Molecular Dynamics Simulations of Deuterium Trapping and Re-emission in Tungsten Carbide

Tungsten carbide is exposed to deuterium plasmas in fusion reactors. In this context, studying of the interaction between deuterium and impurities originating from the plasma and tungsten carbide is of scientific interest. Molecular dynamics simulations of cumulative deuterium cobombardment with C, W, He, Ne, or Ar impurities on crystalline tungsten carbide were performed with ion energies of 100−300 eV. The temperature was 600 K, and the ion flux was 3.38 × 10 28 m −2 s −1 . During the bombardment, the sample surface changed from crystalline to amorphous. Deuterium was trapped in the sample, followed by D 2 accumulation into bubbles, which lead in some cases to a “blistering”-like effect. Annealing of the samples after 5000 impacts for 1 ns showed re-emission of D 2 molecules for the 100 eV bombarded samples and no re-emission for the 300 eV bombarded samples.