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http://dx.doi.org/10.3807/JOSK.2014.18.3.256

A TiO2-Coated Reflective Layer Enhances the Sensitivity of a CsI:Tl Scintillator for X-ray Imaging Sensors  

Kim, Youngju (Iksan Radiation Imaging Technology Center)
Kim, Byoungwook (Iksan Radiation Imaging Technology Center)
Kwon, Youngman (Iksan Radiation Imaging Technology Center)
Kim, Jongyul (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology)
Kim, MyungSoo (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology)
Cho, Gyuseong (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology)
Jun, Hong Young (BK21plus Program and Department of Smart Life-Care Convergence, Wonkwang University)
Thap, Tharoeun (BK21plus Program and Department of Smart Life-Care Convergence, Wonkwang University)
Lee, Jinseok (BK21plus Program and Department of Smart Life-Care Convergence, Wonkwang University)
Yoon, Kwon-Ha (BK21plus Program and Department of Smart Life-Care Convergence, Wonkwang University)
Publication Information
Journal of the Optical Society of Korea / v.18, no.3, 2014 , pp. 256-260 More about this Journal
Abstract
Columnar-structured cesium iodide (CsI) scintillators doped with thallium (Tl) are frequently used as x-ray converters in medical and industrial imaging. In this study we investigated the imaging characteristics of CsI:Tl films with various reflective layers-aluminum (Al), chromium (Cr), and titanium dioxide ($TiO_2$) powder-coated on glass substrates. We used two effusion-cell sources in a thermal evaporator system to fabricate CsI:Tl films on substrates. The scintillators were observed via scanning electron microscopy (SEM), and scintillation characteristics were evaluated on the basis of the emission spectrum, light output, light response to x-ray dose, modulation transfer function (MTF), and x-ray images. Compared to control films without a reflective layer, CsI:Tl films with reflective layers showed better sensitivity and light collection efficiency, and the film with a $TiO_2$ reflective layer showed the best properties.
Keywords
CsI(Tl) scintillator; Light output; MTF; X-ray imaging detector;
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