Simulation and detector response for the High Efficiency Multimode Imager

The High Efficiency Multimode Imager (HEMI) is a gamma-ray detection system consisting of two planes of CdZnTe detector elements to allow for both coded aperture and Compton imaging of radioactive sources. The HEMI detector is being developed to detect, characterize, and locate gamma-ray sources within the energy range of tens of keV to a few MeV. This paper details the methods used to make accurate simulations and performance predictions and provides an overview of the data analysis pipeline for imaging sources. Compton mode reconstruction and detector response results of simulations and measurements are shown for a 24-detector HEMI array.