Impact of Surface Coating Materials and Geometry on the Efficiency of Organic and Inorganic Scintillators: A GEANT4 Simulation Study

This study investigates the impact of various reflective coating materials on the photon counting efficiency of selected organic and inorganic scintillators using GEANT4 simulation toolkit. Reflective coatings, including titanium dioxide, TeflonTM tape and aluminum foil, were applied to both scintillator surfaces to analyse photon collection efficiency by counting optical photons. The simulations were conducted for gamma photon energies of 59 keV, 662 keV and 1173 keV representative of low, medium, and high-energy regimes. The results indicate that aluminum foil provides the highest photon collection efficiency for high-energy gamma photons, while teflon tape exhibits superior performance at lower energies. Multilayer coatings of titanium dioxide and teflon tape show incremental improvements in photon collection, whereas aluminum foil achieves high reflectivity with a single layer, making it a cost-effective and efficient solution. Furthermore, the efficiency enhancement is significantly more pronounced in organic scintillators. These findings provide valuable insights into the selection of optimal reflective coatings for different scintillator materials and radiation energy levels, contributing to the optimization of radiation detection systems used in medical imaging, nuclear physics, and high-energy particle experiments.