Comparison of pseudo reflectivity with the reflectivity from conventional reflectometry

Grazing incidence X-ray off-specular scattering (GIXOS) data and the reflectivity (XRR) from conventional reflectometry are measured on the same sample surfaces: pure water, and DSPC monolayer on water. Pseudo XRR is derived from the GIXOS data using the extended Capillary Wave Model, that taken into account the analysis of the bending modulus from the diffuse scattering data. Moreover, the pseudo XRR derivation has also used the same reflectometry slit settings, and taken into account the way how reflectometry background is subtracted. Both the water surface free of bending rigidity and the DSPC with 20kT bending modulus show excellent agreement between the pseudo XRR and the conventional XRR. These datasets enter the publication of the extended Capillary Wave Model that is under review on the 15th of July, 2025.