Features of thermoluminescence in anion-defective alumina single crystals after highdose irradiation

The effect of high-dose irradiation by electron beam with nanosecond duration and by gamma-rays on thermoluminescence (TL) yield of anion-defective dosimetric Al2O3:С crystals is studied. It is shown that in a wide dose range up to 10 kGy no significant changes in the TL curve shape and the temperature position of the main dosimetric peak (T = 460 K) are observed. The TL yield of this peak is in saturation in the high-dose range 5-80 kGy. Then anomalous increase in TL yield is registered at the dose growth up to 800 kGy. With that an intensive band appears in the green spectrum region in the photoluminescence spectrum. The role of aggregate defects forming F2-type centers with the increase of TL yield in Al2O3:С crystals under high-dose irradiation is discussed.