Abstract

Silicon Photomultipliers (SiPMs) have emerged as the optimal alternative to traditional Photomultiplier Tubes (PMTs) in modern scintillation detectors due to their high photon detection efficiency and compact design. Nevertheless, the design and optimization of SiPM-based measurement systems continue to face significant challenges in simulation, stemming from complex non-linear response characteristics and the presence of correlated noise components. Current simulation models typically oscillate between two extremes: oversimplified architectures that lead to substantial inaccuracies, or highly detailed microcell-level models that impose excessive computational overhead. This study proposes a balanced solution by developing a high-performance hybrid model for an EJ-276 plastic scintillation detector coupled with an SiPM array within the Geant4 simulation framework. The core of this methodology lies in integrating the transfer function of the equivalent electronic circuit with the statistical characteristic parameters of the SiPM, such as dark count rate, saturation effects, and optical crosstalk. The geometric configuration is detailed to include the organic scintillation block, reflective layers, and the optical transmission medium. The reliability of the model was validated through direct comparison with experimental data obtained from a measurement system utilizing the AFBR-S4N44P163 SiPM array. The results demonstrate a high degree of correlation in kinetic characteristics: the model successfully reproduced the signal pulse shape with a rise time () of 24.64 ns and a decay time () of 174 ns. Furthermore, the model accurately reflects the characteristic multi-peak structure of optical crosstalk and the positions of Compton edges resulting from interactions with standard gamma-ray sources such as and . With its optimized computational efficiency, this model serves as a vital tool for the analysis, evaluation, and design of next-generation mixed-field radiation spectrometers, significantly reducing empirical testing time while maintaining the necessary physical accuracy.