Location and identification of radioactive material with the GRETA (Gamma-Ray Experimental Telescope Assembly)

We previously reported Compton imaging measurements of 137 Cs and 60 Co laboratory sources using the full 15-channel readout of the Gamma-Ray Experimental Telescope Assembly (GRETA). We have since modified the detector geometry to accommodate a wider range of Compton scattering angles and implemented a neural networking method for the location of interaction positions with a 3-cm resolution inside the detector volumes. This paper describes the implementation of the neural networking method and culminates in the imaging of 137 Cs, 60 Co, and 252 Cf sources using this technique.