Neutron Activation Analysis (NAA) is an elemental analysis technique that involves placing a sample in a known neutron flux and observing the radioisotopes that are produced. From the amount and type of radioisotopes produced, the elemental composition of the sample can be determined. NAA is sensitive to up to 74 elements in concentrations of .1 ppm or less typically without requiring chemical processing and only minimal sample preparation. At the MUTR, samples are typically irradiated in the rabbit and after some decay time, counted using a High Purity Germanium Detector.