Experimental corrections in neutron diffraction of ambient water using H/D isotopic substitution

Abstract

We report on the procedure to treat neutron diffraction data, in order to obtain the differential cross sections, a step that is essential in the analysis of structural information for liquids and amorphous materials. The treatment is applied to new measurements that have been made on the D4C diffractometer for eight different isotopic compositions of H2O/D2O mixtures at ambient temperature. The procedure is based on Monte Carlo simulations to perform multiple scattering, attenuation and detector efficiency corrections, applied iteratively. The normalization process allows the direct comparison of measured data from different samples, and requires the knowledge of the total cross-section at the incident neutron energy. They high contrast between the cross sections (coherent and incoherent) for heavy and light water allows to test the procedure under very different conditions of multiple scattering effects.