α径迹法用于分辨高浓铀和Pu微粒的方法研究

擦拭样品微粒分析技术是核保障环境样品分析的一种主要手段，从大量灰尘颗粒中识别并定位含高浓铀（HEU）或含Pu微粒是微粒分析首先需要解决的问题。本文以HEU和Pu微粒为研究对象，建立了用于微粒α径迹测量的样品制备方法，采用CR-39固体径迹探测器为α径迹探测器，测量了不同蚀刻时间2种微粒产生的α径迹星的径迹参数。结果表明：可通过测量径迹短轴与曲率直径并作图来分辨HEU和Pu微粒，该方法对于蚀刻时间大于10 h的微粒径迹星，均能明显分辨，对于径迹非常密集的径迹星，也能准确分辨。

Identification and Distinguishing of HEU Particle and Pu Particle by α Track Method

The analytical technique of swipe sample particle analysis plays an important role in sample analysis of nuclear safeguard environmental sampling, and the first step of particle analysis is to search highly enriched uranium (HEU)bearing or Pu-bearing particles among dust particles. A new method for identifying HEU and Pu particles was established by using α track detection. First, an organic film containing particles was prepared and covered with a CR-39 solid state nuclear detector. After exposure, the detector was etched in a NaOH solution for different time, and the α track star parameters created by HEU or Pu particles were measured by optical microscope. The results show that the scatter plot of the dimeter of track end versus track minor axis can be used for HEU and Pu particles distinguishing when etching time is lager than 10 h, especially useful when track stars are concentrated.