Direct observation of the vacancy structure of depleted zones in tungsten ion irradiated at 10 K

Abstract

The structure of depleted zones (DZ’s) created by the in situ irradiation of tungsten specimens, at 10 K, with 30-keV W+, Mo+, or Cr+ ions has been studied by field-ion microscopy. As the mass of the 30-keV ion was decreased the following observations were made: (1) the spatial extent of the DZ’s increased; (2) the vacancy concentration within the DZ’s decreased; (3) the fraction of isolated monovacancies increased; and (4) subcascades formed within the DZ’s.