General formula for determination of cross-section from measured SANS intensities

Abstract

A detailed derivation of the formula connecting measured SANS intensity with the smeared cross‐section (raw‐data treatment) is presented. The derivation is carried out considering also a possible high probability of the coherent small‐angle scattering. The information content of the so‐called transmission measurement is analyzed. The individual effects which contribute to the primary‐beam attenuation as well as the different modes of the transmission measurement are described. Multiple scattering contribution to the excess of the forward scattering of the water calibration standard is discussed.

Everything SAXS: small-angle scattering pattern collection and correction

“…Correcting for multiple scattering is generally a complex, iterative procedure where the multiple scattering smearing profile is estimated and removed from the data [114]. It becomes even more complicated for samples with direction-dependent sample thicknesses and hence different multiple scattering probabilities [12,174]. One avenue for simplifying the correction and estimation is by approximation of the multiple scattering effect as mainly consisting of double scattering [24,60,11].…”

Bonnes pratiques de la diffusion de neutrons aux petits angles

“…En toute rigueur et dans le cas de l'eau par exemple, deux effets concourent à sa déformation [6]. 1. la diffusion inélastique est très importante dans le cas de l'eau car la masse d'un proton est pratiquement identique à celle d'un neutron.…”

Evaluation procedure for anisotropic SANS

“…The new program version extends the advantages mentioned in . The raw-data evaluation part (Strunz, Šaroun, Keiderling, Wiedenmann & Przenioslo, 2000) allows to fit directly to the measured data. The possibility to perform 3D reciprocal-space fitting increases the amount of information which can be obtained for anisotropic arrangement of particles because some effects are invisible under certain sample orientations while they can be detected for others.…”

“…1). All usual corrections are taken into account; some less known ones are included as well (Strunz, Šaroun, Keiderling, Wiedenmann & Przenioslo, 2000). In certain cases, the precise raw-data treatment can not be done without the knowledge of the total SANS probability p cS .…”