Grazing Incidence Small-Angle Neutron Scattering: Background Determination And Optimization For Soft Matter Samples

Featured ApplicationScattering contributions in a grazing incidence small-angle neutron scattering experiment come not only from the evanescent wave, but may also come from small-angle scattering of the transmitted beam. Simulations can be used to quantify this contribution. Optimization of the sample cell may reduce an additional background scattering from the cell.Grazing incidence small-angle neutron scattering (GISANS) provides access to interfacial properties, e.g., in soft matter on polymers adsorbed at a solid substrate. Simulations in the frame of the distorted wave Born approximation using the BornAgain software allow to understand and quantify the scattering pattern above and below the sample horizon, in reflection and transmission, respectively. The small-angle scattering from the interfacial layer, visible around the transmitted beam, which might contribute also on the side of the reflected beam, can be understood in this way and be included into the analysis. Background reduction by optimized sample cell design is supported by simulations, paving the way for an optimized GISANS cell.