  An innovative X-ray imaging sensor with intrinsic digital characteristics is
presented. It is based on Chromatic Photon Counting technology. The detector is
able to count individually the incident X-ray photons and to separate them
according to their energy (two 'color' images per exposure). The energy
selection occurs in real time and at radiographic imaging speed (GHz global
counting rate). Photon counting, color mode and a very high spatial resolution
(more than 10 l.p./mm at MTF50) allow to obtain an optimal ratio between image
quality and absorbed dose. The individual block of the imaging system is a
two-side buttable semiconductor radiation detector made of a thin pixellated
CdTe crystal (the sensor) coupled to a large area VLSI CMOS pixel ASIC. 1, 2,
4, 8 tile units have been built. The 8 tiles unit has 25cm x 2.5cm sensitive
area. Results and images obtained from in depth testing of several
configurations of the system are presented. The X-Ray imaging system is the
technological platform of PIXIRAD Imaging Counters s.r.l., a recently
constituted INFN spin-off company.
