Deuterium retention in tungsten-coated reduced activation ferritic/martensitic steel

In order to evaluate tungsten (W) coating performance, thin W film was deposited onto reduced activation ferritic/martensitic steel (F82H) by using rf magnetron sputtering device, then was irradiated at room temperature by 1.7 keV D⁺ ions. After the irradiation, the deuterium retention of the coated sample (W/F82H) was evaluated by thermal desorption spectroscopy (TDS) and compared with those of the F82H and pure W. During TDS measurements, D₂ was desorbed in all materials but HD was only found in significant amount in W/F82H and related to the increase of effective surface area due to the porous film structure. D retention increased with increasing fluence and was accompanied by growth of circular blisters. The size of blisters was limited by the F82H substrate structure. (author)