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Showing 1 to 12 of 12 for “"511 keV"”.
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Gamma-ray emission from Galactic millisecond pulsars: Implications for dark matter indirect detection
… Finally, we study the spatial morphology of the 511 keV signal toward the Galactic center using data from INTEGRAL/SPI. We confirm that the 511 keV signal also traces the old stellar population in the Galactic bulge, which is similar to the Fermi GeV excess. Using a 3D smoothing kernel, we find …
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Multi-photon decay mode spectroscopy of positronium
… combines good energy resolutions (5% and 10% at 511 keV for the signals from the eighth dynode and anode of the photomultiplier tube, respectively) with an excellent timing resolution (∼ 300 ps). These energy resolutions were minimised through an optimal selection of the digital signal processing …
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Characterization of water-based liquid scintillator response to gammas and neutrons at varying scintillator-surfactant concentrations
… liquid scintillator to Sodium-22 (²²Na) 511 keV gamma source and Americium-24 Beryllium (AmBe) 2-10 MeV neutron source is explored by taking pulse area spectra data at scintillator-surfactant concentrations of 0.5%, 1.0% and 2.0%. An analysis of light yield reveals an increasing linear …
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Design study of an organ-dedicated positron emission tomography system
… and DOI resolution are measured as 15.66% at 511 keV , 602.98 ps, and 2.33 mm respectively. To optimized the detector geometry, two dual readout cables are further designed to put the readout electronics on the same side of the LYSO. The energy, timing, and DOI resolution of the optimized …
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Design, Calibration, and Evaluation of Depth-of-Interaction-Capable Pet Detector Modules
… single-sided-stopping-power in excess of 95% for 511 keV g's. The noise properties of SSPMs scale with the active area of the detector face, and so the best signal-to-noise ratio is possible with parallel readout of each SSPM photodetector pixel rather than multiplexing signals together. This work …
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Synthesis and characterization of cerium-doped lanthanum halide colloidal nanocrystals
… light yield to absorbed gamma energy) for 662 keV gamma rays, 25 ns short decay time, and a density of 5.3 g/cm3 with 22 mm attenuation length for 511 keV gamma rays. However, the crystals are hygroscopic and hence have to be protected from external environment both during growth and use. …
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Improving the selectivity of the radio-labelling of ion exchange resin tracers for positron emission particle tracking
… in a PET scanner, of the two nearly collinear 511 keV gamma rays resulting from the annihilations of the positrons. For this technique to be effective, the tracer must be representative of the media in the system under study, and labelled with a sufficient activity of radionuclides. Organic ion …
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Some effects on polymers of low-energy implanted positrons
… experiments, the values α = 2.8(±0.2) µg cm−2 keV−n and n = 1.71(±0.05) have been suggested. However, these experiments were performed on several non-detached spin-coated polymers. Therefore, for the first time, positron annihilation experiments are performed on self-supporting nanometric …
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Enhancing PEPT: high fidelity analysis techniques with augmented detection systems
… ns and an energy resolution of 30.51 ± 0.48% at 511 keV was measured for the BGO devices, enabling optimisation of coincidence gates and energy level discriminators respectively. Using a novel 3D positioning stage and a 20.11 ± 0.26 kBq Na-22 calibration source, measurements of system …
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Enhancing PEPT: high fidelity analysis techniques with augmented detection systems
… ns and an energy resolution of 30.51 ± 0.48% at 511 keV was measured for the BGO devices, enabling optimisation of coincidence gates and energy level discriminators respectively. Using a novel 3D positioning stage and a 20.11 ± 0.26 kBq Na-22 calibration source, measurements of system …
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Development of 18F radiochemistry for positron emission particle tracking (PEPT)
… annihilation produces pairs of back-to-back 511 keV gamma photons emitted from the locality of the tracer particle. Pairs of annihilation photons are detected within the field-of-view of a modified positron emission tomography (PET) scanner, and the instantaneous position of the tracer …