TY - JOUR
T1 - Sensitivity enhancement of an experimental benchtop X-ray fluorescence imaging system by deploying a single crystal cadmium telluride detector system optimized for high flux X-ray operations
AU - Moktan, Hem
AU - Jayarathna, Sandun
AU - Cho, Sang Hyun
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/2/11
Y1 - 2022/2/11
N2 - In this work, an energy-resolving thermoelectrically cooled single crystal cadmium telluride (CdTe) detector system upgraded with the latest firmware was optimized for high X-ray flux operations using high bias voltage and fast peaking time. This detector system was deployed into an experimental benchtop X-ray fluorescence (XRF) imaging/computed tomography (XFCT) system developed for quantitative imaging of metal nanoprobes such as gold nanoparticles (GNPs). Using the firmware-upgraded and existing/old CdTe detector systems, the Compton/XRF spectra from small (8 mm diameter) GNP-containing phantoms were acquired. The phantoms were irradiated with 1.8 mm Sn-filtered 125 kVp cone beam X-rays at 24 mA. The firmware-upgraded detector system produced relatively lower dead time under high X-ray flux, compared with the old detector system, and performed well with the spectral resolution of ∼0.7 keV (in full width at half maximum) at 69 keV photon energy. Given the same 2 mm aperture detector collimator and irradiation time of 10 s, this detector system managed to score nearly 50% more gold XRF signals than the existing one at all GNP concentrations tested. This improvement resulted in the GNP detection limit of 0.02 wt. % which was lower than that (0.03 wt. %) achievable with the existing detector system. When combined with the detector collimator containing a larger (3 mm) aperture, the firmware-upgraded detector system produced drastically more gold XRF signal at a given GNP concentration (e.g., 9 times more for 1 wt. % GNP solution and irradiation time of 10 s), leading to further reduction in the GNP detection limit (i.e., 0.01 wt. %). The present investigation showed that the firmware upgraded CdTe detector system optimized for high X-ray flux operations allowed for better photon counting efficiency, thus leading to sensitivity enhancement of an experimental benchtop XRF/XFCT imaging system.
AB - In this work, an energy-resolving thermoelectrically cooled single crystal cadmium telluride (CdTe) detector system upgraded with the latest firmware was optimized for high X-ray flux operations using high bias voltage and fast peaking time. This detector system was deployed into an experimental benchtop X-ray fluorescence (XRF) imaging/computed tomography (XFCT) system developed for quantitative imaging of metal nanoprobes such as gold nanoparticles (GNPs). Using the firmware-upgraded and existing/old CdTe detector systems, the Compton/XRF spectra from small (8 mm diameter) GNP-containing phantoms were acquired. The phantoms were irradiated with 1.8 mm Sn-filtered 125 kVp cone beam X-rays at 24 mA. The firmware-upgraded detector system produced relatively lower dead time under high X-ray flux, compared with the old detector system, and performed well with the spectral resolution of ∼0.7 keV (in full width at half maximum) at 69 keV photon energy. Given the same 2 mm aperture detector collimator and irradiation time of 10 s, this detector system managed to score nearly 50% more gold XRF signals than the existing one at all GNP concentrations tested. This improvement resulted in the GNP detection limit of 0.02 wt. % which was lower than that (0.03 wt. %) achievable with the existing detector system. When combined with the detector collimator containing a larger (3 mm) aperture, the firmware-upgraded detector system produced drastically more gold XRF signal at a given GNP concentration (e.g., 9 times more for 1 wt. % GNP solution and irradiation time of 10 s), leading to further reduction in the GNP detection limit (i.e., 0.01 wt. %). The present investigation showed that the firmware upgraded CdTe detector system optimized for high X-ray flux operations allowed for better photon counting efficiency, thus leading to sensitivity enhancement of an experimental benchtop XRF/XFCT imaging system.
KW - Benchtop X-ray fluorescence imaging
KW - Gold nanoparticles
KW - Single crystal cadmium telluride detector
KW - X-ray fluorescence
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U2 - 10.1016/j.nima.2021.166198
DO - 10.1016/j.nima.2021.166198
M3 - Article
C2 - 35340930
AN - SCOPUS:85121837802
SN - 0168-9002
VL - 1025
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
M1 - 166198
ER -