全蒸发技术在铀同位素丰度测量上的应用

采用全蒸发技术、离子流强度积分的方式 ,用多接收器热表面电离质谱计测量铀同位素丰度。全蒸发技术可克服质量分馏效应带来的测量误差 ,而直接实现准确测量。开发了用于全蒸发技术的测量软件 ,对影响测量结果的因素 ,诸如分析用样量、信号损失与试样残留等进行了研究。最后得出在铀同位素丰度比为 0 1～ 10的范围内 ,95 %的置信水平下 ,该方法的相对扩展不确定度为0 10 %

The Application of Total Sample Evaporation Technique in Mass Spectrometric Measurement of Uranium Isotopes

Uranium isotope abundance ratio has been measured by total sample evaporation and signal integration, and a thermal surface ionization mass sepctrometry equipped with multicollector has been used. Total sample evaporation technique can eliminate the influence of mass fractionation, and accuracy measurement is directly achieved without calibration by isotope reference standard materials. Analysis software for total sample evaporation technique has been developed. The factors of interference measurement, such as sample size, signal intensity loss and sample residue, have been studied. Under 0.1～10 isotope ratio range and 95 % confidence, the relative expanded uncertainty of the technique is 0.10%.