Speaker
Matthew Veale
(STFC Rutherford Appleton Laboratory)
Description
Over the last 10 years STFC have developed a range of small pixel spectroscopic imaging detectors based on Cadmium Telluride (CdTe) and Cadmium Zinc Telluride (CdZnTe) materials [1]. These detectors consistently produce excellent spectroscopic performance with greater than 98 % of pixels having a FWHM of 1 keV or better at 60 keV [2]. These detectors are now in use in a number of different application areas including materials science [3], homeland security [4] and medical imaging [5].
In this paper results are presented from the characterisation of 25 CdTe detectors with aluminium pixelated Schottky anodes. Each 1 mm thick detector consists of an array of 80 x 80 pixels on a 250 micron pitch that is flip-chip-bonded to the Hexitec spectroscopic ASIC [6]. Each of the 6,400 pixels of the detector produce a high resolution X-ray spectrum in the energy range 2-200 keV.
Using sealed radiation sources, the effects of bias voltage and operating temperature on the spectroscopic performance, stability and uniformity of these detectors will be characterised. Non-uniformities in the detector responses will also be investigated and related to the presence of crystal defects such as tellurium inclusions, dislocation walls and grain boundaries.
[1] S. D. M. Jacques, C. K. Egan, M. D. Wilson, M. C. Veale, P. Seller & R. J. Cernik. “A laboratory system for element specific hyperspectral imaging”, Analyst, 138 (3), 755-759, 2013. http://dx.doi.org/10.1039/C2AN36157D
[2] M. C. Veale, S. J. Bell, P. Seller, M. D. Wilson & V. Kachkanov. “X-ray micro-beam characterization of a small pixel spectroscopic CdTe detector”, Journal of Instrumentation, P07017, 2012. http://dx.doi.org/10.1088/1748-0221/7/07/P07017
[3] C. K. Egan, S. D. M. Jacques, T. Connolley, M. D. Wilson, M. C. Veale, P. Seller & R. J. Cernik. “Dark-field hyperspectral X-ray imaging”, Proceedings of the Royal Society A Mathematical, Physical and Engineering Sciences, 270 (2165), 20130629, 2014. http://dx.doi.org/10.1098/rspa.2013.0629
[4] D. O’Flynn, H. Desai, C. B. Reid, C. Christodoulou, M. D. Wilson, M. C. Veale, P. Seller, D. Hills & B. Wong. “Identification of simulants for explosives using pixelated X-ray diffraction”, Crime Science, 2 (4), 2013. http://dx.doi.org/10.1186/2193-7680-2-4
[5] J. W. Schuffham, M. D. Wilson, P. Seller, M. C. Veale, P. J. Sellin, S. D. M. Jacques & R. J. Cernik. “A CdTe detector for hyperspectral SPECT imaging”, Journal of Instrumentation, P08027, 2012. http://dx.doi.org/10.1088/1748-0221/7/08/P08027
[6] L. L. Jones, P. Seller, M. D. Wilson & A. Hardie. “HEXITEC ASIC – a pixelated readout chip for CZT detectors”, Nuclear Instruments and Methods in Physics Research A, 604 (1-2), 34-37, 2009. http://dx.doi.org/10.1016/j.nima.2009.01.046
Primary author
Matthew Veale
(STFC Rutherford Appleton Laboratory)
Co-authors
Dr
Andreas Schneider
(STFC Rutherford Appleton Laboratory)
Ms
Diana Duarte
(STFC Rutherford Appleton Laboratory)
Mr
Matt Wilson
(STFC Rutherford Appleton Laboratory)
Mr
Paul Seller
(STFC Rutherford Appleton Laboratory)
Mr
Steven Bell
(STFC Rutherford Appleton Laboratory)
