Disorder Induced by Gamma Irradiation in Borosilicate Glasses

Vitrification is the mainstream method for the immobilization of high-level radioactive waste (HLW). As the common matrix of vitrification, the borosilicate glass and its irradiation tolerance have been widely studied. Two kinds of borosilicate glasses were irradiated by gamma rays with absorbed doses from 104 to 107 Gy at ambient temperature. Ultraviolet and visible absorption spectra and Raman spectra were employed to characterize the microstructural changes of borosilicate glass. The Urbach energy of borosilicate glass was obtained from the absorption spectra. The noise intensity of Raman spectra with different absorbed dose were obtained. In addition, the results show that the Urbach energy is positively correlated with the noise of Raman spectra. The disorder of glasses, which was characterized by the noise on Raman spectroscopy and Urbach energy from absorption spectroscopy, increased with the absorbed dose. Finally, compared with the result of Urbach energy, the disorder of the gamma-irradiated glass can be better reflected by the noise intensity of Raman spectra. The study of the gamma radiation effects on vitrification requires more attention than before.