Experimental benchmarking of large-scale PVT scintillator Geant4 simulations for performance prediction and design optimisation.

Plastic scintillators offer a low-cost radiation detection medium which is readily scalable to form large area detections systems. The benefit of increased detection efficiency gained from scaling such scintillators must be balanced against a decrease in light collection efficiency and degradation in the temporal response. Increasing the number, or area, of photo-sensors coupled to a scintillator improves total light collection efficiency however this increases cost while issues with the temporal response may remain. This paper describes the experimental benchmarking of a Geant4 Monte Carlo model used to predict the performance of a large ‘very fast timing’ (1.3 ns) polyvinyl-toluene scintillator coupled with a single photomultiplier tube. With the use of a highly collimated source, the efficiency and temporal response over the surface of the detector has been experimentally characterised and presented is a comparison between the Geant4 modelling and experimental results. The model will be used in the future for performance prediction and design optimisation of large-scale detection systems.