Simulation of the neutron response matrix of an EJ309 liquid scintillator

The neutron response matrix is the basis for measuring the neutron energy spectrum through unfolding the pulse height spectrum detected with a liquid scintillator. Based on the light output of the EJ309 liquid scintillator and the related reaction cross sections, a Monte Carlo code is developed to obtain the neutron response matrix. The effects of the related reactions, the contributions of different number of neutron interactions and the wall effect of the recoil proton are discussed. With the obtained neutron response matrix and the GRAVEL iterative unfolding method, the neutron energy spectra of the  252Cf and the  241AmBe neutron sources are measured, and the results are respectively compared with the theoretical prediction of the  252Cf neutron energy spectrum and the previous results of the  241AmBe neutron energy spectra.