STP529

    A Comparison of the High-Temperature Damage Structures in Accelerator and Reactor Irradiated Molybdenum

    Published: Jan 1973


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    Abstract

    The damage structures produced in high-purity molybdenum by neutrons in a fast reactor and by 2-MeV nitrogen ions in an accelerator have been compared using transmission electron microscopy (TEM). The irradiations have been carried out in the temperature range 450 to 900 C (842 to 1652 F) and doses in the range 10 displacements per atom (dpa) to 200 dpa. Over these ranges the damage structures can be defined in terms of a dislocation component and a void component. Several features of the void structures are found to be independent of the method of damage production, although the dose rate differences affect the temperature range and lower threshold dose for the formation of visible voids. With regard to the dislocation component of the structures, there is a qualitative similarity in distribution of loops and network dislocations between the reactor- and accelerator-irradiated specimens. However, a detailed analysis of the nature of the loops reveals important differences. The loops in reactor-irradiated specimens are predominantly interstitial in nature whereas the loops in accelerator-irradiated specimens containing voids are predominantly vacancy in nature. This result is discussed in detail together with other aspects of the comparative study.

    Keywords:

    radiation effects, radiation damage, electron microscopy, voids, molybdenum, irradiation


    Author Information:

    Eyre, BL
    Group leader, Structural Materials Group, and senior scientific officer, United Kingdom Energy Authority, Harwell, Berks,

    Evans, JH
    Group leader, Structural Materials Group, and senior scientific officer, United Kingdom Energy Authority, Harwell, Berks,


    Paper ID: STP35446S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP35446S


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