Multiple scattering of neutrons in liquid methane

Abstract

Multiple scattering effects in cold neutron scattering by hydrogeneous liquids in an infinite flat sample are investigated. The intensity of twice scattered neutrons is calculated with no restrictions on angular dependence or energy transfer. Using a dynamical model for liquid methane numerical results are obtained. In the inelastic region, the intensity ratio of secondary to primary scattering is found to vary from about 0.50 to 0.30 as the scattering angle is increased from 30 degrees to 90 degrees , for a specimen thickness of 0.1 cm. Explicit multiple scattering corrections are made for the Trombay time of flight spectra. As a result, the agreement between experiment and theoretical cross section is improved significantly.