A study of the surface self-diffusion of tungsten induced by ion impact

Ion impact induced surface self-diffusion is studied with a field electron microscope using a new phenomenon, the matter transport of this diffusion caused by capillary forces. Studied is the blunting of the edges of a tungsten crystal by helium ion impact. The order of the coefficient D_i describing this diffusion is determined. D_i is about 10⁶ smaller than estimated by Dranova and Mikailovski. The influence of the ion impact surface roughening is discussed.