摘要
中国辐射防护研究院(China Institute for Radiation Protection,CIRP)引进一台300 kV多核素低能加速器质谱仪(Multi-Isotope Low-Energy Accelerator mass spectrometry,MILEA),可用于各种基体样品中超低含量的^(14)C、^(129)I和锕系核素(Pu同位素、^(237)Np、Am同位素、Cm同位素及U同位素)的测量。在对该系统进行现场验收及调试测量中,通过对稳定核素从低能端到高能端的传输效率及高能端的电流强度、空白样品中稀有放射性核素与其稳定核素的比值及丰度灵敏度、标准样品中单个样品及多个样品测量的弥散度等关键参数的测试,结果显示:^(14)C/^(12)C最小比值为(1.3±0.1)×10^(-15),测量精度为0.2%;WWI^(129)I/127I最小比值为(3.76±0.2)×10^(-14),测量^(129)I/127I比值为10-12的样品,测量精度为0.41%;针对超铀核素的测量,239/238的丰度灵敏度为(1.5~2.7)×10^(-13),Pu同位素、^(237)Np和^(244)Cm的最低探测限低至10^(-18)g水平。证明该系统已具备对^(14)C、^(129)I和锕系核素的超灵敏测量能力,所获得的测量水平与高能加速器质谱仪(Accelerator Mass Spectrometry,AMS)系统相比具有竞争力。
[Background]Accelerator Mass Spectrometry(AMS)is a powerful technique for ultra-trace analysis of long-lived radionuclides whilst the performance is the mean concern for practical application.[Purpose]This study aims to evaluate the performance of a 300 kV multi-isotope low-energy accelerator mass spectrometry(MILEA)system installed at the China Institute for Radiation Protection(CIRP)for measuring^(14)C,^(129)I,and actinide nuclides.[Methods]The system was systematically tested through on-site acceptance and tuning measurements.Firstly,the transmission efficiency from the low-energy end to the high-energy end and current intensity were measured for stable isotopes.Then,the ratios of rare radionuclides to stable nuclides and abundance sensitivity were determined using blank samples.Finally,the measurement precision was evaluated by analyzing multiple standard samples.[Results]Measurement results show that the^(14)C/^(12)C blank ratio achieved is(1.3±0.1)×10^(-15).The^(129)I/127I blank ratio in Woodward iodine is(3.76±0.2)×10^(-14).For actinide measurements,the abundance sensitivity of 239Pu/238U is(1.5~2.7)×10^(-13),and the detection limits for Pu isotopes,^(237)Np,and ^(244)Cm reached the 10^(-18)g level.[Conclusions]Evaluation results of this study demonstrate that the CIRP-AMS system achieves excellent performance competitive with larger AMS facilities,making it suitable for ultra-sensitive analysis of^(14)C,^(129)I,and actinide nuclides in various applications.
作者
原妮
邬洋
罗茂益
杨永刚
彭彤
YUAN Ni;WU Yang;LUO Maoyi;YANG Yonggang;PENG Tong(China Institute for Radiation Protection,Taiyuan 030006,China;Shanxi Provincial Key Laboratory of Nuclear Drug R&D,Transformation and Precision Protection,Taiyuan 030006,China;Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions,Soochow University,Suzhou 215006,China)
出处
《核技术》
2026年第4期34-41,共8页
Nuclear Techniques
基金
国家自然科学基金(No.12375317,No.12175201)
山西省中央引导项目(No.YDZJSX2024D078)
中国辐射防护研究院创新团队基金资助。
