THERMALLY STIMULATED LUMINESCENCE ABOVE ROOM-TEMPERATURE OF AMORPHOUS SIO2

The thermoluminescence (TSL) glow peaks and spectral distribution of dry and wet fused quartz and synthetic silica, both as-grown and neutron irradiated, have been studied. A composite peak of intrinsic nature, whose maximum lies between 80°C and 120°C is observed in all the four types of amorphous SiO2. In fused quartz other high temperature (T#62;250°C) glow peaks are observed and are attributed to impurity traps. Neutron irradiation induces the growth of new glow peaks at 150<T<200°C in synthetic silica but it does not modify significantly the glow curves in fused quartz. The spectral distribution of the emitted light has been measured heating the samples up to 100°C. A 2.8 eV band is induced by neutron irradiation in all types of silica. A 3.1 eV band is present in as-grown fused quartz only, its intensity being reduced by the neutron irradiation. These bands are ascribed to intrinsic (structural) and extrinsic (impurity related) recombination centers respectively. © 1990.