Search

Thermoluminescence dosimeters (TLDs) are widely used in radiation dosimetry due to their excellent properties, such as high sensitivity, small size, and ability to measure low doses of radiation. This review focuses on the structural properties of TLD materials, as well as their preparation, application, and adaptability. The review covers the various types of TLD materials, crystal structure, and properties, including energy response and fading characteristics. The different methods used to prepare TLD materials, such as solid-state synthesis, sol-gel synthesis, and solution growth methods, are discussed in detail. The review also includes a detailed discussion of the various applications of TLDs, including medical, environmental, and industrial radiation dosimetry. Extensive information on TLD is reviewed, and the TL characteristics that have a noticeable impact on the TL dosimetry potential for human and other purpose utilisation, such as mineral, oil, and gas resource investigation, can be done using natural and artificial TL signals. Information on TL measurement process requirements and the TL characteristics that have a noticeable impact on a compound TL dosimetry potential are also addressed. Finally, the review concludes by highlighting the adaptability of TLD materials to different dosimetry applications and their potential use in the future. [ABSTRACT FROM AUTHOR]

In this work, reduced graphene oxide-coated zinc borotellurite doped with erbium oxide nanoparticles denoted as ZBTEr (NPs)-rGO was studied as an approach to enhance the optical properties of glass materials. Herein, a melt-quenched technique was used to prepare the ZBTEr (NPs) glasses. A simple and inexpensive spray-coated technique was employed to deposit the rGO onto the glass surfaces directly. The morphological studies of ZBTEr (NPs)-rGO glass surfaces were investigated by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) meanwhile, the structural investigation of ZBTEr (NPs) glasses was revealed by X-ray diffraction (XRD) and Raman analysis. The morphological analysis revealed the residual oxygen groups functionalized on ZBTEr (NPs)-rGO glass surfaces meanwhile, TEM images confirmed the presence of Er (NPs) in the glassy matrix. The glass samples showed the existence of structural disorder and amorphous nature. The absorption spectra presented the transition bands that existed from 4I15/2 ground state level to excited state levels of 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I11/2, and 4I9/2, respectively. Judd–Ofelt analysis was performed to obtain the intensity parameters (Ωλ), radiative transition (A), branching ratios (βR), and radiative lifetimes (tr). The radiative parameter and branching ratio values suggested the higher stimulated emission radiative at 2H11/2 → 4I15/2 transition for present glass The luminescence spectra exhibited two emission peaks centred at 539 nm and 558 nm which were assigned to 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions, respectively. The optical results for ZBTEr (NPs)-rGO and ZBTEr (NPs)-uncoated were compared to determine the differences between coated and uncoated glasses. These results highlight the significant effect of rGO deposited onto tellurite-based glass and thus, this work proposed the potential coating materials for improving current fiber optics. [ABSTRACT FROM AUTHOR]

(80-x)B2O3-xTeO2-10Li2O-Al2O3 (x=10-60 mol%) mixed glass former (MGF) glasses were prepared by using melt-quenching method to investigate the effect of mixed glass former between B2O3 and TeO2 on the optical properties and to evaluate the radiation shielding ability of the glass. Extremes observed at x=40 mol% for all optical properties' parameters were suggested due to large number of non-bridging oxygen. The radiation shielding properties of the glass samples were determined for 0.284 MeV-1.333 MeV energy range by using Phy-X/PSD software. The studied radiation parameters have shown enhancement due to high density and high atomic number, Z of Te over B. [ABSTRACT FROM AUTHOR]

