Study of n-γ discrimination in low energy range (above 40 keVee) by charge comparison method with a BC501A liquid scintillation detector

A VME-based experiment system for n- gamma discrimination using the charge comparison method was established. A data acquisition program for controlling the programmable modules and processing data online via VME64X bus was developed through the use of LabVIEW. The two-dimensional (2D) scatter plots of the charge in the slow component vs. the total charge from super(241) Am-Be and super(252) Cf neutron sources are presented. The 2D scatter plots of the energy vs. the ratio of the charge in the slow component to the total charge of the pulses are also presented. The quality of n- gamma discrimination was checked by the figure-of-merit, and the results showed good performance of n- gamma discrimination at the low energy range. Neutrons and gamma -rays were separated above 50 keVee (electron-equivalent energy). The quality of n- gamma discrimination has been improved compared with others' results at five energies (150, 250, 350, 450, 550 keVee).