A Monte Carlo study of the effect of neutron scattering in a fast neutron radiography facility

Monte Carlo random sampling methods offer a powerful tool for the investigation of how neutron scattering can affect image formation in a fast neutron radiography facility, A laboratory developed for accelerator based fast neutron radiography contains various apparatus which may scatter neutrons. These include vacuum pumps, the accelerator tube, target used for generating the fast neutrons and the laboratory walls and ceiling composed of high density concrete bricks used to shield the outside environment from high energy neutrons. The Monte Carlo package MCNP-4A has been used to investigate the effect of scattering on image formation for a particular neutron source and geometry. In this study the known variation of neutron source strength and energy spectrum as a function of scattering angle has been included in the modelling process in order to produce an accurate assessment of the effect of scattered neutrons in any fast neutron radiography facility. (C) 1998 Elsevier Science B.V.