Introduction & Objektif : The aim of the present work is to investigate the effect of radiation on methacrylic acid (MAA) crosslinked with N, N'-methylene-bisacrylamide (BIS) for the purpose of developing a polymer gel dosimeter, namely, Polymethacrylic gel (PMAAG). PMAAG of different concentrations of MAA and BIS were irradiated using _-rays produced by 60Co radionuclide with the absorbed doses ranging from 0 Gy to 19 Gy. Methodology : Due to the radiation-induced polymerization processes, the formation of Polymethacrylic gel (PMAAG) occurs, which causes the dose response mechanism increased in the Nuclear Magnetic Resonance (NMR) relaxation rates of protons. The relaxation rate R2 (1/T2) are fitted to the functional form y as a function of absorbed dose D was found to have a monoexponential expression in the form; y=y0 +A(1-e -D/D0). Results : The relaxation rate (_R2) dose sensitivity value (12.5 ± 0.1 Gy) of MAA monomer by Lepage, et al 2001 is comparable with PMAAG experimental value gained which are 12.6 ± 0.1 Gy. The dose sensitivity, D0 and half dose, D1/2 was found increasing with the concentrations of MAA monomer and BIS crosslinker. The slope parameter kBIS > kMAA indicates that consumption of crosslinker is much faster than monomer. Eventually, UV-Vis spectrophotometer was used to records PMAAG degree of absorption. The PMAAG has a mean value of absorption of 0.614 at 375 nm. The dose derived from PMAAG is comparable to Fricke dosimeter and ionization chamber readings between 4.7 ± 0.1% and 11.6 ± 0.1%. The dose errors of less than 10 ± 0.1% are considered acceptable in radiation processing, an improvement of accuracy less than 5.0 ± 0.1% is acceptable in radiotherapy. Conclusion : This effort is to undertake the study of precision and accuracy associated with the use of Fricke and polymer gel in optimizing the usage of gels for dosimetry. Based on the basic principle of dosimetry, a dosimeter must be both reliable and accurate, which its calibration should be traceable to a national or international standard. [ABSTRACT FROM AUTHOR]

Graphene-based nanomaterials offer superior properties especially in optical performance. The existence of oxygen functionalized group in graphene active layers is beneficial to enhance the optical properties of current tellurite glass. In this work, two series of glasses denoted as ZBTEr (uncoated) and ZBTEr-GO (coated) were successfully prepared using melt-quenching and low-cost spray coating techniques. X-ray diffraction analysis was done on both glass series and confirmed the amorphous structural arrangement in the glass system. Morphological study was investigated by using Scanning Electron Microscopy (SEM) and revealed the distribution of graphene layers on the glass surface. The UV-Vis spectroscopy was carried out and several absorption bands were determined for both series of glasses. The computation of oxide ion polarizability and optical basicity were investigated based on Lorentz-Lorentz equation. The oxide ion polarizability and optical basicity for ZBTEr-GO (coated) glasses were found higher than ZBTEr (uncoated) glasses due to the existence of sp2 graphitic attached on the oxygenic functional groups in GO layers. The metallization criterion values for ZBTEr-GO (coated) glasses were found decreased and tend to be more metallic. Hence, the deposition of graphene layers on the tellurite glasses offer a new strategy to improve the current telecommunication devices. [ABSTRACT FROM AUTHOR]

This paper aims to compare the structural and optical properties of ternary Boro-tellurite glass with the addition of two different chemical modifier. Six glass samples from composition [(TeO2)0.7 (B2O3)0.3]1-x (BaO)x (x = 0.10, 0.20 and 0.30 mol%) and [(TeO2)0.7 (B2O3)0.3]1-x (Bi2O3)x (x = 0.10, 0.20 and 0.30 mol%) were prepared by melt quenching method with suitable melting and quenching temperature. The X-ray diffraction (XRD) pattern confirms the amorphous nature of all glasses and the Fourier transform infrared spectroscopy (FTIR) spectra explore the fundamental groups and the local structural units in two different boro-tellurite glasses. The density for both glass series increased as barium oxide and bismuth oxide content increased. The optical band gap, Eopt values for bismuthboro- tellurite glasses are between 2.15-2.4 eV, while barium-boro-tellurite glasses are between 2.25-2.44 eV. The highest concentration of Bi2O3 in glass system shows the smallest Eopt. In conclusion, the obtained results shows that the addition of bismuth oxide in boro-tellurite glass improves its structural and optical properties. [ABSTRACT FROM AUTHOR]

