Synthesis and evaluation of thermoluminescence properties of ZrO:Mg for radiotherapy dosimetry.

This study aimed to investigate the thermoluminescent properties of ZrO:Mg irradiated with a 6 MV X-ray beam and its potential application in radiotherapy dosimetry. ZrO powder was synthesized using the sol-gel method and Mg was used as a dopant. Irradiations were performed with ZrO:Mg chips located at the center of a 10 × 10 cm radiation field at a source surface distance of 100 cm, below a stack of solid water slabs, at the depth of maximum absorbed dose. The investigated characteristics of the material included linearity with radiation dose, reproducibility, accuracy, sensitivity and fading. Regarding the intrinsic difference of the samples, the glow curves of the investigated ZrO:Mg chips exposed to 1 Gy of 6 MV X-rays exhibited three or four peaks. The ZrO:Mg samples showed a 47% fading at 24 h after irradiation, and the reproducibility of the thermoluminescence reading of ZrO:Mg for equal irradiation conditions was ± 21%. The thermoluminescence response of the investigated ZrO:Mg samples to various absorbed doses from 0.5 to 2.5 Gy showed a gentle increase of the thermoluminescence intensity with increasing absorbed dose. The obtained results show that ZrO:Mg is not an appropriate candidate for X-ray photons in radiotherapy, due to low thermoluminescence peak temperature, low reproducibility, low sensitivity to various absorbed doses and significant fading.