Characterization of a silicon strip detector for photon-counting spectral CT using monoenergetic photons from 40 keV to 120 keV
2014 (English)In: Medical Imaging 2014: Physics of Medical Imaging, SPIE - International Society for Optical Engineering, 2014, 90333O- p.Conference paper (Refereed)
Background: We are developing a segmented silicon strip detector that operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we determine the energy resolution of the detector using monoenergetic x-ray radiation from 40 keV to 120 keV. We further investigate the effects of pulse pileup and charge sharing between detector channels that may lead to a decreased energy resolution. Methods: For each incident monochromatic x-ray energy, we obtain count spectra at different photon fluxes. These spectra corresponds to the pulse-height response of the detector and allow the determination of energy resolution and charge-sharing probability. The energy resolution, however, is influenced by signal pileup and charge sharing. Both effects are quantified using Monte Carlo simulations of the detector that aim to reproduce the conditions during the measurements. Results: The absolute energy resolution is found to increase from 1.7 to 2.1 keV for increasing energies 40 keV to 120 keV at the lowest measured photon flux. The effect of charge sharing is found to increase the absolute energy resolution by a factor of 1.025 at maximum. This increase is considered as negligibly small. The pileup of pulses leads to a deterioration rate of the energy resolution of 4 · 10-3 keV Mcps-1 mm2, corresponding to an increase of 0.04keV per 10 Mcps increase of the detected count rate.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2014. 90333O- p.
, Progress in Biomedical Optics and Imaging, ISSN 1605-7422 ; 9033
energy resolution, photon counting, pulse pileup, silicon strip detector, spectral CT
Radiology, Nuclear Medicine and Medical Imaging
IdentifiersURN: urn:nbn:se:kth:diva-146702DOI: 10.1117/12.2042862ISI: 000338775800127ScopusID: 2-s2.0-84901611429ISBN: 978-081949826-7OAI: oai:DiVA.org:kth-146702DiVA: diva2:724873
Medical Imaging 2014: Physics of Medical Imaging; San Diego, CA; United States; 17 February 2014 through 20 February 2014
QC 201406132014-06-132014-06-132014-09-08Bibliographically approved