抽气碰撞法回收擦拭样品上铀微粒方法

Vacuum Suction-Impact Collection for Recovering Uranium Particles From Swipe Sample

摘要: 建立了一种回收微粒的新方法——抽气碰撞法。擦拭布上的铀微粒通过抽气碰撞装置回收到导电胶上，用于二次离子质谱仪（SIMS）对微粒的同位素丰度比测量。使用扫描电镜（SEM）寻找和统计擦拭布和导电胶上的微粒数目，计算装置的回收率。该装置对核孔膜上直径为0.5～20.0 μm的铅微粒回收率为(43±5)%，擦拭布上铀微粒回收率约为48%，回收微粒的分散性好。制备的样品可直接用于SIMS测量，SIMS对²³⁵U与²³⁸U同位素丰度比的测量值为0.007 25±0.000 09，测量标准偏差小于3%。

Abstract: A new particle recovery method from safeguards swipe samples was developed for subsequent isotope ratio analysis of uranium particles by secondary ion mass spectrometry （SIMS）. The particles were determined and counted by scanning electron microscope(SEM). The recovery efficiency is about (43±5)% for PbO particles and about 48% for uranium particles respectively. The dispersion of recovery particles is satisfied. The samples prepared by this method were measured by SIMS. The average isotope ratio of ²³⁵U/²³⁸U for individual natural uranium particles is 0.007 25±0.000 09 with a standard deviation less than 3%.