Monte Carlo simulations of the production of neutrons at iThemba LABS

Quasi-monoenergetic high-energy neutron standards above 20 MeV

“…This systematic method was extended to the energy region of 50 MeV to 200 MeV [87]. The FLUKA code was used to reproduce whole quasi-monoenergetic spectra [59]. Evaluated nuclear data were developed for the 7 Li(p, n) reaction for incident protons with energies up to 150 MeV which can be used in simulations with the MCNPX code [88].…”

“…These contributions could be subtracted by performing background measurements outside the well-collimated beam but should be kept as low as possible for measurements with small uncertainties, which could be especially important in calibrating detectors highly sensitive to low-energy neutrons. A Monte Carlo study to reduce the background is in progress [59].…”

“…To investigate the source of the background of moderated neutrons a rem counter was used to measure the ambient dose equivalent at various positions [58]. Background neutrons were also characterized by Monte Carlo simulations [59]. These approaches not only help reveal the sources of background neutrons but also help reduce background neutrons by indicating how best to apply preventive measures such as the addition of shielding materials.…”