Isotope effects in thermal neutron transmission and backscattering processes for epsilon-phase zirconium hydrides and deuterides

摘要

Distributions of hydrogen isotope concentrations in c-phase zirconium hydrides and deuterides (epsilon-ZrHx and epsilon-ZrDx: 1.8 < x < 2.0) were investigated by neutron radiography (NRG). The NRG images of the thermal neutron transmission and backscattering revealed hydrogen concentration dependence and isotope differences. The thermal neutron mass attenuation coefficients in relation to the hydrogen isotope concentrations were determined from the transmission NRG images. The results showed the isotope effects of the thermal neutron mass attenuation coefficients for epsilon-ZrHx to be about 6-9 times higher than those for epsilon-ZrDx. The neutron scattering processes for transmission and backscattering NRG images of epsilon-ZrHx and epsilon-ZrDx were also analyzed using a general Monte Carlo neutron-particle transport (MCNP) code. (C) 2008 Elsevier B.V. All rights reserved.