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LiF crystal doped with magnesium (Mg), copper (Cu) and phosphorous (P) was grown in the form of multicrystalline sheet using Edge-defined film-fed growth (EFG) technique for dosimetry application. These crystals were grown in argon gas atmosphere using graphite crucible and stainless steel die. Dosimetry peak was observed at 210 °C for as-grown crystal. As reported earlier LiF:Mg, Cu, P is a highly sensitive material but losses its sensitivity if annealed at temperature above 240 °C. In this paper, the effect of annealing temperature on thermoluminescence glow-curve structure, maximum peak temperature, peak height and integrated area of the glow peak of EFG grown samples was investigated in detail. Annealing temperature range from 220 °C to 500 °C was considered for the study. Experimental results of the obtained glow curve show that with increase in annealing temperature, glow peak shift towards higher temperature region with substantial increase in TL intensity. Annealing at 500 °C for 10 min gave maximum TL intensity with main dosimetry peak positioned at 233 °C. Change in the defect structure with different pre-annealing temperature was analysed using trapping parameters. [ABSTRACT FROM AUTHOR]

• TL properties of perovskite NaMgF 3 :Tb synthesized using solid state reaction method and melting method have been investigated. • TL properties of NaMgF 3 :Tb irradiated with gamma rays is reported firstly. • Single TL glow curve structure, linear TL response for 10 Gy – 500 Gy, low TL fading characteristics has been observed for the sample prepared using melting method. • NaMgF 3 :Tb synthesized using melting method is a potential TL dosimeter for the detection of gamma rays. NaMgF 3 is a recognized sensitive thermoluminescence (TL) dosimeter but it shows fading at room temperature which limits its use as a radiation dosimeter. It is important to improve this parameter of NaMgF 3 for its potential application in the field of radiation dosimetry. Thus, the current work focuses on enhancing the dosimetric properties of NaMgF 3 exclusively the TL fading characteristics. In the present study, Tb doped NaMgF 3 has been synthesized by two different methods i.e. solid state reaction method (SSR) and melting method (MT). A comparative and detailed TL studies have been carried out after irradiation with gamma rays which has not been reported so far. Detailed analysis of TL and Photoluminescence (PL) properties reveal that NaMgF 3 :Tb prepared via MT shows good luminescence properties in comparison to SSR and previously reported results. Thus, Tb doped NaMgF 3 synthesized by melting method can be a potential dosimeter for the detection of gamma rays. [ABSTRACT FROM AUTHOR]

MgO is drawing considerable attention owing mainly due to its tissue equivalency (Z eff = 10.8) and excellent luminescence response. In this work, we report the synthesis and investigation of a highly sensitive MgO: Li, Sm phosphor in nanocrystalline form for TL dosimetry application. The structural and morphological study has been done using X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). TL intensity of gamma irradiated MgO nanophosphor increases with doping of Li and further improves by co-doping with Sm. The MgO: Li, Sm nanophosphor exhibit TL glow curve structure having isolated single peak at 169 °C and linearity in the low dose (13 mGy-5 Gy) as well as high dose range (10–1000 Gy). The TL structure and peak position remains stable at all doses. The phosphor shows excellent stability (low fading rate) and repeatability. TL intensity of MgO: Li, Sm is 12 times higher than that of commercially available LiF: Mg, Ti (TLD 100) and almost equivalent to LiF: Mg, Cu, P (TLD-700 H). This may be attributed to the formation of greater number of density of traps and suitable trapping levels with optimum dopant selection in MgO nanophosphor. The incorporation of the Sm3+ has improved the TL intensity manifold with appearance of desired isolated single peak. The photoluminescence (PL) spectra confirm the Sm3+ emission at 566, 603, 651 and 708 nm with an excitation wavelength of 315 nm. Further the role of dopants has been discussed on the basis of charge transfer mechanism and corelated with associated kinetic parameters for better understanding of TL process. The newly explored MgO: Li, Sm nanophosphor has shown attractive TL dosimetry properties owing to its high sensitivity, stable glow curve structure, dose linearity, low fading and repeatability which meet all the requirement to establish this as a next generation TL phosphor for medical and personal dosimetry application. [Display omitted] • Synthesis of MgO: Li, Sm phosphor in nanocrystalline form using solution combustion method. • TL sensitivity of MgO: Li, Sm nanophosphor is ∼12 times higher than TLD- 100 and close to TLD-700 H. • The phosphor show stable glow curve structure and good linearity. • The Sm3+ has improved the TL intensity manifold with appearance of isolated single TL peak. [ABSTRACT FROM AUTHOR]