An effective hydrogen scattering cross section for time-of-flight neutron experiments with simple organic molecules

Abstract

The wavelength dependence of the effective neutron cross section for hydrogen has been investigated by measuring the transmitted total scattering cross section in urea, β-alanine, tartaric acid and polyethylene over the energy range 3 meV to 10 eV. Under the assumption that carbon, nitrogen and oxygen atoms contribute a small and invariant amount to the measured total cross section, these data represent a direct measure of the wavelength dependence of the overall scattering contribution of the hydrogen atoms to the total cross section. These experimental data can be used to apply effective wavelength-dependent corrections to neutron scattering data of hydrogen-rich simple organic compounds.