Design of a high-resolution gamma-ray detector module for tomography applications

We present a modular gamma-ray detector design for gamma-ray tomography applications. As a key electronic component we use the APD array S8550 of Hamamatsu Corp. with 4×8 single APD elements each of 1.6 mm×1.6 mm size. For this APD array we tested and evaluated different configurations of 2 mm wide lutetium yttrium orthosilicate scintillation crystals. Emphasize was given to high counting efficiency and low dead time in order to secure applicability of the detector to tomography of objects with highly attenuating materials. For electronic processing, we designed a low-cost low-power charge-sensitive preamplifier circuit using commercially available operational amplifier ICs. The modular design of the detectors allows us to build up larger line or arc detectors.