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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Microstructural dependence on fuel matrix composition in irradiated U-Mo dispersion fuels
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A modern reappraisal of the U-Zr phase diagram
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Impact of composition on the thermophysical properties of (U,Zr)C solid solution Carbide fuels
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Modeling snowflake divertors in MAST-U tokamak using UEDGE code
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SOLPS-ITER modeling of divertor detachment in MAST-U’s super-X double null configuration and comparison to experiment
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First ion temperature measurements in the MAST-U divertor via Retarding Field Energy Analyzer
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Associated Higgs boson production with Z boson in the minimal U(1) extended Standard Model
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Flavored resonant leptogenesis in the U(1) model
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($\mathrm{INVITED}$)Counter-ion effect on the diffusion behavior of $\mathrm{Y}$b, $\mathrm{L}$u, and $\mathrm{N}$d ions in $\mathrm{YAG}$ transparent ceramics
The ability to fabricate additively manufactured laser waveguides with sharp dopant concentration interfaces is limited by diffusion of the dopants at the temperatures required to fully densify the material. Compositional analysis of bilayer samples, where each layer was either undoped YAG or YAG doped with Yb, Lu, or Nd, were fabricated such that all combinations were available for testing. Samples were fabricated at both 1750°C and 1850°C to determine the diffusion behavior of each dopant alone and also in the presence of a second dopant. It was found that the experimental concentration profiles exhibited both intragranular (bulk) and grain boundary contributions, and thus fitting to a complementary error function equation required the use of two diffusion coefficients. Nd always diffused further along grain boundaries than the other dopants, due in part to its small segregation coefficient in YAG. It is shown that the presence of Nd as a counter dopant inhibits intragranular diffusion of other dopants while enhancing their grain boundary diffusion. All the observed trends were attributed to a combination of intragranular lattice strain due to: dopant ions replacing yttrium substitutionally, the relative driving forces for the segregation of dopant ions to grain boundaries, and the ability of one dopant to affect the diffusion of a different dopant in the other direction to maintain charge neutrality.