STP725: Point-Defect Clustering in the Presence of Mobile Helium and Immobile Traps

    Hall, BO
    Physicistsenior scientist, Argonne National Laboratory-WestMaterials Science Division, Westinghouse Research and Development Center, Idaho FallsPittsburgh, IdahoPa.

    Pages: 16    Published: Jan 1981


    Abstract

    A time-dependent model for vacancy and interstitial clustering during irradiation has been modified to include both mobile helium and immobile (solute) traps. The helium interacts only with the vacancies; the solute atoms can trap either type of point defect. With parameters appropriate for nickel-silicon alloys, concentrations of vacancies, interstitials, divacancies, diinterstitials, interstitial helium, vacancy-helium pairs, vacancy-solute pairs, and interstitial-solute pairs were calculated as a function of time for a damage rate ˙n = 10−4 displacements per atom per second: a sink-annihilation probability, p = 10−8, corresponding to a dislocation density of ∼ 108 cm/cm3; T = 773 K; solute concentrations from 10−7 to 10−2 atom fraction; and helium production rates ˙nH = 10−10 and 10−8 atom per atom per second. Various vacancy clustering regimes are identified, and experimental implications of the results are discussed.

    Keywords:

    rate theory, point defects, vacancy clustering, solute trapping, helium trapping, nickel-silicon alloys


    Paper ID: STP28233S

    Committee/Subcommittee: E10.02

    DOI: 10.1520/STP28233S


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