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Showing 1 to 20 of 54 for “"Rayleigh scattering"”.
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Non-Rayleigh scattering by a randomly oriented elongated scatterer
… false alarm (PFA) are shown to be strongly non-Rayleigh and a strong function of shape of scatterer. The tails are shown to increase above that associated with a Rayleigh distribution with increasing degree of elongation (aspect ratio) of the scatterer and when roughness effects are introduced. …
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Hyper-Rayleigh scattering measurements of hyperpolarizabilities for tetrahedral molecules
… methane, and methane have been measured by hyper-Rayleigh scattering in gas and liquid phases. The gas-phase results for the coefficient beta xyz (atomic units) are 11.0 +/- 0.9 (CC14), 5.4 +/- 0.4 (CF4), 7.0 +/- 0.6 (CD4), 7.1 +/- 0.7 (CH4). Ab initio calculations are consistent with the measured …
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Non-Rayleigh scattering by a randomly oriented elongated scatterer
… false alarm (PFA) are shown to be strongly non-Rayleigh and a strong function of shape of scatterer. The tails are shown to increase above that associated with a Rayleigh distribution with increasing degree of elongation (aspect ratio) of the scatterer and when roughness effects are introduced. …
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Unbiased Filtered Rayleigh Scattering Measurement Model for Aerodynamic Flows
The filtered Rayleigh scattering (FRS) optical diagnostic has become an attractive technique for advanced aerodynamic measurements. The appeal of FRS is that it can simultaneously quantify density, temperature, and vector velocity. Additionally, it is entirely non-intrusive to the flow since the …
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Filtered Rayleigh Scattering with an Application to Force Component Decomposition
Filtered Rayleigh scattering (FRS) is a laser-based measurement technique that makes use of the scattering of light off particles that are much smaller than the wavelength of light that hits them (i.e., Rayleigh scattering of air molecules). The scattered laser light is altered after encountering …
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Multi-Property Internal Flow Field Quantification using Molecular Filtered Rayleigh Scattering
… non-intrusive measurements using filtered Rayleigh scattering (FRS) are presented and analyzed for the multi-property quantification of internal flow fields. Validation is challenging in applying computational fluid dynamics (CFD) solutions to real-world scenarios, necessitating benchmark …
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Ultraviolet (UV) Laser Implementation, Signal Model, and Measurement Sensitivities in Filtered Rayleigh Scattering for Aerodynamic Flows
Filtered Rayleigh scattering (FRS) is a non-intrusive, optical measurement technique that can currently provide time-averaged, simultaneous planar measurements of three-component velocity, static temperature, and static density of aerodynamic flows. Development of the FRS technique has typically …
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Rayleigh scattering of the Cosmic Microwave Background: Towards a first detection with the next generation of surveys.
… to observe beyond the CMB primary modes. Rayleigh scattering of the CMB is one source of additional cosmological information. It is caused by the additional scattering of CMB photons by neutral species formed during recombination and exhibits a strong and unique frequency scaling (∝ ν4). …
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A Study of the Effects of Polarization, Electron Binding, and Rayleigh Scattering in Monte Carlo Gamma-Ray Transport Calculations
Made available in DSpace on 2014-12-09T19:52:26Z (GMT). No. of bitstreams: 1 6901475.pdf: 8658294 bytes, checksum: eac285bf4583ef6af61a9dbaaaef12d8 (MD5) Previous issue date: 1968
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Fuel-vortex interactions for enhanced mixing in supersonic flow
… flux ratios of 1.0 and 2.0. Planar-laser Rayleigh scattering and conventional probing techniques including species composition sampling were employed to interrogate the flow field at several downstream locations. Results show that with increasing jet momentum, the aero-ramp exhibited a …
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Characterization of Scintillation Light in Large Liquid Argon Detectors and the Implications for Proton Decay Searches
… of study with open questions about the impact of scattering and absorption in such a large detector. Here, we combine ProtoDUNE-SP cosmic-ray data with its large photon detector coverage and large drift volume to measure the Rayleigh scattering length of pure liquid argon, nitrogen contaminated …
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Low threshold random lasing from phase separated optical fibers.
… presented. The core exhibits greatly enhanced Rayleigh scattering, therefore requiring a significantly reduced length of scattering fiber (4 m) for lasing. The enhanced Rayleigh scattering was verified through measurements and a new figure of merit called effective power reflectivity was also …
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Manipulating Bose-Einstein condensates with laser light
… Spontaneous and stimulated off-resonant light scatterings were studied experimentally. Stimulated, two-photon Bragg scattering was used for spectroscopic measurement of the mean-field energy and of the intrinsic momentum uncertainty of the condensate. The high momentum and energy resolution of …
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Microscopic Theory of Linear Response in Amorphous Materials
… of phonon transport in disordered materials. The Rayleigh scattering may be enhanced by a logarithmic factor in an intermediate range of wavenumber. I present a tensorial replica field-theoretic derivation based on heterogeneous or fluctuating elasticity, which suggests that long-range spatial …
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Suppression of disorder-induced scattering in optomechanical systems
… may be frozen-in or even dynamically induced. Rayleigh scattering is observed in nearly all wave-guiding technologies today and can lead to both irreversible radiative losses as well as undesirable intermodal coupling. The mitigation of disorder-induced scattering is extremely challenging for …
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Raindrop size distribution
… relationship). Also introduce the theory of scattering by such hydrometers as rain, snow, hail and fog. There are three techniques to determine the scattering parameters are Rayleigh Scattering, Mie Scattering and T-Matrix method.
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Studying the atmosphere of HD 189733 b using the Rossiter-McLaughlin effect
… This makes them insensitive to the strong Rayleigh scattering slope of HD 189733 b that is due to possible atmospheric aerosols. The Rossiter-McLaughlin (RM) effect provides a way to probe broadband spectral features because its amplitude varies as a function of wavelength according to the …
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High-Definition Raman-based Distributed Temperature Sensing
… research. DTS uses the principle of backscattering by three different spectral components, e.g., Rayleigh scattering, Brillouin scattering, and Raman scattering. Although there have been various improvements to DTS, its slow response time and poor spatial resolution have been hard to …
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Raindrop Size Distribution Retrieval And Evaluation Using An S-band Radar Profiler
… distribution model is introduced, which uses Rayleigh scattering portion of the Doppler velocity spectrum to estimate the raindrop size distribution. This theoretical scattering model was validated by simulating atmospheric profiles of precipitation Doppler spectra and three moments …
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Velocity, temperature, and electric field measurements on a plasma-assisted hydrogen diffusion flame
… species measurements of the flame, by means of Rayleigh or Raman scattering techniques, in different regimes demonstrated a change in the fuel mixing structure and location of the reaction zone due to the position and intensity of the plasma-induced toroidal vortex. Finally, optical electric …
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