A linear array silicon pixel detector has been developed to perform digital radiology with synchrotron radiation: in this communication we present the first results obtained using a three layer prototype at the Elettra Synchrotron Radiation Facility (Trieste, Italy). High efficiency (about 85% at 20 keV) is achieved by means of a Si strip detector irradiated in an `edge-on' geometry: the pixel dimensions are 200×300 μm2. To obtain a sensitive area of about 50xl mm2 a stack of three layers has been assembled. Images are obtained by means of scanning techniques and their spatial resolution is determined by the scanning step. Detectors are read-out by dedicated, low noise VLSI CMOS chips in single photon counting mode. The distance between each detector layer has been measured to be 115±10 μm and the layers are parallel within a maximum tilt angle of 0.08°. Cross-talk effects were found to be always smaller than 2% of the counts of the neighboring layers. The MTF in the scan direction has been evaluated. The acquisition time needed to acquire an image of a mammographic test object is about 6 minutes. The mean glandular dose is about 30% of the dose delivered at the conventional mammographic unit for the same test object while the detail visibility is comparable. These preliminary results indicate that a large area linear array silicon pixel detector can be developed: using this detector and a monochromatic synchrotron radiation beam the delivered mean glandular dose is significantly reduced when compared to conventional mammographic examinations.
Arfelli, F., Bonvicini, V., Bravin, A., Cantatore, G., Castelli, E., Palma, L., et al. (1999). Preliminary results with a three-layer linear array silicon pixel detector. In Proceedings of the 1999 Medical Imaging - Physics of Medical Imaging (pp.817-825). Society of Photo-Optical Instrumentation Engineers [10.1117/12.349562].
Preliminary results with a three-layer linear array silicon pixel detector
Bravin A;
1999
Abstract
A linear array silicon pixel detector has been developed to perform digital radiology with synchrotron radiation: in this communication we present the first results obtained using a three layer prototype at the Elettra Synchrotron Radiation Facility (Trieste, Italy). High efficiency (about 85% at 20 keV) is achieved by means of a Si strip detector irradiated in an `edge-on' geometry: the pixel dimensions are 200×300 μm2. To obtain a sensitive area of about 50xl mm2 a stack of three layers has been assembled. Images are obtained by means of scanning techniques and their spatial resolution is determined by the scanning step. Detectors are read-out by dedicated, low noise VLSI CMOS chips in single photon counting mode. The distance between each detector layer has been measured to be 115±10 μm and the layers are parallel within a maximum tilt angle of 0.08°. Cross-talk effects were found to be always smaller than 2% of the counts of the neighboring layers. The MTF in the scan direction has been evaluated. The acquisition time needed to acquire an image of a mammographic test object is about 6 minutes. The mean glandular dose is about 30% of the dose delivered at the conventional mammographic unit for the same test object while the detail visibility is comparable. These preliminary results indicate that a large area linear array silicon pixel detector can be developed: using this detector and a monochromatic synchrotron radiation beam the delivered mean glandular dose is significantly reduced when compared to conventional mammographic examinations.
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