Structural defect accumulation in tungsten and tungsten-5wt.%tantalum under incremental proton damage

L. Ipatova, Robert W. Harrison, P.T. Wady, S.M. Shubeita, Dmitry Terentyev, Stephen E. Donnelly, Enrique Jimenez-Melero

    Research outputpeer-review


    We have performed proton irradiation ofWand W-5wt.%Ta materials at 350 C with a step-wise damage level increase up to 0.7 dpa and using two beam energies, namely 40 keV and 3 MeV, in order to probe the accumulation of radiation-induced lattice damage in these materials. Interstitial-type a/2 dislocation loops are formed under irradiation, and their size increases in W-5Ta up to a loop width of 21 ± 4 nmat 0.3 dpa, where loop saturation takes place. In contrast, the loop length in W increases progressively up to 183 ± 50 nm at 0.7 dpa, whereas the loop width remains relatively constant at 29 ± 7nmat >0.3 dpa, giving rise to dislocation strings. The dislocation loops and tangles are observed in both materials examined after a 3 MeV proton irradiation at 350 C. Ta doping delays the evolution of radiation-induced dislocation structures in W, and can consequently impact the hydrogen isotope retention under plasma exposure.
    Original languageEnglish
    Pages (from-to)329-335
    Number of pages7
    JournalJournal of Nuclear Materials
    StatePublished - 1 Apr 2018

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