A sensitive method for Sr-90 analysis by accelerator mass spectrometry |
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Authors: | Kimikazu Sasa Seiji Hosoya Tsutomu Takahashi Kenta Takano Yuta Ochiai |
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Affiliation: | 1. Accelerator Mass Spectrometry Group, Tandem Accelerator Complex, University of Tsukuba , Tsukuba, Ibaraki, Japan ksasa@tac.tsukuba.ac.jp;3. Accelerator Mass Spectrometry Group, Tandem Accelerator Complex, University of Tsukuba , Tsukuba, Ibaraki, Japan;4. Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology , Takasaki, Gunma, Japan;5. Accelerator Mass Spectrometry Group, Tandem Accelerator Complex, University of Tsukuba , Tsukuba, Ibaraki, Japan |
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Abstract: | ABSTRACT Strontium-90 is one of the most important fission products due to the potential health risks of its uptake and retention in the human body. Conventional analysis techniques involve β counting, which requires ingrowth of 90Y over a period of two weeks. Accelerator mass spectrometry (AMS) has the potential to shorten the analysis time while offering a lower limit of detection than β counting. Here, Sr in samples was recovered as SrF2 to provide sufficient negative ions in the caesium-sputtering ion source. In the sample preparation step, 95–98% of Sr was recovered and 99–100% of Zr removed by ion-exchange separation. Sr recovery was ~30% in the precipitation process, and this can be improved. A maximum 500 nA beam current of SrF3 – ions was obtained from SrF2 samples mixed with PbF2. A five-anode gas ionization detector was used to avoid isobaric interference from 90Zr. The 90Sr/Sr atomic ratio background of ~6 × 10–13 (~3 mBq 90Sr) was comparable with that achieved at other AMS facilities. Good linearity in 90Sr/Sr atomic ratios was obtained from 1.75 × 10–10 to 3.38 × 10–9. Suitable techniques for sample preparation and measurement were thus achieved for 90Sr analysis by AMS. |
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Keywords: | 90Sr analysis accelerator mass spectrometry SrF3 – SrF2 preparation IAEA proficiency test solution |
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