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Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Theses and Dissertations
Thermal Ionization Mass Spectrometry (TIMS) is an invaluable tool in nuclear forensics as it enables isotopic assays of actinides to be measured, permitting analysis to include special nuclear material isotopic assays, nuclear reactor monitoring, and treaty verification. In one method of measurement for the TIMS system, samples are deposited in solution form on high-purity rhenium filaments. The filaments are heated to evaporate the solvent, and then further heated to cause sample ionization, permitting the sample to be transmitted through a magnetic field which separates ions based on mass to charge ratio into detectors for counting. Heavier ions will be deflected …
Using Principal Component Analysis To Improve Fallout Characterization, Derek W. Haws
Using Principal Component Analysis To Improve Fallout Characterization, Derek W. Haws
Theses and Dissertations
Previous research conducted at Lawrence Livermore National Laboratory (LLNL) and the Air Force Institute of Technology (AFIT) has shown a correlation between actinide location and elemental composition in fallout from historic weapons testing. Fifty spherical fallout samples were collected from near ground zero of a surface burst weapons test. The samples were mounted in an aluminum puck then ground and polished to a hemisphere exposing the central plane. Physical morphologies of the samples ranged from clear to opaque with inclusions, voids, and/or uniform characteristics. Spectroscopy data were collected using optical microscopes and scanning electron microscopy (SEM), with radioactivity recorded through …
Vibration Analysis Of Commercial Thermal Barrier Coatings, Lindell E. Pearson
Vibration Analysis Of Commercial Thermal Barrier Coatings, Lindell E. Pearson
Theses and Dissertations
Thermal barrier coatings (TBCs) are currently used in turbine engine components to protect substrate material from being exposed to high temperatures and corrosion. These coatings also have the potential to reduce stress in critical engine parts which could increase the life cycle of these parts. The fact that these coatings are already qualified for use in turbine engines makes it worth investigating their damping properties. The problem with TBCs is that they are difficult to characterize as they display nonlinear properties. This research utilizes an experimental and finite element procedure to characterize these coatings. A scanning electron microscope (SEM) was …