Simulation Validation of Neutron Interaction with SiPMs

The MoNA Collaboration is designing and constructing a Next-Generation Neutron Detector (NGn) to enhance position detection capabilities for fast-neutron detection in experiments conducted at the Facility for Rare Isotope Beams (FRIB). The new detector will incorporate silicon photomultipliers (SiPM) that convert photons into electrical signals. SiPMs are compact, cost-effective, and unaffected by magnetic fields, making them well-suited for neutrons in energy ranges of 100-200 MeV. A prototype detector consisting of a 24 x 24 x 2.5 cm³ plastic scintillator and SiPM chips arranged with different spacing was tested at Triangle Universities Nuclear Laboratory using an 8 MeV neutron beam. Many of the SiPM chips were assembled by undergraduate students. The experimental data taken using the neutron beam were analyzed and compared to results from a GEANT4-based simulation using ROOT. The detector assembly, SiPM construction process, and simulation and data comparisons will be presented.