Hydrogen interaction with Al2O3-coated tungsten under plasma irradiation

The effect of amorphous films of Al2O3 on deuterium trapping in polycrystalline tungsten under plasma irradiation (150 eV/D) and high fluence (up to 4 × 1024 D/m2) was studied by the methods of nuclear reaction product spectroscopy and thermal desorption spectroscopy. It was determined that the hydrogen permeation blocking properties of aluminium oxide lead to a great increase in deuterium trapped in tungsten. With the complete erosion of the film, this effect continues but with a lower amplitude. Extrapolation of this property to beryllium oxide implies that the presence of beryllium oxide on the surface of the tungsten tiles of the ITER leads to a considerable increase in the tritium inventories accumulated in them.