Response of a BaF_2 scintillation detector to quasi-monoenergetic fast neutrons in the range of 45 to 198 MeV

摘要

We have studied the neutron response of a scintillation detector consisting of a 14 cm long, hexagonal-shaped BaF_2-crystal with an inner diameter of 8.75 cm coupled to an EMI9821QB photomultiplier tube. The detector was exposed to calibrated quasi-monoenergetic neutron fields obtained from ~7Li(p,n)~7Be reactions. The measurements were performed at neutron energies of 45, 60, 96, 147 and 198 MeV as given by the energies of the incident protons. The experimental pulse-height spectra of the BaF_2-detector are compared with Monte Carlo simulations using the FLUKA code. The detection efficiency of the BaF_2-detector in the energy range of 45-198 MeV was determined as a function of the discriminator threshold and compared to the literature data. At neutron energies above 100 MeV the detection efficiency of the BaF_2-detector was found to be a factor of two higher than that of an NE213-detector of comparable size.