Diffraction gratings as small-angle X-ray scattering calibration standards

It is shown that diffraction gratings can be used as accurate momentum-transfer calibration standards in small-angle X-ray scattering experiments. For demonstration purposes, a silicon diffraction grating with a period of 400 nm is used. The data exhibit 50 diffraction peaks evenly distributed in the momentum-transfer range q = 0.0-0.8 nm^-1, a regime that is not accessible using the traditional silver behenate standard.