Introduction : Acrylic monomers based polymer gel dosimeter incorporated with magnetic resonance imaging (MRI) potentially used in 3D dose distributions of radiotherapy modalities will be discussed. The polymerization of the dosimeter is commonly studied indirectly using water proton relaxation rate by nuclear magnetic resonance (NMR) and directly using Raman scattering of light due to covalent bonds of the polymer. The sensitivity of polymer gels to oxygen has been discussed extensively, and several investigators have responded by developing gels that contain oxygen scavengers, such as the MAGIC gel. The oxygen scavenger removes oxygen present in the gel at the time of manufacture, even if this is done in normoxic conditions. It can remove additional small amounts of oxygen, but ultimately will be overwhelmed if exposure to normal atmosphere is ongoing. While this problem has been addressed, it still creates minor inconvenience that might limit the successful introduction of gels into routine clinical use. Objektif : In this research we proposed to use of 2-Hydroxyethyl Acrylate (HEA) and 2-Hydroxyethyl Methacrylate (HEMA), N, N'-methylene-bis-acryalmide (BIS) as cross-linker, ascorbic acid as an anti-oxidant with gelatin-based formulation. Methodology : In polymer gel dosimeters, acrylic monomers are distributed homogeneously in a water-based gelatine matrix. When irradiated with ionizing radiation, polymerization restricted to the irradiated area is induced in the gel. Results : As a result of the polymerization, a number of gel properties (e.g., the NMR relaxation rates of water protons in the gel) are altered. The response to absorbed dose can thus be evaluated using, e.g., magnetic resonance imaging (MRI), optical tomography, x-ray computed tomography (x-ray CT), FT-Raman spectroscopy or ultrasound. In this research we use Raman spectroscopy for the data analysis. Conclusion : The dose sensitivity of polymerization can been determined directly using photon inelastic scattering of Raman spectroscopy by following the change of the Raman shift intensity at CH2, CH3 and C=O stretching peaks for polymer formations and at C=C stretching peak for monomer and cross-linker consumptions. [ABSTRACT FROM AUTHOR]

The aim of this work was to study radiation and the effects of temperature on conductivity properties of polyvinyl alcohol (PVA)-based potassium hydroxide (KOH) and propylene carbonate (PC), where the ionic conduction preferentially occurs in the amorphous phase by free radicals ions through gamma-irradiation. Alkaline composite polymer electrolyte (ACPE) consisting of PVA, KOH and PC of different concentration ratios were prepared by solvent-casting technique. The ACPE were irradiated with different doses from 5 kGy up to 200 kGy. The conductivity properties of the electrolyte films were measured at different frequencies in the range 20 Hz to 1 MHz using LCR meter. The results showed that the conductivity properties were dependent on the radiation dose, temperature and the concentration of the polymer blends.

The radiation-response characteristics of polymetharylic acid gel dosimeter prepared with different concentrations of monomer and cross-linker is described in these studies. The dosimeters were prepared under the hypoxic condition in a glove box and were then irradiated with gamma-rays produced by Co-60 radionuclide that was generated at 1.25MeV energy. The irradiation took place at different doses ranged from 0Gy to 19Gy. Due to the radiation activities, chain-reaction polymerisation processes had taken place in the formation of polymethacrylic acid (PMAA) gel, which cause the dose response mechanism increased in the NMR relaxation rates of protons. It has been observed that for higher concentration of monomer and cross-linker, the polymerization rate was increased.

Poly (p-phenylene vinylene) (PPV) was synthesized from p-xylylene bis(tetrahydrothiophenium chloride) using the Wessling route and characterized by Fourier Transform Infra-Red (FTIR) and UV-visible (UV-VIS) spectroscopic techniques. The significance of thermal treatment along with evolution of precursor polymer to polymer PPV was also studied through these spectroscopic techniques. Thermally Stimulated Current (TSC) measurements indicated the presence of crystallization, sulphonium group which occurred through the evolution from precursor polymer to polymer PPV during thermal treatment.