Deuterium transport in ITER-grade tungsten

Abstract The transport behavior of hydrogen isotopes in ITER grade tungsten (IG-W) and commercial rolled polycrystalline tungsten (CR-W) was investigated using deuterium gas. Analyses using field-emission scanning electron microscopy revealed that both IG-W and CR-W had a polycrystalline structure, but their surface grain structures were apparently different. The permeability and diffusivity of deuterium in IG-W and CR-W were obtained using a time-dependent gas-phase technique in the temperature range of 650–850°C, being observed to be affected by surface morphology and grain boundaries. Our results in this study were also compared with previous results for polycrystalline W reported by other authors.