PSI - Issue 28

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 28 (2020) 971–977

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of MedFract1 organizers Keywords: Radiation detectors; Single Crystals; CdWO 4 , CaF 2 :Eu, Temperature dependence Abstract Scintillators are radiati n conv rters applied in medical imaging detectors, in applic tions at harsh environ ents, including in geophysical detectors for d ep geology borehol s, on-d structive testing (NDT) in ga and oil facilities, space, marine xplo ion, etc. In this study th luminescence efficiency depe dence of single-crystal scintillators was examined with increasing temperature. Cadmium ung tate (CdWO 4 ) was examined against calcium fl oride doped w th europium (CaF 2 :Eu). The di ensi ns of th sing e crystals' samples were 10x10x10 mm 3 and wer irrad ated using X-ray radiographic exposures (90 kVp, 63mAs) to measure the light output wi h temperature (22 to 128 °C). The luminescence efficiency was found in both cases maximum at he lowest examined te perature (23.06 efficiency units-E.U for CdWO 4 and 22.01 E.U. for CaF 2 :Eu, at 22 °C-environmental). With increasing temperature, the luminescence efficiency constantly d creased for both crystals due to thermal qu nch ng (5.32 efficiency units for CdWO 4 and 4.43 for CaF 2 :Eu, at 128 °C). In the mid-rang (50-80 °C) CdWO 4 shows increased difference compared to CaF 2 :Eu. CdWO 4 has a higher density (7.9 g/cm 3 ) and luminescence signal than CaF 2 :Eu (3.18 g/cm 3 ), thus it is suitable, besides medical imaging, also for operation in harsh environments. © 2020 The Authors. Published by Elsevier B.V. This is an ope acces article under th CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) P er-review under responsibility of MedFract1 organizers Keywords: Radiation detectors; Single Crystals; CdWO 4 , CaF 2 :Eu, Temperature dependence 1st Virtual European Conference on Fracture Temperature Dependence of the Luminescence output of CdWO 4 Crystal. Comparison with CaF 2 :Eu George Saatsakis a , Dionysios Linardatos b , Konstantinos Ninos c , IoannisValais b , Nektarios Kalyvas b , Athanasios Bakas c , Ioannis Kandarakis b , George Fountos b , George Panayiotakis a and Christos Michail b,* a University of Patras, School of Medicine, Department of Medical Physics, GR-15310, Rion, Greece b University of West Attica, Department of Biomedical Sciences, Athens 12210, Greece c University of West Attica, Radiation Physics, Department of Biomedical Engineering, Materials Technology and Biomedical Imaging Laboratory, Athens 12210, Greece Abstract Scintillators are radiation converters applied in medical imaging detectors, in applications at harsh environments, including in geophysical detectors for deep geology boreholes, non-destructive testing (NDT) in gas and oil facilities, space, marine exploration, etc. In this study the luminescence efficiency dependence of single-crystal scintillators was examined with increasing temperature. Cadmium tungstate (CdWO 4 ) was examined against calcium fluoride doped with europium (CaF 2 :Eu). The dimensions of the single crystals' samples were 10x10x10 mm 3 and were irradiated using X-ray radiographic exposures (90 kVp, 63mAs) to measure the light output with temperature (22 to 128 °C). The luminescence efficiency was found in both cases maximum at the lowest examined temperature (23.06 efficiency units-E.U for CdWO 4 and 22.01 E.U. for CaF 2 :Eu, at 22 °C-environmental). With increasing temperature, the luminescence efficiency constantly decreased for both crystals due to thermal quenching (5.32 efficiency units for CdWO 4 and 4.43 for CaF 2 :Eu, at 128 °C). In the mid-range (50-80 °C) CdWO 4 shows increased differences compared to CaF 2 :Eu. CdWO 4 has a higher density (7.9 g/cm 3 ) and luminescence signal than CaF 2 :Eu (3.18 g/cm 3 ), thus it is suitable, besides medical imaging, also for operation in harsh environments. 1st Virtual European Conference on Fracture Temperature Dependence of the Luminescence output of CdWO 4 Crystal. Comparison with CaF 2 :Eu George Saatsakis a , Dionysios Linardatos b , Konstantinos Ninos c , IoannisValais b , Nektarios Kalyvas b , Athanasios Bakas c , Ioannis Kandarakis b , George Fountos b , George Panayiotakis a and Christos Michail b,* a University of Patras, School of Medicine, Department of Medical Physics, GR-15310, Rion, Greece b University of We t Attica, Department f Biomedical Sciences, Ath ns 12210, Greece c University of West Attica, Radiation Physics, Department of Biomedical Engineering, Materials Technology and Biomedical Imaging Laboratory, Athens 12210, Greece

* Corresponding author. Tel.: +30-210-538-5387. E-mail address: cmichail@uniwa.gr * Corresponding author. Tel.: +30-210-538-5387. E-mail address: cmichail@uniwa.gr

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an ope acces article under t CC BY-NC-ND license (http://creativecommons. rg/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.11.071