A systematic study on luminescence characterization of lanthanide-doped BeO ceramic dosimeters

This work aimed to investigate the luminescent characteristics of lanthanide and alkali metal ion-doped BeO ceramic pellets prepared using the co-precipitation synthesis technique for Optically Stimulated Luminescence (OSL) dosimetry applications. In this study, BeO nano phosphor was doped with lanthanides (Ln(3+)) Eu3+, Ce3+, Nd3+, Yb3+, Er3+, Gd3+, Tb3+, Tm3+, Sm3+, Pr3+, and Dy3+ and co-doped with Na+, and characterized using radioluminescence (RL), thermoluminescence (TL) and OSL techniques. Lanthanides introduced as dopants not only affected the luminescence centers but also changed the luminescence mechanisms. The RL spectra of lanthanide-doped BeO samples showed that they mostly possess dominant emissions in the narrow bands (between 200 and 450 nm) in the UV region. OSL emission bands were found to be located between similar to 250 and similar to 390 nm. The results have demonstrated that the incorporation of appropriate Ln(3+) and alkali metal ion dopants and their optimum concentrations enhanced the luminescence intensity of undoped BeO. The studied BeO:Na-5%,Ce-0.01%,Er-0.01%, BeO:Na-5%,Ce-0.005%,Tb-0.05%, and BeO:Na-5%,Ce-0.01%,Dy-0.01% ceramics can be regarded as highly sensitive controllable luminescence dosimeters. The range of sensitivity of those samples is such that their most probable use in clinical therapy dosimetry rather than in health physics. (C) 2021 Elsevier B.V. All rights reserved

Radiation dosimeter utilizing optically stimulated luminescence of BeO:Na,Tb,Gd ceramics

This paper presents a systematic study of a new Optically Stimulated Luminescence (OSL) dosimeter based on BeO:Na,Tb,Gd ceramics synthesized using precipitation method. We confirm the product performing X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) analyzes. Luminescence signals are characterized by Thermoluminescence (TL), Radioluminescence (RL), and OSL techniques. BeO:Na,Tb,Gd ceramics have two TL peaks located at ~180 and 370 °C associated with the OSL signals. Thermal quenching energies were evaluated as 0.52 eV using the OSL signals obtained at various readout temperatures and 0.55 eV using TOSL method. The results demonstrate that the OSL signals of BeO:Na,Tb,Gd ceramics with high sensitivity, dose linearity, low-fading, reusability, and thermal stability are very encouraging and convenient for medical applications. © 2019 Elsevier B.V.Mersin Üniversitesi FDK-2018-10190This research was supported by the Cukurova University Rectorate through the project FDK-2018-10190 . We are grateful to Cukurova University for financial support and to Prof. Kasım Kurt from Mersin University for RL measurements. Appendix

Studies of blue light induced phototransferred thermoluminescence in CaSO4:Mg

WOS: 000468251500006In this work, phototransferred thermoluminescence (PTTL) was observed in polycrystalline powder samples of Mg-doped CaSO4 (CaSO4:Mg) which were produced via the precipitation technique. The thermoluminescence (TL) glow curve showed the two separate main peaks. Composition of the peaks was at 90, 145, 180 and 235 degrees C and on the high temperature side, at 355, 410 and 475 degrees C with a 5 degrees C/s heating rate after delivering 100 Gy beta dose. The PTTL induced in CaSO4:Mg using blue light (470 nm) was reported and some PTTL characteristics were investigated. The PTTL intensity as a function of duration and temperature of illumination was recorded. As a function of increasing beta dose, a linear dose-response was obtained for the sample at 100 degrees C within the dose range from 1 to 150 Gy. The decaying of the PTTL signals of the previously irradiated sample was examined through successive blue light stimulation cycles. PTTL was used to determine dark fading of the material which was found stable with 2% loss of charge in the deep traps accessed by the PTTL measurement procedure. The thermal activation energy of the source traps involved in the PTTL was evaluated as 1.90 eV using the pulse annealing technique. Although these results showed that CaSO4:Mg presented a good PTTL performance and the blue light-induced PTTL signal can be used for dosimetry, it needs further study to understand the physical mechanisms associated with the transfer of charge from the deep traps probed by the PTTL measurements.Cukurova University Research Projects Development and Coordination Unit [FDK-2018-10599]; Cukurova UniversityCukurova UniversityThis research was partly funded by the Cukurova University Research Projects Development and Coordination Unit under the project number FDK-2018-10599. We thank Cukurova University for supporting the project

