The effect of reactor irradiation on the dielectric loss peaks of Nylon and Mylar

The effect of irradiation on the dielectric properties of nylon 66.6 and Mylar was studied. In the case of nylon the dielectric loss peak at 350 K measured with an annular frequency of 10 4 l/s disappeared due to irradiation and the peak at higher temperaturcs shifted to still higher temperatures. In Mylar the α-peak grew in magnitude, indicating an increase in amorphousness, while the β-peak decreased. A rough estimate for the decrease in the magnitude of the effective number of dipoles is presented. The irradiation was carried out up to fast neutron fluence of 3 × 10 17 nvt and gamma dose of 1 × 10 9 rad.