基于SnF2靶样的加速器质谱测量裂变产物126Sn的方法研究

在中国原子能科学研究院HI-13串列加速器质谱系统上建立了以SnF₂为靶样，引出SnF₃^-分子负离子形式的¹²⁶Sn-AMS分析方法。介绍了用于AMS测量的¹²⁶Sn实验室参考标准的研制以及靶物质SnF₂的化学制备过程，通过引束实验确定了可将同量异位素¹²⁶Te本底干扰压低2～3个量级的SnF₃^-分子负离子引出形式，实现了¹²⁶Sn束流的传输以及同量异位素的探测和鉴别。对制备的3个标准样品（¹²⁶Sn/Sn原子个数比为1.033×10^-8、4.54×10^-9、6.43×10^-10）的测量结果显示，¹²⁶Sn/Sn原子个数比测量值与标称值呈良好的线性关系（R²=0.999），通过测量空白样品获得系统探测¹²⁶Sn测量的灵敏度为（1.92±1.13）×10^-10。

Measurement of Fission Product Nuclide 126Sn With Accelerator Mass Spectrometry Based on SnF2 Target

A new analytical method,using SnF2 target and extracting SnF-3 molecular negative ions,was developed at CIAE HI-13 Accelerator Mass Spectrometry System for measurement of 126Sn.The development of the 126Sn calibration standard for AMS measurement and the preparation flow of target materials SnF2 were described in this paper.The results indicate that the extraction ion form SnF-3 can depress the interference of 126Te as much as 2-3 order of magnitude.A perfect linearity(R2=0.999) between measured and nominal 126Sn/Sn atom number ratios was obtained by using three standard samples with 126Sn/Sn atom number ratios of 1.033×10-8,4.54×10-9,and 6.43×10-10.A sensitivity of(1.92±1.13)×10-10(126Sn/Sn) was reached by measuring a blank sample.