Effect of Grain Orientation on Surface Damage of Niobium Doped Tungsten with Helium Implantation

Abstract

Niobium doped tungsten was irradiated by helium ion implantation, and the effect of grain orientation on surface damage induced by helium sputtering was studied by X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and electron backscattered diffraction. Many cavities or pores caused by helium sputtering were observed on the surface of the samples, and the surface damage of tungsten by helium irradiation was aggravated by 1.0 x 10(18) Nb/cm(2) doping. It was found that the surface damage of different crystal orientations was distinct under same helium implantation condition. The surface damage of grains with (1 1 0) orientation was worse than that of grains with (1 1 1) and (1 0 0) orientation. The result suggested that the surface damage induced by helium sputtering was closely related to helium implantation fluence and grain orientation.