3D printing of composite reflectors for enhanced light collection in scintillation detectors

The present study deals with the fabrication of light-reflecting materials used in pixelated scintillator detectors. For the first time, the reflecting surfaces for pixels of different sizes (from 0.8 to 3.2 mm) were obtained via a low-cost DLP 3D printing technique. The material for the reflectors was the new composite of transparent ultraviolet light-cured resin and TiO₂ as a light-scattering filler. It was observed that TiO₂ showed better performance compare to other pigments such as BaSO₄, hBN or cubic zirconia. The object formation rate was about 1 cm per hour with the possibility to produce several parts simultaneously that simplifies the wrapping procedure. It was found that the regular grooves pattern of the fabricated parts (staircase effect) could increase a light collection from a scintillator. The reflective properties of such surfaces were comparable to conventional reflection coating (e.g., Teflon wrapping).