Investigating uranium isotopic distributions in environmental samples using AMS and MC-ICPMS

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:259

Article; Proceedings Paper

Buchholz, B. A. ; Brown, T. A. ; Hamilton, T. F. ; Hutcheon, I. D. ; Marchetti, A. A. ; Martinelli, R. E. ; Ramon, E. C. ; Tumey, S. J. ; Williams, R. W.

关键词: uranium isotopes;    U-236;    natural uranium;   

DOI  :  10.1016/j.nimb.2007.01.248

来源: Elsevier

【 摘 要 】

Major, minor and trace uranium isotopes were measured at Lawrence Livermore National Laboratory in environmentally acquired samples using different instruments to span large variations in concentrations. Multi-collector inductively-coupled plasma mass spectrometry (MC-ICPMS) can be used to measure major and minor isotopes: U-238, U-235, U-234 and U-236. Accelerator mass spectrometry (AMS) can be used to measure minor and trace isotopes: U-234, U-236 and U-233. The main limit of quantification for minor or trace uranium isotopes is the abundance sensitivity of the measurement technique; i.e. the ability to measure a minor or trace isotope of mass M in the presence of a major isotope at M +/- 1 mass units. The abundance sensitivity for U-236/U-235 isotope ratio measurements using MC-ICPMS is around similar to 2 x 10(-6). This compares with a U-236/U-235 abundance sensitivity of similar to 1 X 10(-7) for the current AMS system, with the expectation of 2-3 orders of magnitude improvement in sensitivity with the addition of another high energy filter. Comparing U-236/U-234 from MC-ICPMS and AMS produced agreement within similar to 10% for samples at U-236 levels high enough to be measurable by both techniques. (c) 2007 Elsevier B.V. All rights reserved.

【 授权许可】

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