Investigation of the effect of gamma rays on optical properties of polymers

The effect of gamma irradiation on the optical properties of cellulose triacetate (C.T.A.) have been investigated. The refractive index measurements were studied on both liquid and solid state samples of the polymer. These samples were exposed to different gamma doses in the range from 0.5 to 32 kGy. The absorbance of the C.T.A. samples in the UV range as well as its colour changes have also been studied in order to develop a sensor for gamma ray dosimetry. Using the transmisison data, both the tristimulus and chromaticity coordinates values were calculated. Ther efractive index for both solid and liquid samples follows the same behaviour with radiation doses. Such behaviour indicates that above 5 kGy the irradiation enhances the isotropic nature of the polymer. (author)