Spin-echo SANS grating standard measurement and analysis.

As part of the ongoing development and standardisation of SESANS instrumentation and data analysis methods the community is continuing to explore new calibration standards. The acquisition of 2 new bespoke silicon gratings will allow more robust calibration of Larmor at shorter spin-echo lengths and the development of more robust models for the observed scattering. The data will then be compared with subsequent measurements carried out at TU-Delft. In addition, the possibility of rotating the gratings to reduce the effective period will be explored as a method of further increasing the accuracy of the calibration at very short spin-echo lengths comparable with those observed in (V)SANS. It is likely that a new model will be required to accurately describe this data. This will be investigated by comparison with existing descriptions based on the phase object approximation and dynamical theory.