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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"incident photons"”.
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REGULARIZATION PARAMETER SELECTION METHODS FOR ILL POSED POISSON IMAGING PROBLEMS
… image intensity is measured by the counting of incident photons emitted by the object of interest, the data-noise is accurately modeled by a Poisson distribution, which motivates the use of Poisson maximum likelihood estimation. When the underlying model equation is ill-posed, regularization …
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REGULARIZATION PARAMETER SELECTION METHODS FOR ILL POSED POISSON IMAGING PROBLEMS
… image intensity is measured by the counting of incident photons emitted by the object of interest, the data-noise is accurately modeled by a Poisson distribution, which motivates the use of Poisson maximum likelihood estimation. When the underlying model equation is ill-posed, regularization …
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Development and validation of a theoretical model for optimizing signal-to-noise ratio in x-ray fluorescence imaging
… of improving system sensitivity is by adjusting incident beam spectra shape. The predominant component of scattering noise originates from incident photons whose energy is several keV higher than fluorescence line. After Compton scattering with sample, those photons will lose energy to have the …
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A GEANT4 simulation of the recoil proton stopping acceptance in the near-threshold γ p [right arrow] [pi]⁰p reaction on a scintillator target
… was generated to be uniform in cos OCM and OcM- Incident photons with energy uniformly distributed in the range of 150MeV to 250MeV were used. The simulation focused on the effects of the size of the incident photon beam. In additions, the hardening efficiency of the bremsstrahlung photon beam …
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The design and performance of an x-ray emission spectrometer using the polarized Kalpha spectra of chlorine and potassium
… of a sample by synchrotron radiation. The incident photons are intense, monoenergetic and linearly polarized along the plane of the storage-ring orbit. The emission spectrometer records the entire K-alpha spectrum by dispersing the emitted radiation with a curved Si (111) crystal and …
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Differential cross sections for the reaction He4(gamma, p)H3 from 55 to 165 MeV
… been measured for the reaction He4 (y,p)H3 for incident photons of 55 to 165 MeV. Outgoing protons and tritons from a low temperature He target were detected in coincidence at three angular settings in the 1aboratqry: (8p ' 8T) = (59.5, 106°), (88.5°, 75°), and (118°, 47.5°). The triton …
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Spectral Computed Tomography at High Photon Fluxes
… to resolve the spectral composition of the incident photons in X-ray imaging, provided that the detector is operated in the absence of pulse pile-up and sensor polarisation. The purpose of this study is to examine the imaging properties of Medipix2 MXR detectors under high photon fluxes, …
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Control of Light-Matter Interactions via Nanostructured Photonic Materials
… to induce a resonant behavior with incident electromagnetic field of optical wavelengths. This allows field enhancement in highly localized areas to strengthen exotic light-matter interactions that would otherwise be too weak to measure or for practical use. In this regard, the work …
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Two-dimensional photonic crystals as selective emitters for thermophotovoltaic power conversion applications
… (PV) diode. The emitter is heated and radiates photons of various energies. The PV diode captures the incident photons whose energy is equal to or greater than the band-gap energy of the PV diode. Ideally, all captured photons are converted into electricity. This thesis develops the fabrication …
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Computational Dead Time Correction in Fluorescence Lifetime Imaging Microscopy (FLIM)
… when the detection system cannot record new photons. The effect of dead time on the measured fluorescence intensity and lifetime is highly dependent on the photon rate (the number of incident photons per laser period). Dead time causes photon counts to be underestimated, especially at high …
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Fabrication and testing of an infrared spectral control component for thermophotovoltaic power conversion applications
… source emits a radiative spectrum, which is incident upon a photovoltaic (PV) diode. The PV diode then converts some of the incident photons to electricity. The photons which are converted to electricity have energies greater than the electronic bandgap of the material from which the PV diode …
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Development of the Visible Light Photon Counter for Applications in Quantum Information Science
… coefficient of Si is high and most of the incident photons are absorbed within the top contact of the device, whereas, in the infrared, Si is practically transparent. A number of applications in quantum information science would benefit from use of the VLPC if the QE was improved in the …
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Influence of Solvent Additives on Stability, Performance and Morphology of Conjugated Polymer/Fullerene Based Organic Bulk Heterojunction Solar Cells
… of light is absorbed in the donor material. The incident photons are converted to excitons which get separated into holes and electrons at a donor/acceptor interface. Donor/acceptor regions can be optimized using techniques such as thermal annealing and solvent additives. Diiodooctane (DIO) …
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Photoproduction and Radiative Decay of ηt Meson in CLAS at JLAB
… National Accelerator Facility using tagged incident photons in the center-of-mass energy range 1.96 GeV - 2.72 GeV. The measurements are performed on a liquid hydrogen target in the reaction <em>γp → pη</em><em>/</em>(<em>η</em><em>/ </em><em>→ π</em>+<em>π</em><em>−</em><em>γ</em>). The …
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Eta photoproduction study with the upgraded Glasgow tagger at MAMI
… selection of this S_11 intermediate state, for incident photons in the energy range 700 to 1400MeV. The S_11(1535) is a well-established resonance, but its composition is a contentious topic, requiring further experimental data to distinguish between competing theories. The MAMI electron …
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A Systems Framework for Multi-Messenger Astronomy
… regards the use of multimodal information — incident photons, gravitational waves, neutrinos, and cosmic rays — to form astrophysical inferences. Since each messenger interacts uniquely with the dynamics of the phenomena in question, drawing information from multiple messengers poses a more …
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Long range x-ray imaging utilizing coded aperture techniques and dynamic reconstruction
… and environmental sources, as well as to prevent incident photons from directly reaching the detector from the x-ray tube. Measurements of a Co-60 point source and Co-57 area source with high activity generated high contrast images for which the shapes of the sources were clearly resolved. …
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High efficiency luminescent solar concentrator with interconnected gallium indium phosphide micro solar cells
… losses due to the mismatch between the energy of incident photons and the bandgap of semiconductors. GaInP is close to ideal in terms of bandgap in tandem with silicon. Due to its high cost of fabrication, the area of GaInP must be much smaller than Si in an economically viable GaInP//Si …
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Photon-Number Resolving by Superconductive Devices
… require to be able to resolve the number of photons in a light pulse. Presently state of the art indicates that classical semiconductor light detectors (i.e. avalanche photodiode or single photon avalanche diode) are not able to discriminate the number of photon arriving at the same time. In …
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Interferometry with higher-dimensional gauge-symmetric optical multiports
… redistribute the energy carried by incident photons, and the phase delays that freely propagating photons experience between pairs of these scattering centers. When an interferometer is modeled as a generic graph, these aspects may be represented by the vertices and edges, …
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