Development of CdWO4-polystyrene scintillator composites for X-ray detection in imaging systems

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2022-02, Vol.1025, Article 166196
• Main Authors: Novais, S.M.V., Monteiro, T.J., Andrade, A.B., Gomes, M.A., Dias, C.S.B., Valerio, M.E.G., Macedo, Z.S.
• Format: Article
• Language: English
• Subjects: CdWO4; Composites; Polystyrene; X-ray imaging
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2021.166196

Scintillator screens have been used on multiple devices for X-ray tomography, being responsible for conversion of the X-ray beam into visible light that is then focused to form an image. In this context, CdWO4-polystyrene composite films were tested as detector screens at the Imaging Beamline of the Brazilian Synchrotron Light Laboratory. Samples with varied thickness (150μm, 300μm and 600μm) and CdWO4 load (10% and 40%) were characterized as a microtomography image screen. The performance of the composites as radiation sensors demonstrates the feasibility of using CdWO 4-PS scintillator for digital imaging applications. Spatial inhomogeneities of the composites were corrected by a digital flat image, thus allowing successful acquisition of absorption coefficients of the projected reference. Photoluminescence emission spectra provided understanding of the role of CdWO4 particles dispersion, which was optimized in order to reduce artifacts related to light scattering. In addition, spatial resolution of images acquired with CdWO4-PS was demonstrated to be improved with the higher scintillator concentrations and the smaller screen thickness.