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Showing 1 to 14 of 14 for “"Transient-grating spectroscopy"”.
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Transient Grating Spectroscopy: Compact System Geometry Developments and Improved Software
Transient grating spectroscopy (TGS) is a rapid, non-destructive technique for measuring the thermal, elastic, and acoustic properties of the top several microns of a reflective surface. It has uses across many areas of materials research. Current TGS systems require complex optics tables taking up …
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Evaluating Fluoride Molten Salt Thermophysical Properties with Transient Grating Spectroscopy
… in non-fluoride salts when measured using Transient Grating Spectroscopy (TGS). This work has shown that convection and radiation are insignificant for most TGS regimes. Therefore, it was hypothesized that TGS measurements of fluorides could finally resolve the discrepancies between theory …
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Breaking the bottleneck in radiation materials science with transient grating spectroscopy
… reactor environment can be accurately predicted. Transient grating spectroscopy (TGS), long used in the materials science field to characterize the properties of thin films, is adapted for use as a method of characterizing radiation-damaged samples. TGS has the ability to simultaneously measure …
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Applications of Transient Grating Spectroscopy to Temperature and Transport Properties Measurements in High-Pressure Environments
Transient Grating Spectroscopy (TGS) is a four-wave mixing technique that involves the first-order Bragg scattering of a probe beam off of a dynamic grating generated by two crossed pump laser beams. The amplitude and temporal behavior of the spatially coherent signal beam reflects the physical and …
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In-situ investigation of the oxidation kinetics of Fe-12Cr-2Si using time-resolved transient grating spectroscopy
… known as dual heterodyne phase collection transient grating spectroscopy is developed for this purpose. This method adapts a traditional spectroscopic technique sensitive to thermal and mechanical properties for real-time use. A formalism is also developed to quantify both elastic and …
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TIME RESOLVED PROBING OF MAGNETO-ELASTIC EXCITATIONS IN MAGNETIC MATERIALS
… Trieste), I developed a setup to perform optical Transient-Grating spectroscopy, and correlative time-resolved optical spectroscopies (time-resolved reflectivity and polarimetry). Via sub-picosecond optical pulses, acoustic and magnetic transients are impulsively generated: their intertwined …
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Photochemical Applications to the Study of Complexity Phospholipid Bilayer Environments
… properties of the bilayer. In addition, transient grating spectroscopy was used to study thermal energy transfer in phospholipid bilayers on a picosecond time scale.Femtosecond transient absorption spectroscopy was used to study the photo-induced spiropyran ring-opening and isomerization …
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Exploring the Effect of Irradiation Time on the Damping of Surface Acoustic Waves
… used to examine material properties, including transient grating spectroscopy (TGS). These properties were used to probe several scales of structure, and TGS has been applied in this way to solve several challenges. This thesis explores the details of the TGS signal itself, and how the property …
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Ultrafast linear and non-linear spectroscopy : from biological light-receptors to artificial light-harvesting systems
… in this work utilize femtosecond time-resolved transient absorption and transient grating as well as picosecond time-resolved fluorescence spectroscopy to investigate the photophysics and photochemistry of biological photoreceptors and address the light-induced excited-state processes in a …
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Multidimensional Spectroscopy With Femtosecond Pulses
… The other method discussed here is a 2nd order transient grating spectroscopy called MUPPETS, a method which enables distinction between homogeneous and heterogeneous sources of nonexponential rates. The specifics of this set up will be detailed, as well as the results of a run performed on …
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Non-destructively detecting spinodal decomposition at a distance towards developing gigahertz ultrasonics for in-vessel inspection
… acoustic wave (SAW) characteristics using transient grating spectroscopy (TGS) to transmission electron microscopy (TEM)-verified evidence of spinodal decomposition and G-phase precipitation. In this thesis, thermal aging is shown to induce SAW peak splitting in spinodally decomposed CASS …
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Optical characterization of complex mechanical and thermal transport properties
… stimulated light scattering (ISS), also known as transient grating spectroscopy, was used to investigate phonon mediated thermal transport in semiconductors and mechanical degrees of freedom linked to structural relaxation in supercooled liquids. In ISS measurements, short optical pulses are …
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Mechanisms and Implementation of Thermo-Optical Annealing in Silica Fiber Sensors for Radiation-Induced Attenuation Mitigation
… We design a white light absorption spectroscopy setup with in-situ irradiation and optical annealing, working at liquid nitrogen temperature and different post-irradiation warm-up rates. For the pure silica core and F-doped cladding fibers studied, the RIA spectrum obtained is …
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Inferring Microstructural Change via Non-Contact Ultrasonic Property Measurements
… for material evaluation via destructive tests. Transient Grating Spectroscopy (TGS) has been proposed as a non-destructive technique that can evaluate material evolution in reactor systems, but its applicability as an inference model has yet to be demonstrated on RPVs or similar systems. In this …