Radiation damage of organic composite material for fusion magnet

A Review of Irradiation Effects on Organic-Matrix Insulation

“…Further discussion of three-dimensional reinforced composites and their properties can be found in a paper by Iwasaki et al [1990]. The dielectric properties of 3-dimensional glass weaves may rule out their use for turn-toturn magnet insulation.…”

“…One resin system type that apparently included some aromatic amine hardeners (Formulation 220) retained more than 100% of the initial flexural strength, but the maximum dose was only 1 x 107 Gy. the effects of the B reaction in E glass again, compared to B-free T glass, but note that the composite fabricated with another resin, bismaleimide (Appendix B), but also reinforced with E glass, does not exhibit the same degradation from alpha particles that the E-glass reinforced-epoxy composite does [Nishijima et al, 1991;Okada et al, 1992]. Figure A .7-3 shows that the volume fraction of E-glass-reinforced epoxy does not affect the dose dependence of degradation under combined gamma and neutron irradiation from a reactor at -20 K. It would be of more interest to examine the variation of volume fraction with B-free glass, in case the damage from'alpha particles tended to obscure intrinsic volume fraction effects.…”

“…,.. about 2.8 MeV within a few pm of the boron-containing E-glass Nishijima et al, 1991]; thus, the glass-matrix interface would be considerably weakened. In fact, Egusa et al [1987a; reported calculations that indicated that the energy absorbed in these E-glass reactions added 40% ("Rabbit" irradiation thimble) to 1600% (H2 irradiation thimble) to the nominal dose.…”

“…Reactor irradiation at 20 K was also used by Nishijima et al [1990] to compare the performance of a 3-dimensional glass weave reinforcement with the standard 2-dimensional weave. The resin system was not identified, but was reported to be the same for both types of reinforcement.…”

“…(3) The most common test has been the three-point bend test with a span length/specimen thickness ratio > 5, so that flexure, including tensile and compressive properties, rather than interlaminar shear properties, was primarily measured Becker, 1990;Nishijima et al, 1991].…”