Deuterium and helium retention in W and W-Ta coatings irradiated with energetic ion beams

Different studies reveal the behaviour of Ta alloying to decrease deuterium retention in tungsten bulk materials aiming to be used for nuclear fusion applications. In this work, W and W-5 %Ta coatings were produced via magnetron sputtering techniques. The elemental composition of the samples and the spread of Ta in the W lattice was confirmed by GDOES, PIXE and by μ-PIXE, respectively. Sets of W and W-Ta coatings were simultaneously irradiated with a single 2H2+ or with sequential 4He+/2H2+ ion beam implantations using incident energies of 30 keV and ion fluences of 5 × 1017 ion/cm2. The irradiated samples were analysed by NRA/RBS and by ToF-ERDA to quantify the retained deuterium and helium amounts. The results reveal significantly lower contents of both isotopes in W-Ta.