Construction and calibration of the multi-neutron correlation spectrometer at Peking University

A Multi-Neutron Correlation Spectrometer (MuNCoS) composed of 80 detector modules was constructed at Peking University. A position resolution of less than 3 cm (FWHM) for a typical long scintillation module was obtained based on cosmic ray tests. A calibration method using an unstable nucleus beam of 11Be, together with the fragment identification by using a zero degree telescope, has been successfully developed. Neutron detection efficiencies of 15(1)% and 17(2)% were achieved for neutron energy intervals of 30-40 MeV and 40-60 MeV, respectively, and at a signal charge threshold of 4 MeVee. The experimentally determined neutron detection efficiencies agree well with the simulation based on the GEANT4 code.