Changes in optical properties of Ce : YAG crystals under annealing and irradiation processing

Changes of optical properties of cerium doped YAG single crystals (0.05, 0. 1, 0.2 at. % Ce, and 0.2 at. % Ce "+" 0.1 at. % Mg) after thermal annealing at 1400 degrees C in air or 1200 degrees C in N-2+H-2 mixture and subseque nt gamma or proton irradiation were investigated. For initial Ce3+ contents <0.05 at. % an increase and for Ce3+ contents >0,05 at. % a decrease of th e final Ce3+ concentration was observed. Appropriate changes in luminescenc e of Ce: YAG crystals were observed as a consequence of dopant concentratio n changes. They were small after gamma-irradiation of Ce: YAG crystals with Ce3+ content >0,05at.% and reached about 100% after gamma-irradiation of c rystals with Ce3+ content <0.05 at. %.