Fundamentals of accelerator mass spectrometry

Abstract

Abstract The extension of high-sensitivity mass spectrometry to isotope ratios in the range 10-12- 10-15 has been called accelerator mass spectrometry (AMS) because of the use of an additional stage of acceleration that facilitates the removal of molecular interferences and the separation of isobars. In some cases the ultra-high sensitivity is obtained by exploiting the instability of the negative ion of the interfering isobar. It is now possible to measure such isotopes as 14C at natural abundances as low as one atom in 10+1512C atoms. The ideas behind this significant extension of mass spectrometric techniques will be discussed.