用质谱计分析低丰度铀同位素,除要求仪器应具有足够的分辨本领和足够的丰度灵敏度外,减小杂质影响和测量条件的选择,也是精确测量的重要因素。本工作用热电离源质谱计,选用适宜的测量条件,采用法拉第筒与电子倍增器两种测量方式相结合的办法,对辐照燃料样品中的低丰度铀同位素进行了分析。 Mass spectrometry analysis of low abundance uranium isotopes, in addition to requiring the instrument should have sufficient resolution skills and adequate abundance sensitivity, reduce the impact of impurities and the choice of measurement conditions, but also accurate measurement of the important factors. This work using thermal ionization mass spectrometer, select the appropriate measurement conditions, the use of Faraday tube and electron multiplier two ways to combine the measurement of irradiated fuel samples of low abundance uranium isotopes were analyzed.