Pre-implantation and pre-annealing effects on deuterium retention in tungsten

Ion-driven deuterium retention in polycrystalline tungsten has been studied by thermodesorption spectroscopy as a function of the pre-implantation and pre-annealing treatments. Two kinds of tungsten samples were implanted by deuterium ions: (i) as-received W and (ii) re-crystallized W. Higher deuterium retention has been found for as-received W compared to re-crystallized. Pre-implantation by deuterium ions with intermediate TDS increases the deuterium retention. An increase of the deuterium retention with temperature at relatively high fluences was observed. The possible mechanisms of this behavior are discussed.