Effect of sintering temperature on dosimetric properties of BeO ceramic pellets synthesized using precipitation method

BeO material has been extensively explored owing to its excellent performance in the electronics industry and for interest in ionizing radiation dosimetry. In this study, BeO samples were prepared using precipitation method, pelletized and then sintered at temperatures 1200, 1400 and 1600 °C to afford dried pellets with better crystallinity and luminescence characteristics. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) results showed that the prepared pellets were polycrystalline in nature and crystallinity improved with the increase of sintering temperature. The X-ray (XL) luminescence spectra of BeO pellets sintered at 1200 and 1400 °C were obtained as a narrow peak in the region 200–350 nm with the maximum around 250 nm. The emission spectrum of the XL signal from 1600 °C sintered sample was obtained as a broad peak in the region 200–450 nm with two maximums around 250 and 300 nm. The optically stimulated luminescence (OSL) signals were observed for the preheating temperatures from 50 up to 500 °C. The OSL signal was found to originate from the TL traps near 170 and 275 °C for 1200 °C sintering temperature. While, the TL peaks at around 275 °C and 170 °C contribute to the OSL signals at the sintering temperatures 1400 and 1600 °C, respectively. It was investigated that the OSL signal exhibits strong thermal quenching. The thermal quenching energies were estimated as 0.61, 0.55 and 0.53 eV using the OSL signals obtained at various readout temperatures ranging from 50 °C to 110 °C and 0.57, 0.54 and 0.51 eV using the TOSL method, for the samples sintered at 1200, 1400 and 1600 °C, respectively. The dose responses of the total OSL signals are linear from 0.1 to 50 Gy for the sintering temperatures of 1200 and 1400 °C and 1600 °C. After the 24 h in which the shallow traps are responsible from the observed fading of the material, the fading of the total OSL signals was found as −3.1% and −4.3% associated with the 1200 and 1400 °C sintering temperatures, respectively. There was no fading with respect to the first reading for the samples sintered at 1600 °C. The present study may promote the application of BeO luminophore synthesized using precipitation technique and sintered at 1600 °C, in medical dosimetry.This research is sponsored by the Cukurova University Rectorate through the projects FDK-2018-10190. We gratefully acknowledge the financial support given by Cukurova University.Peer reviewe

Studies of blue light induced phototransferred thermoluminescence in CaSO 4 :Mg

In this work, phototransferred thermoluminescence (PTTL) was observed in polycrystalline powder samples of Mg-doped CaSO 4 (CaSO 4 :Mg) which were produced via the precipitation technique. The thermoluminescence (TL) glow curve showed the two separate main peaks. Composition of the peaks was at 90, 145, 180 and 235 °C and on the high temperature side, at 355, 410 and 475 °C with a 5 °C/s heating rate after delivering 100 Gy beta dose. The PTTL induced in CaSO 4 :Mg using blue light (470 nm) was reported and some PTTL characteristics were investigated. The PTTL intensity as a function of duration and temperature of illumination was recorded. As a function of increasing beta dose, a linear dose–response was obtained for the sample at 100 °C within the dose range from 1 to 150 Gy. The decaying of the PTTL signals of the previously irradiated sample was examined through successive blue light stimulation cycles. PTTL was used to determine dark fading of the material which was found stable with 2% loss of charge in the deep traps accessed by the PTTL measurement procedure. The thermal activation energy of the source traps involved in the PTTL was evaluated as 1.90 eV using the pulse annealing technique. Although these results showed that CaSO 4 :Mg presented a good PTTL performance and the blue light-induced PTTL signal can be used for dosimetry, it needs further study to understand the physical mechanisms associated with the transfer of charge from the deep traps probed by the PTTL measurements. © 2019 Elsevier B.V.FDK-2018-10599This research was partly funded by the Cukurova University Research Projects Development and Coordination Unit under the project number FDK-2018-10599. We thank Cukurova University for supporting the project. Appendix

