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

A new analytical method, using SnF₂ target and extracting SnF₃^- 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 SnF₃^- 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.