Geant4 Simulation of Neutron Beam Monitor in Gamma-Ray Total Absorption Facility

The relative detection efficiency of a lithium glass detector used as a neutron beam monitor in gamma-ray total absorption facility was simulated by Geant4. The neutron detection efficiency of the lithium glass detector was obtained between 10 keV and 1 MeV. Some factors affecting the efficiency were analyzed. The effect of the time delay caused by the elastic scattering upon TOF (time-of-flight) measurement, and the n-γ discrimination in different thickness lithium glass were discussed. The work will be helpful to understand better the neutron time of flight spectrum and energy spectrum from Li-glass detector which is used as a monitor of keV neutron source.