FIRST-PRINCIPLES CALCULATIONS OF INTRINSIC DEFECTS AND Mg TRANSMUTANTS IN 3C-SiC
Silicon carbide (SiC) possesses many desirable attributes for applications in high-temperature and neutron radiation environments. These attributes include excellent dimensional and thermodynamic stability, low activation, high strength, and high thermal conductivity. Therefore, SiC based materials draw broad attention as structural materials for the first wall (FW) and blanket in fusion power plants. Under the severe high-energy neutron environment of D-T fusion systems, SiC suffers significant transmutation resulting in both gaseous and metallic transmutants. Recent calculations by Sawan, et al.  predict that at a fast neutron dose of ~100 dpa, there will be about 0.5 at% Mg generated in SiC through nuclear transmutation. Other transmutation products, including 0.15 at% Al, 0.2 at% Be and 2.2 at% He, also emerge. Formation and migration energies of point defects in 3C-SiC have been widely investigated using density functional theory (DFT). However, the properties of defects associated with transmutants are currently not well understood. Fundamental understanding of where the transmutation products go and how they affect microstructure evolution of SiC composites will help to predict property evolution and performance of SiC-based materials in fusion reactors.
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- Related Information: Fusion Reactor Materials Semiannual Progress Report for the Period Ending June 20, 2013. DOE-ER-0313/54, 54:189-190
- Peter J. Pappano; Oak Ridge National Laboratory, Oak Ridge, TN, United States(US).
- Research Org:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
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- United States
- Environmental Molecular Sciences Laboratory