Thermoluminescence Features Research Articles

Synthesis and thermoluminescence characterization of either Cu- or Ag-doped lithium triborate

Lithium Triborate (LiB3O5 or LTB), is characterized by chemical stability and good mechanical properties, and it has an effective atomic number (Zeff = 7.39) close to that of the human tissue (Zeff = 7.42), making it a potential dosimeter. The objective of this research is to examine the Thermoluminescence (TL) features and dosimetric characteristics of both Cu-doped and Ag-doped LTB. The material was synthesized using the solid-state synthesis method and four different dopant levels were used for each element (0.1%, 0.5%, 1%, 3%); various techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used for structural and compositional characterization, for samples annealed at 500 °C for 1 h in all cases. Specific TL features were studied, such as TL glow curve shape, sensitization and sensitivity, fading behavior as well as kinetic characterization using two supplementary techniques, namely fractional glow technique and deconvolution analysis. The effect of each dopant element is different in the (same) lithium triborate matrix in terms of sensitivity. TL dosimetric peaks are yielded for both dopant elements; however, the optimum doping level is 3% for Ag but just 0.1% for Cu. Furthermore, the samples were irradiated at different doses, ranging from 0.5 to 2048 Gy, in order to study the corresponding dose response. A remarkable dose response linearity was observed for the main dosimetric peak of both materials, ranging up to ∼1 kGy.The fading results suggest that LTB doped with 0.1% Cu is the most promising material for dosimetric applications.

Exploring the thermoluminescence characteristics of smartphone screen safety glasses for retrospective dosimetry applications

In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2–10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (μg) is found to be within the range of 0.43–0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (E) and frequency factor (s) are found in the range of 0.31–0.54 eV and 4.55 × 103 to 2.12 × 106 s−1 respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.

Thermoluminescence kinetics in beta-irradiated novel ZnGa2O4:Eu3+ phosphor produced via gel combustion synthesis

Eu3+ doped ZnGa2O4 phosphors with varying dopant concentrations were successfully synthesized using the combustion technique. X-ray diffraction analysis confirmed the consistency of both undoped and Eu3+ doped ZnGa2O4 samples with PDF#38–1240 card structure. The investigation of thermoluminescence (TL) characteristics involved studying TL glow curves in Eu3+ doped ZnGa2O4 samples with different dopant concentrations, employing various optical detection filter combinations. Among these, ZnGa2O4: 2%Eu3+ and the IRSL-TL wide blue band (wbb) proved to be the optimal sample and ideal detection filter pairing for identifying TL features. Following preheating experiments, the TL maximum was observed at around 190 °C, with a heating rate of 2 °Cs−1. The dose-response experiment for ZnGa2O4:2%Eu3+ exhibited satisfactory linearity, with a coefficient of b = 0.988 and an R2 value of 0.989 for doses up to 100 Gy. Moreover, for the dose range of 200–500 Gy, a sublinear relationship was maintained, with a coefficient of b = 0.31 and an R2 value of 0.988. Hoogenstraaten's method, along with the initial rise method and the Tm-Tstop experiment, was also employed in conjunction with a glow curve fitting package. This comprehensive approach facilitated the determination of the number of peaks, trap structure, and kinetic parameters within the thermoluminescence glow curve. Glow curve deconvolution using specialized software revealed the presence of five well-isolated and overlapping TL glow peaks, achieving a figure of merit (FOM) value of 1.39.

