Neutron spectrometry in a mixed field of neutrons and protons with a phoswich neutron detector Part I: response functions for photons and neutrons of the phoswich neutron detector

We have developed a phoswich neutron detector consisting of an NE213 liquid scintillator surrounded by an NE115 plastic scintillator to distinguish photon and neutron events in a charged-particle mixed field. To obtain the energy spectra by unfolding, the response functions to neutrons and photons were obtained by the experiment and calculation. The response functions to photons were measured with radionuclide sources, and were calculated with the EGS4-PRESTA code. The response functions to neutrons were measured with a white neutron source produced by the bombardment of 135MeV protons onto a Be+C target using a TOF method, and were calculated with the SCINFUL code, which we revised in order to calculate neutron response functions up to 135MeV. Based on these experimental and calculated results, response matrices for photons up to 20MeV and neutrons up to 132MeV could finally be obtained.