Count rate performance of a silicon-strip detector for photon-counting spectral CT
2016 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 827, 102-106 p.Article in journal (Refereed) PublishedText
A silicon-strip detector is developed for spectral computed tomography. The detector operates in photon counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we evaluate the count-rate performance of the detector in a clinical CT environment. The output counts of the detector are measured for x-ray tube currents up to 500 mA at 120 kV tube voltage, which produces a maximum photon flux of 485 Mphotons/s/mm(2) for the unattenuated beam. The corresponding maximum count-rate loss of the detector is around 30% and there are no saturation effects. A near linear relationship between the input and output count rates can be observed up to 90 Mcps/mm(2), at which point only 3% of the input counts are lost. This means that the loss in the diagnostically relevant count rate region is negligible. A semi-nonparalyzable dead-time model is used to describe the count-rate performance of the detector, which shows a good agreement with the measured data. The non-paralyzable dead time tau(n) for 150 evaluated detector elements is estimated to be 20.2 +/- 5.2 ns. (C) 2016 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 827, 102-106 p.
Spectral CT, Photon-counting detector, Silicon-strip detector, Count-rate performance
IdentifiersURN: urn:nbn:se:kth:diva-189065DOI: 10.1016/j.nima.2016.04.087ISI: 000376888900014ScopusID: 2-s2.0-84966709675OAI: oai:DiVA.org:kth-189065DiVA: diva2:943776
QC 201606282016-06-282016-06-272016-09-08Bibliographically approved