Study on SiPM GFAG scintillator for high time resolution Compton camera

Compton camera is a radiation detector that uses the kinematics of Compton scattering to estimate the direction of the gamma-ray incident. Compton camera has been used in many applications such as astronomy, medical, nuclear industry, and security. High time resolution in a Compton camera is essential to distinguish the incoming event in the detector. In this work, we developed a Compton camera using a fast decay scintillator and a high time resolution front end circuit to get a high-performance detector. The detector used an 8×8 multi-pixel photon counter (MPPC) array, which individually couple with a 2.5×2.5×5 mm³ GFAG (Gadolinium Fine Aluminum Gallate) scintillator. For processing the analog signal from the MPPC scintillators, the 64 channel ASIC (Application-Specific Integrated Circuit) is used. Each channel in the ASIC circuit consists of a pre-amplifier, shaper, monostable multivibrator, and slew-rate time over threshold. The ASIC will provide the digital output signal that contains the timing and energy information. The high-time resolution data acquisition circuit (PETnet) based on FPGA is used to acquire energy and time data from ASIC.