A GEANT4-Based Simulation of Directional Neutron Detectors Using Liquid Scintillators and Boron Carbide Moderators

We present a simulation-based study of a compact directional neutron detector composed of liquid scintillator, Cesium Iodide, with boron carbide (B4C) moderation, and silicon photomultipliers (SiPMs). Using GEANT4, we explored multiple detector geometries and material configurations, finding neutron detection efficiencies ranging from approximately 10% to 30%. To evaluate directionality, spatial energy distributions were analyzed and used to train a machine learning classifier, which achieved 100% accuracy in identifying neutron source directions along four cardinal axes. The model remained effective for sources near detector edges, demonstrating robustness. These results establish the feasibility of the proposed detector for applications in nuclear safety, environmental monitoring, and scientific research applications, with future work focused on experimental validation.