Status of the High Efficiency Multimode Imager

The High Efficiency Multimode Imager (HEMI) is an instrument to detect, locate, and spectroscopically characterize radioactive sources with gamma-ray emissions at long-range standoff distances. HEMI consists of modular cubic-centimeter coplanar-grid CdZnTe detector elements configured in a two-plane array that allows for both Compton scattering and coded aperture imaging. Measurements and simulations have been performed using a variety of radioactive sources at different positions with respect to a prototype HEMI array in order to demonstrate the source identification and localization capabilities of the system. This paper will provide an overview of the HEMI instrument as well as present results from simulations and measurements using the completed detector array.