Phototransferred Thermoluminescence of Dosimetric α-Al₂O₃ Crystals Irradiated by a Pulsed Electron Beam

The thermoluminescence (TL) of deep traps of anion-defective alumina monocrystals irradiated by a high-dose (more than 1 kGy) pulsed electron beam (130 keV) is studied. The deep traps in the studied material are classified according to the TL temperature range. It is demonstrated that the phototransferred thermoluminescence (PTTL) in the temperature range of the main TL peak is induced by optical charge migration from deep traps that are emptied at 400–470 and 470–600°C. An anomalous PTTL enhancement in crystals subjected to stepped annealing in the 350–400°C interval is observed. It is demonstrated that this effect may be caused by competing processes of charge transfer that involve deep traps corresponding to the TL peak at 390°C. The applicability of PTTL in the dosimetry of high-dose (1–50 kGy) pulsed electron beams is established.