STP956: Irradiation Effects in KAPTON Polyimide Film from 14-MeV Neutrons and Cobalt-60 Gamma Rays

    Abe, K
    Professor, The Research Institute for Iron, Steel and Other Metals, Tohoku University, Sendai,

    Logan, CM
    Group leader, Lawrence Livermore National Laboratory, Livermore, CA

    Saneyoshi, K
    Research scientist, Tokyo Institute of Technology, Yokohama,

    Clinard, FW
    Senior scientist, Los Alamos National Laboratory, Los Alamos, NM

    Pages: 13    Published: Jan 1987


    Abstract

    Polyimide films are insulating plastic materials that are useful over a wide temperature range and the most radiation resistant of the polymers. In this paper, mechanical property changes of the polyimide film, KAPTON, caused separately by 14-MeV neutrons and by cobalt-60 gamma rays are examined in detail. Miniature tension specimens of 3-mil-thick film were irradiated at Rotating Target Neutron Source-II and at the Cobalt-60 Pool of Lawrence Livermore National Laboratory at room temperature to a maximum neutron fluence of 1.6 × 1022 n/m2 and a maximum gamma dose of 8.6 × 107 Gy, respectively. Neutron fluences greater than 1 × 1021 n/m2 and gamma dose greater than 2.2 × 107 Gy caused a reduction in total elongation of the film. At our highest tested neutron fluence of 1.6 × 1022 n/m2, the elongation dropped to less than one-fifth and the fracture stress dropped to one-third of the unirradiated value. It was found that 14-MeV neutrons were about eight times more effective than cobalt-60 gamma rays in producing mechanical property changes when compared on the basis of absorbed dose. Color changes induced by irradiation were also examined.

    Keywords:

    polyimide, irradiation effects, neutron irradiation, gamma ray irradiation, mechanical properties


    Paper ID: STP25682S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP25682S


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