PSI - Issue 26

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 il l li t . i i t. tr t r l I t rit r i ( )

www.elsevier.com/locate/procedia . l i r. /l t / r i

ScienceDirect

Procedia Structural Integrity 26 (2020) 3–10

t

© 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 Abstract During the last decades, there is increasing interest in applications of scintillators at harsh environments (i.e., high temperatures or radiation fluxes), such as in geophysical detectors for deep geology boreholes, non-destructive testing (NDT) of pipelines in oil and gas industry, space and marine exploration, nuclear reactor monitoring, radiation chemistry, etc. To this aim, the current study is the first step towards the investigation of the luminescence efficiency dependence of single-crystal scintillators over wide temperature ranges. Calcium fluoride doped with europium (CaF 2 :Eu) was selected due to the fact that it has a high melting point at 1418°C and is also robust to mechanical and thermal shocks. The dimensions of the single -crystal sample were 10x10x10 mm 3 , and it was irradiated using typical X-ray radiographic exposures (90 kVp, 63mAs) in order to measure the light photon intensity dependence with temperature (22 to 128 °C). The luminescence efficiency was found maximum at th e lowest examined temperature (22.01 efficiency units- E.U. at 22 °C -environmental). With increasing temperature, the luminescence efficiency decreased almost exponentially due to thermal quenching (4.43 efficiency units- E.U. at 128 °C). © 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: Inorganic Scintillators; Single Crystals; Radiation detectors; CaF 2 :Eu, Temperature dependence i t l t , t i i i i t t i li ti i till t t i t i. ., i t t i ti l , i i l t t l l , t ti t ti i li i il i t , i l ti , l t it i , i ti i t , t . t i i , t t t i t i t t t t i ti ti t l i i i i l t l i till t i t t . l i l i it i : l t t t t t t it i lti i t t i l o t t i l t l . i i t i l t l l 3 , it i i t i t i l i i , i t t li t t i t it it t t t . l i i i i t t l t i t t . i i it . . t i t l . it i i t t , t l i i i l t ti ll t t l i . i i it . . t . t . li l i B.V. This is an o ti l t li tt :// ti . /li / / . / i i ilit t i : I r i i till t r ; i l r t l ; i ti t t r ; 2 : , r t r The 1 st Mediterranean Conference on Fracture and Structural Integrity, MedFract1 Luminescence efficiency of CaF 2 :Eu single crystals: Temperature dependence George Saatsakis a , Konstantinos Ninos b , Ioannis Valais c , Niki Martini c , Nektarios Kalyvas c , Charilaos Kantsos b , Athanasios Bakas b , Ioannis Kandarakis c , George Panayiotakis a , Christos Michail c, * 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 Th , a i it f t , l f i i , t t f i l i , - , i , b i it f t tti , t t f i i l i , t , c i it f t tti , i ti i , t t f i i l i i , t i l l i i l I i t , t ,

* Corresponding author. Tel.: +0030-210-5385387 E-mail address: cmichail@upatras.gr i t r. l.: - - - il : i il tr . r rr

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 MedFract1 organizers l i . . i i ti l t li tt :// ti . /li / / . / i i ilit t i - t . li

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 MedFract1 organizers 10.1016/j.prostr.2020.06.002