Effect of sintering temperature on dosimetric properties of BeO ceramic pellets synthesized using precipitation method

BeO material has been extensively explored owing to its excellent performance in the electronics industry and for interest in ionizing radiation dosimetry. In this study, BeO samples were prepared using precipitation method, pelletized and then sintered at temperatures 1200, 1400 and 1600 °C to afford dried pellets with better crystallinity and luminescence characteristics. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) results showed that the prepared pellets were polycrystalline in nature and crystallinity improved with the increase of sintering temperature. The X-ray (XL) luminescence spectra of BeO pellets sintered at 1200 and 1400 °C were obtained as a narrow peak in the region 200–350 nm with the maximum around 250 nm. The emission spectrum of the XL signal from 1600 °C sintered sample was obtained as a broad peak in the region 200–450 nm with two maximums around 250 and 300 nm. The optically stimulated luminescence (OSL) signals were observed for the preheating temperatures from 50 up to 500 °C. The OSL signal was found to originate from the TL traps near 170 and 275 °C for 1200 °C sintering temperature. While, the TL peaks at around 275 °C and 170 °C contribute to the OSL signals at the sintering temperatures 1400 and 1600 °C, respectively. It was investigated that the OSL signal exhibits strong thermal quenching. The thermal quenching energies were estimated as 0.61, 0.55 and 0.53 eV using the OSL signals obtained at various readout temperatures ranging from 50 °C to 110 °C and 0.57, 0.54 and 0.51 eV using the TOSL method, for the samples sintered at 1200, 1400 and 1600 °C, respectively. The dose responses of the total OSL signals are linear from 0.1 to 50 Gy for the sintering temperatures of 1200 and 1400 °C and 1600 °C. After the 24 h in which the shallow traps are responsible from the observed fading of the material, the fading of the total OSL signals was found as -3.1% and -4.3% associated with the 1200 and 1400 °C sintering temperatures, respectively. There was no fading with respect to the first reading for the samples sintered at 1600 °C. The present study may promote the application of BeO luminophore synthesized using precipitation technique and sintered at 1600 °C, in medical dosimetry. © 2018 Elsevier B.V.FDK-2018-10190This research is sponsored by the Cukurova University Rectorate through the projects FDK-2018-10190. We gratefully acknowledge the financial support given by Cukurova University . We very much appreciate Prof. Enver Bulur for his valuable discussions and comments, Prof. Dr. Kasım Kurt for XL measurements, and Prof. Bekir Özçelik for his valuable advice and helps

Luminescence characteristics of Al-and Ca-doped BeO obtained via a sol-gel method

BeO, BeO:Al1%, BeO:Ca1%, and BeO:Al1%,Ca0.1% ceramics were synthesized by the sol-gel method. The X-ray luminescence was studied, and broad emission peaks located at 230 nm (~5.4 eV) and 300 nm (~4.1 eV) were observed. We investigated thermoluminescence peaks contributing to optically stimulated luminescence (OSL) signals for the ceramics. The thermal quenching of the OSL signals was evaluated, and the quenching energies were estimated as between approximately 0.5 eV and approximately 0.7 eV. To check the feasibility for dosimetry purposes, the dose response, reusability, and dark storage fading of the OSL signals were investigated. The dose response was observed to be linear between 0.1 and 100 Gy. The minimum detectable doses of BeO, BeO:Al1%, BeO:Ca1%, and BeO:Al1%,Ca0.1% were estimated as approximately 0.9 mGy, approximately 4 mGy, approximately 0.5 mGy, and approximately 0.5 mGy, respectively. Very good reusability was observed over ten cycles, with a maximum deviation of 2%. The results obtained from BeO:Al1%,Ca0.1% could be useful for OSL dosimetry, particularly in medical applications. © 2019 Elsevier LtdFDK-2018-10190This research was sponsored by the Cukurova University Rectorate through the project FDK-2018-10190 . We gratefully acknowledge Cukurova University for financial support. We appreciate Prof. Enver Bulur for valuable discussions and comments and Prof. Kasım Kurt for XL measurements

Characterization and some fundamental features of Optically Stimulated Luminescence measurements of silver activated lithium tetraborate

