Neutron and Gamma-Ray Spectra from a Variety of Materials Bombarded with 14-MeV Neutrons

Characterizations of BC501A and BC537 liquid scintillator detectors

Two 2″×2″ liquid scintillator detectors BC537 and BC501A have been characterized for their responses and efficiencies to γ-ray detection. Light output resolution and response functions were derived by least-squares minimization of a simulated response function, fitted to experimental data. The γ-ray response matrix and detection efficiency were simulated with Monte Carlo (MC) methods and validated. For photon energies below 2.4 MeVee, the resolution, as well as the efficiency, of BC501A is better than BC537 scintillator. The situation is reversed when the energy is higher than 2.4 MeVee. BC537 has higher γ-ray detection efficiency than BC501A if the impinging photon energy is more than 2 MeV due to different ratios of C to H/D atoms.

Measurements and calculations of neutron spectra modified by iron slabs bombarded by neutrons with energies up to 14 MeV

Neutron spectra behind iron slabs of different thicknesses have been measured in the energy range from 1.6 to 14 MeV using a proton recoil spectrometer and 2H(d, n)3He and 9Be(d, n)10B neutron sources. The measured results have been compared with the predicted ones using the three dimensional Monte Carlo code MCNP 4A and pointwise cross sections from the ENDF/B-IV and ENDF/B-VI data files. The results show that the ENDF/B-IV calculations are in better agreement with the experiment than those obtained by using the ENDF/B-VI cross section data.