Thermoluminescence studies of Pakistani limestone pellets for X-rays

The quest to identify low-cost thermoluminescence (TL) materials is vital, and the identification and assessment of natural materials suitable for radiation detection is a rapidly growing area of research. In addition to their specific dosimetric characteristics, such materials must be rigid, insoluble, and chemically inert. One such promising low-cost material can be a limestone having vast deposits in Pakistan. The present study reports the TL and dosimetric features of Pakistani limestone pellets and their comparison with TLD-100.The quarried crystalline limestone rock was hand crushed, sieved, and compressed into the standard TLD chip-sized pellets. The TL response, kinetic parameters, batch homogeneity, dose linearity, individual sensitivity correction factor (i.e., elemental correction coefficient ECC), lowest detectable dose limit (LDDL), coefficient of variation (COV), energy dependency, and fading were determined, and compared with TLD-100. For TL analysis, the pellets were exposed to an 8 Gy dose of 250 kVp X-rays. These exhibited complex TL showing four peaks (P1: 90–110 °C, P2: 130–170 °C, P3: 240–280 °C and P4: 320–350 °C). The limestone response was linear in the studied dose range of X-rays (1–10 Gy), unlike the supra-linear behavior of TLD-100. The kinetic parameters (i.e., the frequency factor (f), activation energy (E), and the kinetic order (b)) were estimated through computerized glow curve deconvolution using the general order of kinetics while confirmed by the Tm-Tstop method. The values of E and f were observed in the ranges of 0.85–1.27 eV and 5.98 × 107 to 1.81 × 1013 s−1, respectively. The calculated value of figure-of-merit (FOM) (i.e., 2.37%) showed a good agreement between the experimental and fitted glow curves. The overall variation in the ECCs for TLD-100 and limestone was found within ±4% and ±7%, respectively. The results of the ECC confirmed batch homogeneity. The calculated value of LDDL was ∼1.01 Gy. The investigation found that the maximum variation in normalized intensity and COV was within the tolerance limit of 5%. The limestone pellets showed less sensitivity than TLD-100. Like TLD-100 at high energy, the pellets showed an independent response. In contrast to TLD-100, the limestone pellets showed a higher response dependency for low-energy X-rays.During the fading study, the total TL intensity decreased by 20% within the initial 24 h of irradiation and then sustained stability for the subsequent week. The results of this study indicate that limestone pellets are effective as an X-ray dosimeter for doses between 1 and 10 Gy.

Beta particle excited thermoluminescence of new ZnO:Ce phosphors

This work reports on the beta particle excited thermoluminescence (TL) of ZnO:Ce phosphors, synthesized through a controlled chemical precipitation reaction followed by thermal annealing at 900 °C in an air atmosphere during 24 h. The successful obtention of crystalline hexagonal zincite structure was confirmed by X-Ray diffraction. By milling ZnO:Ce powder precipitated during the reaction before carrying out the thermal annealing, there are improved reproducibility and enhanced TL features of interest for dosimetry. Ce doping strongly increases the TL sensitivity and leads to a simpler glow curve shape. The TL – dose response exhibits a linear behavior at least up to 128 Gy. The sensitivity of the synthesized ZnO:Ce is ca. 103 times greater than that of undoped ZnO. The TL fades 22% two days after radiation exposure, and then it becomes negligible.

Synthesis, structural characteristics and thermoluminscence features of KCl:Mn and KCl:Ce phosphors

Manganese and cerium doped potassium chloride (KCl:Mn and KCl:Ce) were produced by the co-precipitation method with ultrasonic waves. Characterization of the samples material was carried out using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS) patterns. The optimum amount of manganese and cerium concentration with the most thermoluminescence (TL) sensitivity was obtained at 0.3 mol% in KCl:Mn and 0.5 mol% in KCl:Ce samples. To evaluate the number of component glow peaks and the kinetic parameters of the TL glow curve of synthesized materials, computerized glow curve deconvolution (CGCD) and Tm-Tstop methods were used. The thermoluminescence properties of phosphors were studied at different doses. The TL response was linear in the range of 10–1000 Gy. Other TL features of the prepared material are also discussed.

Thermoluminescence response and trap features of gamma-irradiated Sr2Al2SiO7:Dy3+ phosphors

This study mainly focuses on the thermoluminescence features and trap parameter analysis of Sr2Al2SiO7:Dy3+ phosphors prepared via the low-temperature combustion method. The phase confirmation, structural and morphological studies are performed using XRD, FTIR, SEM and EDX characterizations. The energy gap of pure and Dy3+ doped phosphors is calculated. And the band gap decrease with doping. The optimum concentration was 3 mol% from the emission spectra; hence, this sample was irradiated with 3 Gy–5 kGy gamma doses. The samples showed high sensitivity and the MDD value is 0.21 mGy. The trap parameters were determined following deconvolution of the glow curves. Four traps were found in the samples, and the trap lifetime increased with increasing gamma dose. The trap depth increased The linear response from 3 Gy to 250 Gy implies that the prepared samples could be used as γ dosimeters within this range.

