The effect of gamma-ray irradiation on the optical properties of cyclic olefin copolymers

The paper concerns gamma-ray irradiation of cyclic olefin copolymers (COCs). The irradiation occurred in panoramic gamma radiation (from 5.0 to 101.4 kGy at a dose rate of 0.0522 kGy/h) and well irradiation (from 115.6 to 1004.0 kGy at a dose rate of 0.8 kGy/h) facilities, both using a 60 Co source. The effect of irradiation was studied by measuring the refractive indices of the treated materials using dark-field spectroscopy at 532.0, 654.2, 846.4, 1308.2, 1549.1, and 1652.1 nm. Other measurements, such as transmission spectra and changes in chromaticity coordinates, are also mentioned, as are the calculation of absorption coefficients and band gaps.