Fast neutron response characterization of an EJ-276 plastic scintillator for use as a neutron monitor

Abstract

EJ-276 is a recent development in plastic scintillators that comes with improved pulse shape discrimination over its predecessor EJ-299-33. In this work, the neutron response functions, proton light output function, and detection efficiency of EJ-276 were measured using mono-energetic neutron reference fields at the national metrology laboratory, Physikalisch-Technische Bundesanstalt, in the neutron energy range 1.5–19 MeV. In particular, the proton light output in the range 14–19 MeV is presented for the first time. The optimization of Pulse Shape Discrimination has also been investigated using an 241Am-Be source and results are presented. Finally, we study how, using a shadow-cone method and time of flight method, we can discriminate scattered and other spurious neutrons from the mono-energetic beam. The characterized EJ-276 detector is to be used in the monitor of the neutron fields and gamma background at the new Neutron Irradiation Laboratory for Electronics facility at the Rutherford Appleton Laboratory.