Design and characteristics of a novel single-plane Compton gamma camera based on GAGG scintillators readout by SiPMs

Abstract

We designed a novel, compact, single-plane Compton gamma camera based on GAGG:Ce scintillators read out by silicon photomultipliers. The Compton gamma camera comprises the scatterer and the absorber layers consisting of 8x8 arrays of 3 mm x 3 mm x 3 mm GAGG:Ce pixels. The individual pixels in the scatterer layer are optically coupled to the corresponding pixels in the absorber by the matching 3 mm x 3 mm x 20 mm plexiglass lightguides, and hence both the scatterer and the absorber pixel in one column are readout by the same SiPM. We present the first results of the measured characteristics of the detector. The average energy resolution at 662 keV of the front and the back GAGG:Ce layer is found to be 8.9% ± 1.9% and 10.8% ± 1.6%, respectively. The Compton events are reconstructed based on kinematic conditions and detector geometry and the first image of a 662 keV gamma source is reconstructed using a simple back projection algorithm.