Study of deuterium retention in Be-W coatings with distinct roughness profiles

Three batches of pure beryllium (Be), pure tungsten (W) and mixed Be:W (50:50) coatings were deposited by using the thermionic vacuum arc (TVA) technique. Different superficial roughness and morphologies were obtained by adjusting the bias voltages in the substrate holder. The coatings were irradiated afterwards with 15 keV 2H+ ions up to a fluence of 5e17 ion/cm2 with the purpose to investigate the influence of the roughness parameters on the retention of deuterium in Be-W deposits in the absence of other co-deposited impurities. Current densities lower than 0.2 W/cm2 were used to avoid the release of deuterium induced by heating loads. The results of the experiment point to the negligible effect of rugosity on the retention behaviour under energetic ion bombardment.