Developing a 2D position-sensitive detector utilizing the large plate plastic scintillator

This study introduces a novel position-sensitive detector based on plate-shaped plastic scintillator. The detector, consisting of a 50 × 5 × 50 cm plastic scintillator coupled to four photomultiplier tubes, was designed to pinpoint the 2D location of a 137 Cs γ-ray source. A mathematical model was developed to predict the source position based on the ratio of signals from the photomultiplier tubes. Additionally, a machine learning approach using a Multi-Layer Perceptron (MLP) was employed for more automated position prediction. Based on the obtained results, it was found that the mean absolute error for determining the 2D position of the source was 1.3 cm for the mathematical model and 0.5 cm for the trained MLP model. To validate this model, optical simulations were also conducted using the Geant4 Monte Carlo toolkit.