Effect of sequential steady-state and pulsed hydrogen plasma loads on structure of textured tungsten samples

Tungsten samples were exposed to sequential steady-state (particle flux of 1022 m-2 s−1, heat flux of 1.7 MW/m2) and pulsed (surface heat load of 0.45 MJ/m2, pulse duration of 0.25 ms) hydrogen plasmas. Several steps of the steady-state irradiation and pulsed loading were carried out. The samples were studied between the stages of the irradiation with SEM and XRD methods. It has been found that crack network and blisters developed on the surface under irradiation strongly depend on the initial structure of tungsten samples.