Preliminary results of a Compton camera based on a single 3D position-sensitive CZT detector

A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels. Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source. The angular resolution of the 662keV line is 36 degrees FWHM for the simple back-projection method and 9.6 degrees FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.