一、引言在铀系元素中,RaB和RaC所放出的γ射线强度占整个铀系元素的90%以上,而γ射线强度又有和放出它的元素的原子数量成正比的特性。所以这就使得有可能通过测量矿石样品的γ射线强度来求其中的镭含量。RaB和RaC的半衰期很短,经过三个小时就能和氡平衡。氡的半衰期较长,为3.825日,它和镭达到平衡需要经过一个月左右。由于镭衰变寸α粒子的反作用力和气体的扩散性 I. INTRODUCTION In uranium series elements, the intensity of gamma rays emitted by RaB and RaC accounts for more than 90% of the total amount of uranium series elements, and the intensity of gamma rays is in turn proportional to the atomic number of the elements emitting it. This therefore makes it possible to find the radium content in the ore by measuring its gamma-ray intensity. The short half-life of RaB and RaC balances radon over a three-hour period. Radon has a long half-life of 3. 825 days and it takes about a month to reach equilibrium with radium. As a result of the decay of radium α particle reaction force and gas diffusion