1：Experimental Design and Method Selection:

The study designed a Compton camera prototype with two position-sensitive detectors (scatterer and absorber layers), a data acquisition system, and an image reconstruction system. The detectors use Ce-doped Gd3Al2Ga3O12 scintillator arrays coupled to Si-PM arrays. The DAQ system employs symmetric charge division circuit (SCDC), impedance bridge circuit (IBC), and a delay coincidence algorithm to process signals and record coincidence events. Image reconstruction uses simple back-projection (SBP) and list-mode maximum likelihood expectation maximization (LM-MLEM) algorithms, with coordinate of longitude and latitude for image fusion.

2：Sample Selection and Data Sources:

Laboratory tests were conducted using radioactive point sources such as 137Cs and 22Na to evaluate the system's performance.

3：List of Experimental Equipment and Materials:

Equipment includes array SiPM-based detectors (with Ce: GAGG scintillator arrays and Si-PM arrays), DAQ system components (e.g., amplifiers, comparators, FPGA), and a fisheye lens for optical imaging. Materials include Ce: GAGG scintillators, Si-PMs (MicroFC-60035), and reflective layers like BaSO

4：Experimental Procedures and Operational Workflow:

The system was set up with detectors spaced 25 mm apart. Coincidence events were recorded using the DAQ system, with energy and position data processed. Imaging tests involved placing sources at various positions and distances, recording events, and reconstructing images using SBP and LM-MLEM algorithms. Optical images were fused using latitude-longitude projection.

5：Data Analysis Methods:

Data analysis included calculating interaction positions and energies from charge signals, evaluating performance metrics like angular resolution (ARM), energy resolution, and detection efficiency. Statistical analysis was performed on the reconstructed images to assess accuracy and resolution.