Timing calibration is essential for positron emission tomography (PET) system as it enhances timing resolution to improve image quality. Traditionally, positron sources are employed for timing calibration. However, the photons emitted by these sources travel in opposite directions, necessitating that positrons annihilate at multiple locations to collect coincidence data across a greater number of lines of response.
View Article and Find Full Text PDFMonolithic crystal detectors are increasingly being applied in positron emission tomography (PET) devices owing to their excellent depth-of-interaction (DOI) resolution capabilities and high detection efficiency. In this study, we constructed and evaluated a dual-ended readout monolithic crystal detector based on a multiplexing method.We employed two 12 × 12 silicon photomultiplier (SiPM) arrays for readout, and the signals from the 12 × 12 array were merged into 12 X and 12 Y channels using channel multiplexing.
View Article and Find Full Text PDFIonization chamber is considered as the golden standard for the dosemeter. This work fabricated one graphite-walled and two polymethyl methacrylate (PMMA)-walled ionization chambers, tested respectively and compared their characteristic parameters. The performance of graphite-walled chamber was similar to that of the PMMA-walled chamber.
View Article and Find Full Text PDFA 50 × 50 × 10 mm monolithic gadolinium aluminum gallium garnet (GdAlGaO; GAGG):Ce crystal coupled to a 8 × 8 silicon photomultiplier (SiPM) array was developed; it showed very good system uniformity and a high energy resolution of 7.4% at 662 keV. By using a convolutional neural network-based positioning algorithm and a fan-beam calibration method, the detector achieved a position resolution of ∼1.
View Article and Find Full Text PDFWe develop a compact, high signal-to-noise ratio line-detector array Compton scatter imaging system based on YSiO scintillators and silicon photomultipliers. It is shown that the system's response uniformity is better than 98% for low-Z materials after a specific correction. Backscatter images of an "IHEP"-character model, cubes of different materials, and some other applications are presented, to show its potential for use in nondestructive testing.
View Article and Find Full Text PDFThis paper presents a coded aperture method to remotely estimate the radioactivity of a source. The activity is estimated from the detected counts and the estimated source location, which is extracted by factoring the effect of aperture magnification. A 6mm thick tungsten-copper alloy coded aperture mask is used to modulate the incoming gamma-rays.
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