Directional isotope identification using 3-D semiconductor gamma-ray-imaging spectrometers

Using three-dimensional-position-sensitive semiconductor detectors, our research group has demonstrated the ability to record multiple interaction locations and associated energy depositions due to incident gamma-rays in a pixellated CdZnTe (CZT) detector. These interaction locations and energies can be used to reconstruct a 4¿ image of radiation sources around the detector. We have previously demonstrated gamma-ray imaging techniques which provide an estimate of the incident spectrum in each direction. One can use these spectra for directional identification of the source present in each direction. The performance of identification for two different simultaneous sources in different directions will be shown as a function of source intensity.