Response of a BaF2 scintillation detector to quasi-monoenergetic fast neutrons in the range of 45 to 198Â MeV

We have studied the neutron response of a scintillation detector consisting of a 14 cm long, hexagonal-shaped BaF2-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 BaF2-detector are compared with Monte Carlo simulations using the FLUKA code. The detection efficiency of the BaF2-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 BaF2-detector was found to be a factor of two higher than that of an NE213-detector of comparable size.