Preparation and characterization of Li2B4O7 nanoparticles co-doped with Mg and Cu for thermoluminescence dosimetry of gamma-rays

Lithium tetraborate nanoparticles co-doped with various percentages of Cu and Mg impurities were synthesized through the combustion process. Scanning electron microscopy images along with X-ray diffraction patterns confirmed the shape and structure of the products. Williamson-Hall equation was used to measure the nanoparticles size that resulted in approximately 55 nm for the crystallite size. The optical band gap of about 3.7 eV was obtained for the nanostructures from the UV–visible spectrum. Furthermore, the thermoluminescence features of the samples under gamma irradiation were studied at ambient conditions. The highest thermoluminescence sensitivity was achieved at 0.02 % wt Cu and 0.5 % wt Mg impurities simultaneously. The results show that the co-doped nanoparticles have a linear dose-response up to an administrated dose of 30 kGy. About 10% of the thermoluminescence signal fades after 30 days of storage at room temperature.

Classification of thermoluminescence features of the natural halite with machine learning

Radiation dosimeters are used to measure the absorbed radiation dose of any living organism during the time intervals. They include defective crystals that store radiation until they are stimulated. Thermoluminescence (TL) is a way to see the absorbed dose of the dosimeters. The irradiated crystal is heated up to 500°C to reveal the absorbed dose as a luminescence light. The TL dosimetric properties of natural halite (rock-salt) crystals extracted from Meke crater lake in Konya, Turkey, were investigated in this study. Support Vector Machine (SVM), Artificial Neural Network (ANN) and K-Nearest Neighbor (K-NN) were also examined utilizing machine learning for categorization of TL characteristics. According to the experimental output, the TL glow curve has two main peaks located at 100 and 270°C with good dosimetric properties. In the three classifiers, SVM has the biggest accuracy and precision. High training-low testing and results from normalized data give the best accuracy, precision, sensitivity and F-score.

Investigation on structural and thermoluminescence properties of Ho3+doped SrB4O7 phosphor for dosimetry applications

A series of tissue equivalent novel Sr(1-x)B4O7:Hox (0 ≤ x ≤ 0.5 mol%) phosphors have been synthesized via solid state diffusion to investigate their structural and Thermoluminescence features. The rietveld refinement of XRD data confirms pure phase formation with an orthorhombic crystal structure. FTIR and Raman spectroscopy have been used to examine the vibration characteristics and bonding among each constituent of material. The analysis detected bending vibrations of bridging oxygen's within B-O-B bonds in BO3 trigonals, alongwith stretching vibrations of [BO4] tetrahedral. SEM was used to inquire the surface morphology as well as to record EDX patterns for authentication of the elemental composition in all the samples. The microphosphors possess a dense structure with irregularly shaped grains with an average grain size of 1.36–1.45 µm. The TL glow curves have been recorded to evaluate the dosimetric properties of γ-exposed phosphors i.e. dose response, fading and reproducibility. Doped samples exhibit higher TL sensitivity as compared to pure samples. The critical holmium concentration for TL was found to be 0.5 mol%. Fading was examined and the TL intensity of the predominant dosimetric TL Peak of SB3 sample was determined to be a -12% decline after 15 days. Repetitive analysis demonstrates that SrB4O7 have high reproducibility. The phosphors exhibit a linear dose response and good reproducibility, with a standard deviation of ∼2%. The trapping parameters (viz. E, b and s) have been computed using PS, IR and Ilich methods. The dosimetric attributes of the novel fabricated phosphors acknowledge their adequacy for dosimetry applications.

An examination of the radiation-induced defects and thermoluminescence characteristics of Sm2O3 doped BaO–ZnO–LiF–B2O3 glass system for γ-dosimetry application

10BaO–20ZnO–20LiF-(50- x )B 2 O 3 - x Sm 2 O 3 ( x = 0, 0.1, 0.3, 0.5, 0.7, and 1.0 mol %) glasses were synthesized with an objective to examine the γ-radiation-induced defects and Thermoluminescence (TL) characteristics towards potential TL dosimetry application. The addition of 0.1 mol % Sm 2 O 3 to the host glass led to a drastic enhancement (almost two thousand times) in the TL intensity and concentration quenching was seen thereafter. The Sm 2 O 3 concentration and γ-dose for the examination of defects and TL features were optimized to be 0.1 mol % and 3 kGy, respectively. The lack of distinct peaks in the X-Ray Diffraction pattern confirmed the glass amorphous nature. The structural modification after irradiation was conveyed in the optical absorption spectroscopy by the presence of color centers and in Fourier Transform Infrared spectroscopy by the increase in the Non-Bridging Oxygens. The color centers were identified as Non-Bridging Oxygen Hole Center and Boron E ’ -center from the Electron Spin Resonance characterization. The glass manifested a good linear TL response between 0.25 and 3 kGy, high sensitivity, a minimum detection dose of 2 ± 0.2 Gy, reusability and reproducibility after annealing at 523 K for 15 min, Z e f f of 9.6, and trap activation energies between 0.47 and 1.28 eV. The application of the titled glass system as a potential TL dosimeter is proposed for food irradiation, and γ-environment (up to 3 kGy). • Sm 2 O 3 doped BaO–ZnO–LiF–B 2 O 3 glass system investigated for γ-TLD characteristics. • Two thousand times enhancement in TL intensity after 0.1 mol % Sm 2 O 3 incorporation. • TL characteristics suitable for high-dose γ-dosimetry (0.25–3 kGy). • Color centers post-irradiation evaluated through optical and structural properties.

