کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1822051 | 1526299 | 2016 | 5 صفحه PDF | دانلود رایگان |
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/mm2 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/mm2, 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 nonparalyzable dead time τn for 150 evaluated detector elements is estimated to be 20.2±5.2 ns.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 827, 11 August 2016, Pages 102–106