Steier P, Hrnecek E, Priller A, Quinto F, Srncik M, Wallner A, Wallner G, Winkler S
VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria.
Nucl Instrum Methods Phys Res B. 2013 Jan;294(2-2):160-164. doi: 10.1016/j.nimb.2012.06.017.
VERA, the Vienna Environmental Research Accelerator, is especially equipped for the measurement of actinides, and performs a growing number of measurements on environmental samples. While AMS is not the optimum method for each particular plutonium isotope, the possibility to measure Pu, Pu, Pu, Pu and Pu on the same AMS sputter target is a great simplification. We have obtained a first result on the global fallout value of Pu/Pu = (5.7 ± 1.0) × 10 based on soil samples from Salzburg prefecture, Austria. Furthermore, we suggest using the Pu/Pu ratio as an estimate of the initial Pu/Pu ratio, which allows dating of the time of irradiation based solely on Pu isotopes. We have checked the validity of this estimate using literature data, simulations, and environmental samples from soil from the Salzburg prefecture (Austria), from the shut down Garigliano Nuclear Power Plant (Sessa Aurunca, Italy) and from the Irish Sea near the Sellafield nuclear facility. The maximum deviation of the estimated dates from the expected ages is 6 years, while relative dating of material from the same source seems to be possible with a precision of less than 2 years. Additional information carried by the minor plutonium isotopes may allow further improvements of the precision of the method.
维也纳环境研究加速器（VERA）特别配备了用于测量锕系元素的设备，并对环境样品进行越来越多的测量。虽然加速器质谱法（AMS）并非对每种特定钚同位素的最佳测量方法，但能够在同一AMS溅射靶上测量钚-238、钚-239、钚-240、钚-241和钚-242是极大的简化。我们基于奥地利萨尔茨堡州的土壤样本，首次得到钚-240/钚-239的全球沉降值为(5.7 ± 1.0) × 10 。此外，我们建议使用钚-240/钚-239比值来估算初始钚-240/钚-239比值，这使得仅基于钚同位素就能确定辐照时间。我们已通过文献数据、模拟以及来自奥地利萨尔茨堡州土壤、意大利塞萨奥伦卡关闭的加里利亚诺核电站和英国塞拉菲尔德核设施附近爱尔兰海的环境样本，检验了该估算的有效性。估算日期与预期年龄的最大偏差为6年，而对同一来源物质的相对定年似乎可以达到小于2年的精度。次要钚同位素携带的额外信息可能会使该方法的精度进一步提高。
