Photon counting X-ray imaging with CdTe pixel detectors based on XPAD2 circuit

摘要

A semiconductor hybrid pixel detector for photon counting X-ray imaging has been developed and tested under radiation. The sensor is based on recent uniform CdTe single crystal associated with XPAD 2 counting chip via innovative processes of interconnection. The building detector is 1 mm thick, with an area of 1 cm(2) and consists of 600 square pixels cells 330 pm side. The readout chip working in electron collection mode is capable of setting homogeneous threshold with only a dispersion of 730 e(-). Maximum noise level has been evaluated around 15 keV. First experiments under X-rays demonstrate a very good efficiency of detection. Moreover, imaging system allows excellent linearity over a large-scale achieving count rate of 3 x 10(6) photons/s/mm(2). Spectrometric measurements point up the system potential in multi-energies applications by locating and resolving X-rays lines of Am-241 and Co-57 sources. (c) 2006 Elsevier B.V. All rights reserved.