Classification of thermoluminescence features of CaCO3 with long short-term memory model.

Calcium carbonate (CaCO3 ), a mineral commonly found in the Earth's crust, is mainly in the forms of calcite and aragonite. Calcite has the most stable type of thermodynamics at room temperature and ambient pressure. It has wide band gap structure and is of great interest for a wide-range technical and industrial applications due to its physical properties and suitability. In this study, a new method based on the long short-term memory (LSTM) model of deep learning is proposed to classify the thermoluminescence properties such as fading, cycle of measurement, heating rate, and dose-response of CaCO3 . Therefore the thermoluminescence properties of calcite was investigated as a suitable band structure and its coherent data were used to classify the features using a deep learning LSTM model. Experiments were carried out on a dataset consisting of four classes. The accuracy, precision, and sensitivity values of the proposed model obtained were 98.34, 97.90, and 98.56%, respectively. The classification process of the results obtained from the designed model showed good performance.

Structural and luminescent properties of aluminum‒based nanophosphors

This work presents the structural impacts of the crystalline micro and nanoparticles co-doped aluminum oxide on their thermoluminescent features. For this purpose, Ca9Al (PO4)7 with different Cr and Si concentrations was prepared and the best in TL-response in this batch was selected for further study which was Ca9Al (PO4)7: 2 Cr, 8 Si mol%. Additionally, Al2O3 co-doped with different dopants was synthesized. Al2O3: 0.005 (P, Ca, Cr, Si) mol% showed the higher TL-response in this batch and was selected for further study. The surface morphology and uniform distribution of the elements of the selected samples were confirmed using scanning electron microscopy (SEM) with Energy Dispersive X-ray scattering (EDX) analysis. X-Ray Diffraction (XRD) and transmission electron microscope (TEM) results reflected the existence of the nanoparticles structure with average sizes of 22.7 and 35.13 nm for Ca9Al (PO4)7: 2 Cr, 8 Si mol% and Al2O3: 0.005 (P, Ca, Cr, Si) mol%, respectively. Photoluminescence (PL) spectrum at λex = 304 nm shows emission at range of 370–600 nm and at 825 nm for both samples. Good linear dose-response relationships were found in dose range of 3 up to 20 Gy. But, the TL-response of Al2O3: 0.005 (P, Ca, Cr, Si) mol% structure was about 22 times higher than that of the Ca9Al (PO4)7: 2 Cr, 8 Si mol% one. Therefore, introducing P and Ca as a co-dopants with Cr and Si in Al2O3: P, Ca, Cr, Si highly increased its TL-response. This reflected the structural dependence of the studied samples on their TL-responses.

Thermoluminescence features of Er3+ doped BaO-ZnO-LiF-B2O3 glass system for high-dose gamma dosimetry

