First-Principles Study of Properties and Helium Behavior of Tungsten/Beryllium Interface Structure

A computational study of the thermodynamic and elastic properties of the tungsten-berylliuminterface structure and the behavior of a helium-vacancy pair near the tungsten/beryllium interface is carried out by first-principles calculations. Briefly, the following properties were calculated: (1) electronic properties of the tungsten/beryllium interface structure and (2) thermodynamic functions, Gibbs free energy, entropy, and enthalpy and anisotropies and isotropic (poly-crystalline) elastic moduli (bulk, torsion, Young’s moduli) of the tungsten/beryllium interface structure containing helium interstitial atoms or helium-vacancy pairs. The computational study was to provide a critical appraisal of the effect of helium interstitial atoms on the properties of the tungsten/beryllium interface structure. Calculated interface properties could be incorporated in an antiradiation damaging feature evaluation system to develop and test tungsten-based composites as plasma-facing materials.