Optical, dosimetric, and scintillation properties of pure sapphire crystals

Optical, dosimetric, and scintillation properties of undoped sapphire (Al2O3) single crystals fabricated by different methods of the Czochralski (Cz) and the Bridgman were investigated. In X-ray induced radioluminescence spectra, they showed emission peaks at 240 and 300 nm due to exciton and F+ centers, respectively. Scintillation decay times of F+ center was fast around few ns. As a dosimetric property, from 0.01 to 2 Gy X-ray was exposed to them and they exhibited a thermally stimulated luminescence (TSL) with a good linearity. The glow peaks of them were similar, 150, 250, and 325 °C. In TSL, the Bridgeman sample represented only F+-center emission while the Cz sample showed F at 400 nm and F+ at 300 nm centers emission.