Transparent 10BaO-20ZnO-20LiF-(50-x) B2O3-xEr2O3 glasses with x = 0, 0.1, 0.5, 0.7 and 1 mol % were synthesized using melt-quench method. Their amorphous nature was confirmed from X-Ray Diffraction (XRD). The glasses were irradiated with 3 kGy gamma dose, among which the sample with 0.7 mol % Er2O3 doping showed the highest integrated thermoluminescence (TL) intensity. The dose-response was evaluated by irradiating the sample with 0.25- 30 kGy gamma doses. The highest integrated TL intensity was obtained at 3 kGy dose. Fourier Transform Infrared (FTIR) spectra of the 0.7 mol % Er2O3 doped glass after 3 kGy gamma irradiation predicted the creation of new bonds and rise in the Non-Bridging Oxygens. UV–Vis–NIR absorption spectra recorded after 3 kGy gamma irradiation accounted for the formation of color centers due to an increase in the total absorption of the glass, a decrease in the bandgap and an increase in the Urbach energy. The sample exhibited good linearity in the 0.25 to 3 kGy range with high sensitivity of 27021 counts g-1kGy-1 and a minimum detectable dose of 0.201 kGy. TL signal faded by just 4% after a week of storage. The annealing condition for reusability and the effective atomic number of the glass were examined. Trap parameters like activation energy, frequency factor and lifetime, determined using Computerized Glow Curve Deconvolution (CGCD) and Chen's peak shape methods supported the low fading of the sample. Overall, the remarkable TL dosimetry characteristics present the usefulness of the titled glass system in radiation processing of food products and high-dose (0.25 to 3 kGy) gamma environment.

A study on thermoluminescence behaviour of Eu doped LaB3O6 irradiated with beta particles

Lantanium triborate (LaB3O6) samples doped with Eu3+ ions are synthesized via combustion route. This study primarily reports the thermoluminescence (TL) behaviour of LaB3O6 host. X-ray diffraction (XRD) pattern reveals that LaB3O6 exhibits a single phase matched with JCPDS card 98-002-3609. Dose response, reusability and trap parameters of TL glow curves are evaluated to clearly reveal the TL features. The results show that the peak positions of TL glow curves are affected by varying the concentration of Eu. The experimental results obtained from the dose-response of LaB3O6:Eu3+ (1%) which has given high TL intensity reveal that the intensity of TL given by the total area under glow curves shows a good linearity (b= 0.997) up to 20 Gy. In addition, the minimum detectable dose (MDD) value has been calculated as 1.45 mGy with a standard deviation of 0.8%. Main TL peak maxima is observed around 197 °C with heating rate (HR) of 2 °Cs−1. An anomalous HR effect is observed for this peak in the range of 0.5–20 °Cs−1 with beta dose of 5 Gy. To find the overlapping peak numbers and determine the kinetic parameters of the main peak of LaB3O6:Eu3+ (1%), Initial Rise (IR) method using Tm−Tstop experiment and CGCD analysis have been performed for HRs of 0.5 and 2 °Cs−1. It can be said that the results of the methods are in good agreement when same trap numbers (at least eight separate peaks for both) and close energy values are taken into consideration. Deconvolution procedure of LaB3O6: Eu3+(1%) is performed using general order kinetic equation by R studio ‘tgcd’. Additionally, the lifetimes of each deconvolved peaks by CGCD of Eu activated LaB3O6 (1%) have been calculated. Based on the results it can be put forth that TL characteristics of Eu doped LaB3O6 can be used as a promising material for thermoluminescence dosimetry-environmental applications.

Thermoluminescence features of commercial glass and retrospective accident dosimetry

Five window glass brands popularly used in Bangladeshi dwellings have been analyzed for retrospective accident dosimetry, being inexpensive, highly effective as a barrier to moisture and naturally transparent at optical wavelengths. In examining their potential for dosimetry, study has been made of the annealing – irradiation - readout steps contributing to characterization of the various key thermoluminescence properties. These include the respective glow curves, relative sensitivity, dose response, energy response, reproducibility and fading. An ERESCO model 200 MF4-RW X-ray machine and a Gammacell-220 60Co source was used for sample irradiation, while a Harshaw 3500 TLD reader (USA) supported by WinREMS software was used for TL readouts. Within the γ-radiation dose range up to 50 Gy, the various TL parameters show Nasir glass (a locally produced glass brand) to offer the most promising performance for retrospective dosimetry. Fading studies indicate the reconstruction of absorbed dose to be possible for periods of up to four weeks post-exposure. Energy dispersive X-ray analysis shows the Zeff of the various glass to be in the range 12.5–15.1, closely according with that of TLD-200, a commercial dosimeter used for low-level environmental radiation dosimetry. Present work constitutes the first such study of low-cost commercial glass for doses in the range 10–50 Gy, previous literature relating to doses from 50 Gy up to 20 kGy.

