The dependence of neutron/gamma discrimination efficiency on demenstion of EJ-301 scintilator

This paper presents the results of research on the application of the Monte Carlo simulation method to investigate the dependence of neutron detection efficiency and neutron/gamma pulse discrimination capabilities on the size of a detector using the EJ-301 scintillator, supporting the design and development of neutron detectors. We constructed and evaluated eight cylindrical detector models with varying lengths and diameters using the Geant4 toolkit. The simulated detector models consist of a scintillator coupled with a light guide and a photomultiplier tube (PMT). The simulated pulse signals obtained from each model were analyzed to assess neutron/gamma discrimination using the digital charge integration (DCI) method, and neutron detection efficiency was determined at various energy thresholds. The neutron/gamma discrimination results were evaluated based on the Figure of Merit (FoM). The results showed that both neutron/gamma discrimination and neutron detection efficiency are significantly dependent on the detector size, particularly the variations in length and diameter. These findings are crucial for optimizing the design of neutron detectors using organic scintillators like EJ-301 or similar materials, aiming to enhance neutron/gamma discrimination and neutron detection efficiency.