Multiple Module Pixellated CdTe Spectroscopic X-Ray Detector

• Published in: IEEE transactions on nuclear science 2013-04, Vol.60 (2), p.1197-1200
• Main Authors: Wilson, M. D., Bell, S. J., Cernik, R. J., Christodoulou, C., Egan, C. K., O'Flynn, D., Jacques, S., Pani, S., Scuffham, J., Seller, P., Sellin, P. J., Speller, R., Veale, M. C.
• Format: Article
• Language: English
• Subjects: Application specific integrated circuits; Arrays; CdTe; CdZnTe; Data acquisition; Detectors; Image edge detection; Image quality; Imaging; spectroscopic; X-ray detector
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2013.2240694

A pixellated CdTe detector system comprising 2×2 detector modules has been developed for high energy spectroscopic X-ray imaging applications and has an active area of 16 cm 2 . The detector modules are made from the HEXITEC 80×80 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 80×80 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 2×2 detector array is 2.0 keV at 59.9 keV. The spacing between the tiled detector modules is 150 μm 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.