Detection Limits of Particles Analyzed by AMS

Long-lived radioisotope analysis is based on the measurement of a very small isotopic ratio. Usually, small amounts of chemically prepared pure samples (in the form of elements or compounds) rather than the original samples are used in the ion source. The element-preconcentration is performed during the preparation of the AMS sample. Since the natural abundances of long-lived radioisotopes are usually very low in terrestrial materials, the contamination by the radioisotope itself from the environment is not a severe problem. The background may come from interferences of atomic and molecular species, stable isobars and isotopes, which can be discriminated effectively by AMS. Consequently, high sensitivities can be achieved in the AMS measurements of the radioisotopes ( °Be, Al, Si, Cl, Ca, etc.) for tracer studies. The 

Accelerator Mass Spectrometry is a special tool for quantitative measurements of very long-lived radionuclides. This technique consists of counting the nuclides themselves instead of waiting for their decay. As for as the tandem accelerator is concerned, no molecular background exists because of the stripping process. Any isobaric background is also drastically suppressed due to the nuclear techniques involved in the measurements. There occurs an extremely wide area of applications in different fields because of the capability of the AMS technique to determine the radioisotopes at the faintest level (the isotopic concentrations down to the range of 10 in some cases). 

The AMS method has been applied in different areas of Science such as archeology, earth science, pollution, biomedicine, hydrology, material science, and geological science. More than one isotope may be used within a given area. Some of the areas of research in which AMS is presently having an impact, are explained in Sects. 8.8.1-8.8.10. 

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