TY - JOUR AU - Martini, Niki AU - Koukou, Vaia AU - Fountos, George AU - Valais, Ioannis AU - Kandarakis, Ioannis AU - Michail, Christos AU - Bakas, Athanasios AU - Lavdas, Eleftherios AU - Ninos, Konstantinos AU - Oikonomou, Georgia AU - Gogou, Lida AU - Panayiotakis, George PY - 2019/09/02 Y2 - 2024/03/19 TI - Imaging performance of a CaWO4/CMOS sensor JF - Frattura ed Integrità Strutturale JA - Fra&IntStrut VL - 13 IS - 50 SE - SI: Research activities of the Greek Society of Experimental Mechanics of Materi DO - 10.3221/IGF-ESIS.50.39 UR - https://www.fracturae.com/index.php/fis/article/view/2614 SP - 471-480 AB - <p>The aim of this study was to investigate the modulation transfer function (MTF) and the effective gain transfer function (eGTF) of a non-destruc­­tive testing (NDT)/industrial inspection complementary metal oxide semi­conductor (CMOS) sensor in conjunction with a thin calcium tungstate (CaWO<sub>4</sub>) screen. Thin screen samples, with dimensions of 2.7x3.6 cm<sup>2</sup> and thick­ness of 118.9 μm, estimated from scanning electron microscopy-SEM im­ages, were extracted from an Agfa Curix universal screen and coupled to the active area of an active pixel (APS) CMOS sensor. MTF was assessed using the slanted-edge method, following the IEC 62220-1-1:2015 method. MTF values were found high across the examined spatial frequency range. eGTF was found maximum when CaWO<sub>4 </sub>was combined with charge-coupled devices (CCD) of broadband anti-reflection (AR) coating (17.52 at 0 cycles/mm). The com­bi­nation of the thin CaWO<sub>4</sub> screen with the CMOS sensor provided very pro­mis­ing image resolution and adequate efficiency properties, thus could be also con­sidered for use in CMOS based X-ray imaging devices, for various applications.</p> ER -