Testing neutron scattering on plastic scintillator observables to simulation

Plastic scintillators are widely used in nuclear physics experiments to detect neutrons. The MoNA collaboration uses them to measure neutrons from the decay of neutron-rich nuclei. These studies rely on simulations to interpret results; thus, it is essential to test the accuracy of simulating neutron scattering in plastic scintillators. Two Monte Carlo based simulation models were tested. The default package in GEANT-4 uses a cascade-based approach to simulate neutron scattering. Alternatively, a separate package called MENATE_R uses a cross section-based approach to simulate the neutron interaction based on measured inelastic reactions. An experiment was conducted at the Los Alamos Neutron Science Center with an array of plastic scintillators optimized to measure neutron scattering angles and energies. Neutrons were delivered with energies ranging from 20-400 MeV. At low energies, simulation agrees with data fairly well. At higher energies, agreement becomes worse. The shape of the kinetic energy distributions relies heavily on the energies of scattered protons from the scintillators. Discrepancies between the experimental and simulated data points to improvements needed in GEANT-4 and MENATE_R simulation packages in simulating neutron scattering from plastic scintillators.