Accumulation features and TL of TLD-500 detectors in a wide temperature range at pulsed and continuous high-dose irradiation

• Using the 580 and 830 K TL peaks allow expand range of the recorded doses to 1 kGy.
• Under pulsed irradiation the upper limit can be expanded to several MGy.
• Ultimate irradiation dose rate of TLD-500 detectors is 1010 Gy/s.
• In the spectrum of the 830 K TL peak an UV emission with hν = 4.1 eV dominates.
• The maximum of the optical depletion spectrum of TL peak at 830 K is around 5.2 eV.

The results of a comparative research of thermoluminescence (TL) of TLD-500 detectors based on anion-defective corundum irradiated with continuous and pulsed X-ray and pulsed electron beams in a range of doses of 0.3 ÷ 107 Gy, dose rates of 0.02–2.6·1011 Gy/s, and in a temperature range of 300–950 K are presented. It is found that, in contrast to continuous irradiation, upon pulsed irradiation with a duration of 10 ns and dose rate of PP ≥ 5·106 Gy/s, the first linear region of dose dependences for TL peaks at 450, 580 and 830 K is, instead of saturation, followed by a second one with a smaller slope at doses near 2, 200 and 103 Gy. Moreover, the slope of the second region increases with growing PP. It was also found that dose dependence for the peak at 830 K in the area of the first linear region at 10–103 Gy remains invariable at PP ≤ 1010 Gy/s. It is shown that the upper limit of doses registered by TLD-500 detectors can be increased to 2·103 and 6·106 Gy for continuous and pulsed irradiation, respectively. New broadband UV luminescence with a maximum hν = 4.1 eV and half width H = 0.85 eV was registered within the TL peak spectrum at 830 K. Besides, the optical depletion spectrum in which a single band with hν = 5.2 eV and H = 1.6 eV is observed was investigated for a trap causing a peak at 830 K.