Energy distribution of secondary organic ions

The energy distribution of secondary organic ions is analyzed in relation to various parameters important for secondary ion mass spectrometry (SIMS) and fast-atom bombardment (FAB) experiments. The difference in the high-energy tails of peaks from organic ions compared with inorganics suggested that a direct knock-on mechanism plays a more important role with inorganics than with organic molecules. Application of the energy analyser as a selector for sample ions in SIMS/FAB experiments and a supressor for a matrix is demonstrated.