Characterization of advanced cyanate ester/epoxy insulation systems before and after reactor irradiation

Insulation systems for fusion magnets have to operate in a harsh environment, especially also under intense radiation. Over the past years, cyanate ester (CE) resins have been playing an increasingly important rolebecauseof their enhanced temperatureandradiation resistancecompared toconventional epoxy resins. Blending CEwith epoxy resins offers the possibility tomanufacture radiation resistant insulations at a low price compared to pure CE materials. Therefore, it is of special interest to study the influence of the CE content and of the epoxy resin on the mechanical properties to find materials, which are suitable and economically reasonable for the specific demands of such magnets. In this study R-glass fiber/Kapton reinforced cyanate ester/epoxy blends with different CE content were investigated. Eachmaterial was exposed to conditions matching those expected for the ITER TF coil insulation as closely as possible. In order to characterize the mechanical properties, short-beam shear and static tensile tests were carried out at 77K prior to and after irradiation to fast neutron fluences of up to 5×1022 m−2 (E>0.1MeV), in the TRIGA reactor (Vienna) at ambient temperature (340K). In addition,