Isotope Ratio Measurement of Long-Lived Radionuclides

Isotope Ratio Measurement of Long-Lived Radionuclides... 

Instrumental layouts and developments in AMS are reviewed by Kutschera.195 Today AMS is the most powerful, sensitive and selective mass spectrometric technique for measuring long-lived radionuclides at the level of natural isotopic abundances (10-16 to 10-12). Accelerator mass spectrometry (AMS) allows uranium isotope ratio measurements with an abundance sensitivity for 236U in the range of l(rlo-10 l2.l98J"... 

Accelerator mass spectrometry (AMS) - precise measurement of the isotopic ratios of the long-lived radionuclides that occur naturally in our environment are beyond the ability of conventional mass spectrometers. For isotopes that exist as infinitesimal traces (a single atom in the presence of 1x10 stable atoms) there exist worldwide, a network of around 50 mass spectrometers, each derived from Van de Graaff accelerators, which are used for these analyses (Figure 16.28). 

AMS measures the ratio of a long-lived radionuclide to its stable isotope (e.g., C/ C). However, in the case of plutonium, there is no stable isotope. Hence, it is necessary to add a spike of a known amount of one of the long-lived isotopes, generally Pu (3.75 x 10 years) or Pu (2.4 x 10 years), to the sample in order to quantify the concentrations of the... 

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