A new lithium tetraborate (Li2B4O7 or abbreviated as LTB) material was produced by adding various concentrations of Ag impurities to allow better luminescent properties using the solution combustion synthesis (SCS) method. The formation of single phase LTB was confirmed using X-ray Diffraction (XRD) data and Scanning Electron Microscopy (SEM) analysis indicated the existence of a tetragonal crystalline domain. Two broad band emissions located at ~ 272 nm (near UV region) and 526 nm (green region) were observed from room temperature photoluminescence (PL) under 205 nm excitation The synthesized material consisted of polycrystalline LTB with 1 wt% Ag (abbreviated herein as LTB:Ag) exhibits considerable thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) which is several times more sensitive to beta radiation than the other concentrations attempted. It was determined that the OSL signal has been a collection of three component signals. A step-preheating procedure to investigate the depth of the trapping centers associated with the OSL signal was carried out. We suggest that the TL peak at 200 °C mainly contributes to the OSL signal. It was observed that the total OSL area shows a linear dose response for beta doses ranging from 1 to 100 Gy. The minimum detectable dose (MDD) value was found to be around 3 mGy using the total OSL area. Under optimum conditions (irradiation with beta-rays), the reproducibility of total OSL area was determined with a -3% deviation at the end of the 9th irradiation-blue light stimulation-readout cycle. The dark storage stability of the total OSL signals was investigated and fading of the total OSL area was found to be approximately 25% after one week. The trap depth corresponding to the OSL signal was found to be 0.99 eV and 0.94 eV using various heating rate and isothermal annealing methods, respectively. Finally, silver doped lithium tetraborate is shown to have promise as an optically stimulated luminescent dosimeter, particularly in medical and personal applications. © 2018 Elsevier B.V.FBA-2016-6000, FYL-2015-3944, FDK-2017-6833, FYL-2016-6065, FUA-2015-4300This research is sponsored by the Cukurova University Rectorate through the Projects FDK-2017-6833 , FUA-2015-4300 , FBA-2016-6000 , FYL-2016-6065 and FYL-2015-3944 . We gratefully acknowledge the financial support given by Cukurova University. We very much appreciate Prof. Dr. Gulfeza Kardas and Fatih Tezcan for analyzing spectroscopic measurements

Optically stimulated luminescence characteristics of BeO nanoparticles synthesized by sol-gel method

Optically Stimulated Luminescence (OSL) properties of the sol-gel synthesized nano-powders of Beryllium Oxide (BeO) were investigated. Luminescence properties of BeO nanoparticles are dependent on the crystal structure, particle size, and morphology and therefore strongly dependent on the way of synthesis, thus the preparation was modified to enhance the OSL signal from the material. Structural, thermal and morphological properties of BeO in nanopowder and pellet forms were studied using X-Ray Diffraction (XRD), Fourier Transform Infrared Microscopy (FTIR), Simultaneous Thermal Analysis STA (Thermo Gravimetric Analysis (TGA)/Differential Scanning Calorimetry (DSC)) and Scanning Electronic Microscopy (SEM) techniques. XRD and STA analysis suggested an enhancement in crystallinity and thermal stability of the BeO with increasing sintering temperature. OSL dosimetric properties of the pellets prepared by pressing the synthesized powders were investigated in detail. Thermal stability of the signal as determined with a pulse heating experiment has shown that the OSL signal was stable up to depleted at around 300 °C, suggesting the suitability for dosimetric purposes. Dose response of OSL signals was observed to be linear in the dose range 0.1–100 Gy. The minimum detectable dose limit was estimated at around 100 µGy. Replicated measurements of the samples irradiated with the same dose indicated a good repeatability. Fading properties of the OSL signals were also studied up to 1 month. OSL signals of BeO pellets were decreased by approximately 11% at the end of 7 days and by about 17% at the end of 30 days when compared with the first readout. © 2018North Atlantic Treaty Organization SfP-984649, SPS Çukurova Üniversitesi: FBA-2016-6000, FYL-2015-3944, FUA-2015-4300This project has been supported by NATO in the frame of the NATO Science for Peace and Security (SPS) Programme under the project number SfP-984649 and by Çukurova University under the project numbers FUA-2015-4300 , FBA-2016-6000 and FYL-2015-3944 . We would like to thank NATO and Çukurova University Rectorate for their support