Simulation and Research of Organic Scintillator Detectors for Large-scale Experimental Facilities

Sumitted to PubDB: 2026-05-07

Category: Master Thesis

Tags: KLM

Principal Authors Zibing Bai
Date 2026-05-07
Belle II Number BELLE2-MTHESIS-2026-025
Abstract This thesis presents a systematic study of organic scintillator detector technology for high-energy physics experiments based on the Geant4 simulation framework. The research begins by establishing an accurate optical model of organic scintillator materials through simulating light propagation characteristics and surface treatment effects within the scintillator. On this foundation, the study systematically examines the influence of parameters such as optical fiber coupling methods and diameter on photon collection efficiency, and establishes a structure-performance relationship model by varying the geometric parameters of scintillator strips, providing common baseline data for subsequent research. The work focuses on two interconnected yet distinctive directions: on one hand, based on the geometric parameters of the GAZELLE detector in the Belle II experiment, a complete model of an organic scintillator far detector was constructed. Through precise simulation of $K^0_L$ particles and their decay products' propagation and interaction processes in the detector, the study systematically analyzes the quantitative impact of detection unit structural design and overall detector dimensions on detection efficiency and solid angle coverage. The results indicate that optimizing scintillator strip arrangement and detector geometry can significantly enhance the detection capability for long-lived particle decay events. On the other hand, in response to the specific requirements of the CEPC experiment, the research completed the design and comprehensive simulation of the muon detector, and achieved full integration of the detector in the CEPCSW software framework. The study adopted parameter separation and structural simplification strategies, effectively addressing the challenges of large-scale integrated simulation under different precision requirements, and successfully balanced simulation accuracy and computational efficiency by establishing a parameterized detector response model. By developing multiple detector simulations centered around organic scintillator superlayers, we have formed a complete technical chain from material properties to detector systems, providing systematic technical support and methodological reference for detector design and optimization in high-energy physics experiments. The research results have been successfully applied to relevant work in the CEPC experiment and lay a foundation for future detector development in similar large-scale physics experiments.
Institute Nankai

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