【摘要】 采用多级撞击采样法对某涉核场所的气溶胶粒径-活度谱进行了分析与研究。发现气溶胶粒径-活度谱呈双峰形分布,活度分别在0.3 μm和5 μm粒径附近达到极大值,1.3 μm附近为极小值。根据TEM和EDX分析结果可以推断:粒径-活度谱呈双峰形分布的原因与现场环境中气溶胶性质和组分密切相关,多个小颗粒结合形成稍大粒径的颗粒,这些稍大粒径的颗粒表现出另一个活度分布的峰形。在最易穿透粒径0.3 μm附近的活度分布对于内照射剂量评价具有重要意义。更多还原

【Abstract】 Using multiple impactor sampler,the relationship between aerosol diameter and activity had been investigated in a facility of processing nuclear materials.It was shown that the shape of size-activity spectrum was double—peaks.Two peaks were around 0.3 μm and 5 μm respectively.Between two peaks,the valley point of activity was found at 1.3 μm.According to the results by TEM and EDX,the special component and characteristics of aerosol particles might lead to the double-peaks.Several small aerosol particles attached together become a bigger particle.Then those bigger particles contribute to another peak appeared.The distribution of activity around 0.3 μm, the best penetration size,can be used for internal irradiation dose estimation of artificial radioactive aerosol.更多还原