Novel Prototype of a Compton Camera Based on a Monolithic GAGG Crystal

raditional scintillator-based or semiconductor-based Compton Cameras generally use the method of pixelation detector to obtain the interaction position of γ-rays with detectors, which suffers from the disadvantages of complex process, high cost, strong dependence on pixelation size for position resolution, and huge electronic readout system.These disadvanteages limit the development of miniaturization and commercialization of Compton Cameras. In this study, we used the whole GAGG crystal coupled Silicon Photomultiplier (SiPM) array to build two types of detectors, which are Side-readout type detector and Back- readout type detector, and developed two kinds of position reconstruction algorithm, the Response Function Method and the Photon Distribution Reconstruction Method. The position resolution of the two types of detectors was evaluated, and the position resolution of the Side-readout type detector and Back- readout type detector was 1.2 mm and 1.6 mm, respectively. In addition, we built a prototype of a double-layer Compton Camera based on a monolithic GAGG crystal using a Side-readout type detector as a scattering detector and a Back- readout type detector as an absorption detector. The position resolution of locating the radioactive source is 5.4 mm with the source placing 27 mm away from the scattering detector.