The spatial distribution of self-interstitial atoms around depleted zones in tungsten ion-irradiated at 10 K

Abstract

Abstract The three-dimensional spatial distribution of self-interstial atoms (SIAs) around depleted zones (DZs) in ion-irradiated tungsten was determined by field-ion microscopy (FIM). High-purity, four-pass zone-refined, single crystal tungsten- FIM specimens were irradiated in situ with 30 keV Cr+ or 18 keV Au+ ions along the [741] direction, at 10 K, and examined at this temperature by the pulse-field-evaporation technique. At 10 K the SIAs in tungsten are completely immobile. The distances were measured along the close-packed crystallographic directions—that is, the 〈100〉, 〈110〉 and 〈111〉 directions—between each SIA and the DZs. Distance measurements were also made between each SIA and the irradiated surface of the specimen. The set of distances employed for analysis corresponded to the minimum measured distances; thus, the histograms of the distances presented represent a lower bound (denoted by R min) to the actual propagation distances. For the 30 keV Cr+ ion-irradiated specimen a total of 97 SIAs ...