Accelerator mass spectrometry (
AMS) differs from other forms of
mass spectrometry in that it accelerates ions to extraordinarily high
kinetic energies before mass analysis. The special strength of AMS among the mass spectrometric methods is its power to separate a rare isotope from an abundant neighboring mass ("abundance sensitivity", e.g.
14C from
12C). The method suppresses molecular isobars completely and in many cases can separate atomic
isobars (e.g.
14N from
14C) also. This makes possible the detection of naturally occurring, long-lived radio-isotopes such as
10Be,
36Cl,
26Al and
14C. Their typical isotopic abundance ranges from 10
-12 to 10
-18. AMS can outperform the competing technique of decay counting for all isotopes where the half-life is long enough.