Forward scattering of 4·75 }5 neutrons in hydrogenous liquids

Small-angle scattering measurements from protonated polystyrene (PSH) and mixtures of deuterated and protonated toluene (C₇D₈ and C₇H₈) are presented. The data are compared with the simple `quasi-isotropic' Vineyard model, corrected for third- and higher-order multiple scattering by Monte Carlo methods. This model agrees surprisingly well with all protonated samples over the total thickness range considered. The empirical Jacrot g factor in the expression I(Q) = K(1 − T)g(λ)/4π works well over a more limited thickness range. The effective differential cross section can be calculated using Melkonian total cross sections, and this gives an absolute scattered intensity which is 9% lower than a calibration performed at Oak Ridge National Laboratory. Scattering from oversize samples must be back shielded. The model requires an anisotropic kernel to predict D/H toluene mixtures.