Multiple module pixellated CdTe spectroscopic X-ray detector

Abstract

A pixellated CdTe detector system comprising 2x2 detector modules has been developed for high energy spectroscopic X-ray imaging applications and has an active area of 16 cm2. The detector modules are made from the HEXITEC 80x80 ASIC and 1 mm thick CdTe with Al-Schottky contacts. The CdTe has 250 μm pitch pixels with an outer guard ring on the same pitch. The single HEXITEC 80x80 detectors have an average energy resolution (FWHM) of 800 eV at 59.9 keV. Limitations in the multiple module DAQ system mean that the energy resolution of the pixels in the 2x2 detector array is 2.0 keV at 59.9 keV. The spacing between the tiled detector modules is 150 μ m which results in an inactive area equivalent to 3 pixels, including the guard ring on the edge of the detectors. The modular detector configuration demonstrates the potential to create large area detector arrays in the future. © 1963-2012 IEEE.