Raman spectroscopy study of β-irradiated silica glass

Natural and synthetic silica glass samples with different OH content have been submitted to β-irradiation at different doses from 10 6 to 5 × 10 9 Gy in a Van de Graaff accelerator. Structural changes under irradiation have been analyzed by Raman spectroscopy. The main findings are: (i) a decrease of the Si–O–Si angular dispersion and the average Si–O–Si angle as a function of dose and (ii) an increase of number of three-membered SiO 4 ring concentration during irradiation. These results show therefore that purely electronic excitation from β-irradiation induces in a-SiO 2 small but significant structural changes of the SiO 4 membered ring statistics (size and dispersion), consistent with a slight densification.