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天然辐射环境中居民受照剂量一半以上来自氡组,因此快速而准确地测定环境中氡浓度成为辐射防护研究的重要课题。在通常的滤膜抽气过滤法测氡子体中,由于无法假定氡与其子体间的平衡程度,因此不能直接推算氡浓度。因为氡的短寿命子体RaA、RaB、RaC(RaC’)为气载核素,且RaA(~(213)Po)的半衰期最短(3.05min),这就为人们提出了只要采用一定的测量装置和技术,由方法给定的条件计算出RaA与~(222)Rn之间的放射性平衡比m,则测RaA浓度便变为直接测氡浓度。七十年代以来,国内外发展起来的两种快速测
In the natural radiation environment, more than half of the inhabitants receive the radon group dose, so fast and accurate determination of radon concentration in the environment becomes an important issue of radiation protection research. Radon concentration can not be directly calculated in the conventional radon detection by membrane filtration method since the equilibrium between radon and its daughter can not be assumed. Because radon short-lived progeny RaA, RaB and RaC (RaC ’) are airborne nuclides and the shortest half-life of RaA (~ (213) Po) is 3.05min, Devices and techniques, the radiometric equilibrium ratio, m, between RaA and ~ (222) Rn is calculated from the conditions given by the method, then the measured RaA concentration becomes the direct measurement of radon concentration. Since the seventies, two rapid tests developed at home and abroad