Refractive Index Measurements of Organic Scintillators for Particle Transport Simulations

Organic scintillators are widely used in radiation detection and particle transport experiments, where accurate modeling of their optical properties is critical for simulation fidelity. In this work, we present a novel approach for measuring the index of refraction (RI) of six different organic scintillators using the lateral displacement of laser light as it passes through each sample. This method enables direct, wavelength-dependent determination of refractive indices, which can be incorporated into Geant4 particle transport models to improve agreement between simulation and experiment. Our results provide the first systematic set of RI measurements for these scintillators over multiple wavelengths, offering novel data for the community and a practical technique for optical characterization that is expected to enhance the accuracy of radiation detector modeling.