Studying the response of a plastic scintillator to gamma rays using the Geant4 Monte Carlo code

• The energy distribution of optical photons in NE-102 scintillator was obtained.
• The pulse height of NE-102 for Cs-137 and Co-60 gamma ray source was calculated.
• The energy distribution and pulse height are consistent with the experimental data.
• Three models of the TiO2 surface treatment for NE-102 were investigated using the model.
• The time and spatial distribution were calculated using the model.

To determine the gamma ray response function of an NE-102 scintillator and to investigate the gamma spectra due to the transport of optical photons, we simulated an NE-102 scintillator using Geant4 code. The results of the simulation were compared with experimental data. Good consistency between the simulation and data was observed. In addition, the time and spatial distributions, along with the energy distribution and surface treatments of scintillation detectors, were calculated. This simulation makes us capable of optimizing the photomultiplier tube (or photodiodes) position to yield the best coupling to the detector.