Multi-Material Decomposition using Low-Current X-Ray and a Photon-Counting CZT Detector

We developed and evaluated an x-ray photon-counting imaging system using an energy-resolving cadmium zinc telluride (CZT) detector coupled with application specific integrated circuit (ASIC) readouts. This x-ray imaging system can be used to identify different materials inside the object. The CZT detector has a large active area (5x5 array of 25 CZT modules, each with 16x16 pixels, cover a total area of 200 mm x 200 mm), high stopping efficiency for x-ray photons (similar to 100 % at 60 keV and 5 mm thickness). We explored the performance of this system by applying different energy windows around the absorption edges of target materials, silver and indium, in order to distinguish one material from another. The photon-counting CZT-based x-ray imaging system was able to distinguish between the materials, demonstrating its capability as a radiation-spectroscopic decomposition system.