A detector system for a high-energy phase-contrast human computed tomography experimental device

A detector system is designed for a high-energy phase-contrast computed tomography (CT) experimental device with an X-ray tube voltage of 80 kV. The spot size of the X-ray tube is 0.4 mm*0.7 mm. The Gd2O2S scintillator detector is adopted in our design, which is characterized by a high detection efficiency and high light yield. This system contains 2304 channels and the corresponding high-density read-out electronics. Considering the influence of the large spot size of the X-ray tube source, a detector pixel size of 0.75 mm*1 mm is adopted to obtain sufficient spatial resolution. Because the light intensity fluctuation caused by the phase shift is very weak, a 20bit ADC is used to achieve sufficient efficient resolution (ER). The electronics test shows that the SNR can reach 72. Compared to a commercial detector board, the detector system has better resolution for the sample used in the phase-contrast imaging experiment.