EPR, OSL, TL and spectral studies of porcelain

Porcelain is one of a group of promising building materials for reconstruction of dose from external gamma exposures. The type and lifetime of the recombination centres play an important role in the accuracy of dose assessment, especially if the accident occurred many years before laboratory measurements. The properties of the recombination centres have been investigated by optically stimulated (green) luminescence (OSL), thermoluminescence (TL), phototransfered thermoluminescence (PTTL) and TL glow spectra. The investigations were carried out by TL measurements following green light irradiation of porcelain pre-heated at various temperatures; three photo-transfer peaks were recorded at 110, 170 and 230°C. Among them, the PTTL peaks at 230 and 110°C exhibited pre-dose sensitization. The Al and Ge centres observed by EPR in porcelain were investigated in conjuction with the sensitization of the 110 and 230°C PTTL peaks.