Double-Crystal SANS Diffractometer (MAUD)

(former DN2)

The double-crystal diffractometer MAUD is designed for the measurements of neutron small-angle scattering in the high Q-resolution range. In contrast to conventional double-crystal arrangements, the fully asymmetric diffraction geometry on the elastically bent Si analyzer is employed to transfer the angular distribution of the scattered neutrons to the spatial distribution and to analyze the whole scattering curve by a one-dimensional position sensitive detector. It reduces the exposition time per sample typically to 0.5-5 hours (depending on the Q-resolution and sample cross-section). The remote control of the curvatures of the monochromator and analyzer crystals makes possible to tune the instrument resolution easily in the dQ range from 10^-4 to 10^-3 Ă ^-1, according to the expected size of investigated inhomogeneities. An absolute calibra-tion of scattering cross-sections is possible by measuring the intensity of the direct beam (no calibration samples are required). The instrument operates in fully automatic mode, including sample exchange.