Determination of optimal material as TLD device for radiation dosimetry application

A comprehensive study of the structural, morphological, thermoluminescence, and dosimetric characterization of three materials was conducted to determine the optimal material as a TLD device for dosimetry applications. The materials considered were silica glass beads, ZnO, and MgO. The silica glass bead was manually arranged with sandpaper to have dimensions similar to a TLD chip (LiF) with a diameter of 4.5 mm and a thickness of 1 mm. The samples were irradiated by a beta source, 90Sr/Y, with an absorbed dose of 10 Gy, and then the TL/OSL system reader Lexsyg Smart was used to observe TL signals. It never exhibited any response to the radiation, even with an increase in the absorbed dose up to 10 Gy. This can be explained as this material doesn't have sensitivity to radiation. 0.2M of zinc sulfate (ZnSO4.7(H2O) was dissolved in 50 mL of deionized water to prepare zinc oxide material via the chemical spray deposition technique. Structural measurements were conducted via the X-ray diffraction system. The results revealed that the pattern can be indexed as the hexagonal phase, and the value of the diffraction peak of 2θ was found at 34.467° with the attribute (002) as a preferred orientation for crystallography. Morphology measurements were carried out using a scanning electron microscopy system, and the results revealed that the surface includes nanoparticles with sizes ranging from 170 to 300 nm. Band gap estimation was calculated by UV spectrophotometer analysis; the results revealed that the band gap of the ZnO nanomaterial is 3.1 eV. A TLD reader system (Harshaw 3500) was used to measure the thermoluminescence properties of ZnO after being exposed to an absorbed dose of up to 10 Gy, and the results showed a low TL intensity glow curve since ZnO has some unwanted impurities inside the crystal. 0.2 M of magnesium chloride was dissolved in 50 mL of deionized water to prepare the MgO material. XRD measurements revealed that the MgO pattern verified a pure cubic structure without undesirable secondary phases or contamination. Morphology measurements showed that the MgO nanomaterial's surface has spherical as well as irregular forms in various dimensions ranging from 50 to 100 nm. The band gap energy was calculated by UV-Vis measurements, and it was found to be 3.7 eV. TL measurements and the dosimetric characterization of MgO showed a good response to the absorbed doses when the sample was irradiated up to 200 Gy. The intensity of the TL-glow curve increased with the rise of the absorbed dose and exhibited good linearity. The results indicated that MgO nanomaterial is an optimal material as a TLD device for radiation dosimetry applications.