The effect of crystal orientation on the behavior of a polycrystalline tungsten surface under focused Ga+ ion bombardment

The effect of crystal orientation on the behavior of a tungsten surface under a 30 keV focused Ga+ ion beam with different bombardment angles has been investigated by in situ scanning electron microscopy and electron backscatter diffraction. Results indicate that the grains of tungsten with various orientations behave quite differently. Grains with a (0 0 1) direction parallel to the ion beam always maintain a much smoother surface morphology with less mass removal after ion bombardment, indicating a lower sputtering yield. The orientation dependence of surface sputtering of tungsten can be used to guide the fabrication of tungsten-based first wall component in a nuclear fusion reactor.

► We in situ investigated the microstructure evolution during FIB bombardment.
► The irradiation behaviors depended significantly on the crystal orientation.
► Tungsten grain with (0 0 1) crystal orientation showed good irradiation resistance.