Comparative studies on thermoluminescence characteristics of non-doped Mg2SiO4 prepared via a solid-state reaction technique and wet-chemical method: An unusual heating rate dependence

Magnesium orthosilicate (Mg2SiO4) was synthesized via a traditional solid-state reaction and a wet chemical route. This study primarily reported the thermoluminescence (TL) behavior of Mg2SiO4 host. X-ray diffraction pattern revealed that Mg2SiO4 exhibits orthorhombic structure matched with JCPDS card 900-6398. Dose response, reproducibility and trap parameters of TL glow curves were evaluated to clearly reveal TL features. Two TL glow peaks situated at 81 °C and 192 °C were monitored at a heating rate of 2 °Cs−1. We observed anomalous heating rate effect for the peak centered at 192 °C whilst TL intensity of the peak at 81 °C decreases with elevating heating rate. Trap depths of the electrons within the trap centers were found to be 1.04 ± 0.01eV and 1.37 ± 0.01eV for both methods using peak shape (PS) method. Distribution of trap centers was examined using the Tmax−Tstop method and this case indicated that the glow curves consist of single TL peaks. The intensity of TL glow curves exhibited a good linear dose response under total area up to 20 Gy. A comparison of the two preparation techniques revealed that TL characteristics of this phosphor are partly dependent and Mg2SiO4 could be a promising material for dosimetric application.

Thermoluminescence analysis of beta irradiated ZnB2O4: Pr3+ phosphors synthesized by a wet-chemical method

In this paper we describe the thermoluminescence (TL) characteristics of ZnB2O4:Pr3+ phosphors with Pr concentrations varying between 0.2 and 1 mol% prepared by a wet-chemical method. The TL glow curves of the phosphor sample consisted of three peaks located at 71 °C (P1), 124 °C (P2) and 233 °C (P3). The TL intensity increased with the beta dose ranging from ∼0.1 to ∼20 Gy. Dose response, reproducibility and trapping parameters of TL glow curves were evaluated to clearly reveal thermoluminescence features. We observed that TL intensity of P2 and P3 peaks decreases as the heating rate increases. Trap parameters were estimated via the Hoogenstraaten, Booth-Bohun-Parfianovitch, the initial rise methods combined with Tm−Tstop experiment and TLanal CGCD program. Heating rates were varied to use in the Hoogenstraaten analyses. The Tm−Tstop investigations on regenerated TL signals for P1 and P2 peaks indicated that ZnB2O4:Pr3+ phosphor has four electron trap levels with energy values in the range of 0.5–1.5 eV These four traps have first order kinetic and are formed at high temperature region. Resulting values are utilized as a reference for the CGCD procedure and the trapping parameters from the TL glow curves are calculated. The figure of merit (FOM) of the TL glow curve during curve fitting procedures is found to be 2.019%. The intensities of the main dosimetric peaks appeared at 124 °C and 233 °C exhibits good linear dose response up to 20 Gy. These results provide valuable knowledge for use of the characteristics of Pr doped ZnB2O4 in dosimetry research, just need to eliminate low temperature TL peak.

Synthesis and thermoluminescence characterization of self-agglomerating CaSO4 exposed to beta radiation

The synthesis and thermoluminescence (TL) characterization of self-agglomerating pellet-shaped CaSO4 phosphors, through a low cost and environmentally friendly method is reported. In order to investigate their TL features, some samples were exposed to beta particle irradiation in the dose range from 0.07 to 10 Gy. Characteristic TL glow curve consists of a single main maximum located at 216 °C, which is considered stable, hence, suitable for dosimetry applications. The dose-response was remarkable linear. Moreover, the lower detection limit was determined to be 6.0 μGy, and the relative TL sensitivity twice the one from the commercial TLD-100 dosimeter.

The effect of water on the thermoluminescence properties in various forms of calcium sulfate samples

The present study investigates whether thermoluminescence (TL) features are prevalent over calcium sulfate samples, regarding their lever of hydration. Three groups of calcium sulfates -dihydrate (gypsum), hemihydrate (bassanite) and anhydrous (anhydrite)- are investigated, of both commercial and mineral origin. The study includes TL features such as TL glow curve shapes, the stability of TL peaks after successive cycles of measurements, and the estimation of the kinetic parameters of stable TL peaks. Moreover, the slurry of calcium sulfate with water is being studied, to investigate its prevalence as an effective zeroing mechanism. The results indicate the presence of stable TL peaks around 280 °C for all of the groups of calcium sulfates, while the TL sensitivity of the samples depends on their water content and stabilizes after three heating cycles up to 500 °C. Anhydrite shows stability even from the initial measurement, while the hemihydrates and dihydrates could be used for dating applications using TL by means of a multiple aliquot protocol.