测定γ辐射仪自然底数的方法。只要水域直径在3 m以上,水深2 m,水中的放射性物质微弱,用此法可得到相当近似的自然底数。

DETERMINATION OF THE NATURAL BACKGROUND OF GAMMA-RAY RADIOMETERS

In this paper,three methods for determining the natural background of Υ-radiometers are studied: the methods of water-surface,lead-screen and submersion. Theoretical analysis and experiments prove it difficult to determine the right background with the first two methods,which are widely used in China,and also abroad. Their faults are pointed out and improved methods are given. The results show that the submersion method,offered by the author,is simple and effective to determine the natural background. In this way,a close approximation to the real value can be obtained when the diameter of water area is over 3 meters,its depth is about 2 meters,and it contains little radioactive material.