STP1366: In-situ Electrical Resistivity Measurement of MgO•Al2O3 Coating under Neutron Irradiation

    Nakamichi, M
    Japan Atomic Energy Research Institute, Oarai Research Establishment, Ibaraki-ken,

    Kawamura, H
    Japan Atomic Energy Research Institute, Oarai Research Establishment, Ibaraki-ken,

    Pages: 9    Published: Jan 2000


    Abstract

    Ceramic coatings on the surface of structural materials such as 316SS have been considered for electrical insulators and tritium permeation barriers in fusion reactor designs. MgO•Al2O3 is one of the most promising materials as a coating material from a point of high electrical resistivity and so on. In this report, the electrical resistivity of a MgO•Al2O3 coating on 316SS was investigated under neutron irradiation with the JMTR (Japan Materials Testing Reactor) by in-situ electrical resistivity measurement. The specimen was irradiated at 360°C in a He atmosphere. Radiation Induced Conductivity (RIC) was observed at the beginning of reactor. The electrical resistivity of the coating before neutron irradiation decreased from 1×1011Ω•cm to 2×108Ω•cm with increase reactor power. The electrical resistivity of the coating under neutron irradiation decreased again from 2×108Ω•cm to 5 × 104Ω•cm above 1 × 1019n/cm2 (En> 1 MeV). It did not recover up to unirradiated level. The electrical resistivity of the coating after neutron irradiation was about 2×106Ω•cm. It was clear that Radiation Induced Electrical Degradation (RIED) in the MgO•Al2O3 coating was recognized above a fluence of about 1×1020n/cm2 (En> 1MeV).

    Keywords:

    fusion reactor, neutron irradiation, electrical insulator, MgO•Al, 2, O, 3, electrical resistivity, RIC, RIED, in-situ measurement


    Paper ID: STP12453S

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP12453S


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