Light output and response function of an NE-213 scintillator to neutrons up to 100 MeV

Abstract

Light output of the NE-213 organic scintillator to 22.6, 27.6 and 48.7 MeV protons were obtained by the analysis of recoil proton spectra by monoenergetic neutron injection into the scintillator. The neutrons were generated by the proton bombardment on a thin lithium target backed with a thick carbon beam stopper. The measured light outputs were slightly smaller than the extrapolation of other works. Birks' semiempirical formula was fitted to these measured data and our previous experimental data of 11.03, 9.01 and 8.05 MeV protons and the formula failed to fit them completely over this wide energy region. A Monte Carlo code to calculate response functions of an NE-213 scintillator was improved by, 1) using these measured light output data, 2) using new cross sections of ENDF/B-IV, O5S and Guerra's compiled data, and 3) replacing the evaporation model of the C(n, p), C(n, pn) and C(n, 2n) reactions with the two-body reaction model. Results of this revised Monte Carlo calculation generally agreed well with the measured response functions of other works. Response functions of a 7.62-cm-diameter by 7.62-cm-long NE-213 scintillator to neutrons of energies up to 100 MeV were calculated by this Monte Carlo code.