Impact of glass density on the green emission and NBOHC formation in silica glass: A combined high pressure and 2.5Â MeV electron irradiation

Macroscopic Suprasil F300 type silica glasses densified under high pressure and high temperature were irradiated with 2.5 MeV electrons. This paper focuses on the point defects generation in those densified silica glasses. We demonstrated that the unattributed 540 nm emission band was clearly enhanced when the irradiated glasses exhibit a higher density either initially generated by high pressure cycle or by irradiation at high dose (> 3 GGy). The spectral shape of the emission band related to Non Bridging Oxygen Hole Center (NBOHC) is also modified with a broader FWHM due to an additional contribution near 610 nm indicating a larger distribution of NBOHC species in these densified glasses.