A method for measurement of ultratrace Se-79 with accelerator mass spectrometry

作者：Wang, Wei^*; Guan, Yongjing; He, Ming; Jiang, Shan; Wu, Shaoyong; Li, Chaoli

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2010, 268(7-8): 759-763.

DOI：10.1016/j.nimb.2009.10.024

• Se-79
• Isobar suppression
• Detection
• Ag2SeO3
• Gas ionization chamber
• Accelerator mass spectrometry (AMS)

Se-79 is a long-lived fission product with chemical and radiological toxicity. It is one of the radionuclides of interest in nuclear waste disposal due to its potential migration capacity to the surface environment. Furthermore, Se-79 is an ideal tracer in biomedicine. One of the major obstacles in the measurement of ultratrace Se-79 with AMS is the strong interference from the isobaric nuclide Br-79. This paper presents a new ultra-sensitive method for Se-79 measurements with AMS. The novel aspects of our procedures include the extraction of SeO2- molecular ions, that results in a suppression of Br-79 background by as much as about five orders of magnitude; the selection of Ag2SeO3 as the chemical form of Se in the target sample, that brings about a relatively large and stable SeO2- beam current; and the renovation of the multi-anode detector, that makes Se-79 better identified from the interfering nuclide Br-79. By using these procedures, a sensitivity of better than 1.0 x 10(-12) has been achieved for Se-79/Se measurement with the CIAE-AMS system. It is then possible to quantify the tracer Se-79 in biological samples. Recently, we are prepared to develop the Se-79-AMS biological tracer methodology.

• 出版日期2010-4
• 单位广西大学; 中国原子能科学研究院