This instrument has very high mass resolution and sensitivity and is particularly suited to trace element analysis and thus to the individualization of certain kinds of samples. The Cameca instrument is usually termed an ion microprobe , because it can actually display images showing the distribution of specific masses on a specimen with sub-micron spatial resolution. Bullet individualization is one potentially interesting, novel application for SIMS in forensic science.
Bullets often deform or fragment upon impact.
However, lead is one of several elements in which the isotopic composition is not constant. The isotopic variability of lead results because the elements from which these isotopes form were not evenly distributed in ore bodies. The ion microprobe can measure lead isotope ratios and can at the same time measure the concentrations of trace elements in even very small bullet fragments. The first study of the use of lead isotope analysis to individualize bullets was carried out at The Aerospace Corporation by Dr. Gary Stupian. However, several additional papers have been published that support the conclusions drawn in the original Aerospace effort.