Multi-energy X-ray imaging with linear CZT pixel arrays and integrated electronics

We have developed an X-ray image scanning detector system named NEXIS^TM with multi-energy capability that represents significant improvements over a previous version developed for automated baggage screening. The system is built around a 1 mm pitch CZT pixel detector array and a new 32-channel signal processor chip called the XENA^TM IC The CZT array and XENA IC together enable X-ray detection at photon fluxes exceeding one million events per second per channel, at up to five energy levels with medium energy resolution. In the NEXIS system, the detectors are abutted to form a seamless 128 mm long linear array on each detector module board. Up to sixteen boards can be tiled together to form scanning arms of various lengths. The board can also accommodate the use of 0.5 mm pixel pitch linear arrays. Multi-energy-bin images of compositionally and geometrically diverse objects have been acquired to demonstrate materials recognition via energy discrimination and image enhancement by suppression of scattered lower-energy radiation. Applications of this multi-energy x-ray imaging system include security screening, medical imaging and industrial inspection.