KWS-3

KWS-3

KWS-3 is a very small angle neutron scattering (VSANS) instrument running on the focussing mirror principle. KWS-3 is designed to bridge the gap between Bonse-Hart and pinhole cameras. Owing to its extended Q range, optimized flux, and good wavelength resolution, KWS-3 has shown good performance and has become scientifically productive to the user community.The principle of this instrument is a one-to-one image of an entrance aperture onto a 2D position sensitive detector by neutron reflection from a double-focussing toroidal mirror.

The instrument’s standard configuration with a 9.5 m sample-to-detector distance allows performing scattering experiments with a wave vector transfer resolution between 4.0·10^-5 and 2.5·10^-3 Å^-1, bridging a gap between Bonse-Hart and pinhole cameras. A second sample position at 1.3 m sample-to-detector distance extends the Q-range of the instrument to 2.0·10^-2 Å^-1 and reaches more than one-decade overlapping with the classical pinhole SANS instruments. Another “mobile” sample position can be installed to adept sophisticated sample environment between 8 and 2 m sample-to-detector distance according to the requested instrumental resolution.

The instrument covers the Q range of small angle light scattering instruments. Especially when samples are turbid due to multiple light scattering, V-SANS gives access to the structural investigation. Thus, the samples do not need to be diluted. The contrast variation method allows for highlighting of particular components.
Small-angle scattering is used for the analysis of structures with sizes just above the atomic scale, between 1 and about 100 nm, which can not be assessed or sufficiently characterised by microscopic techniques. KWS-3 is an important instrument extending the accessible range of scattering angles to very small angles with a superior neutron flux when compared to a conventional instrumental set up with pinhole geometry. Thus, the length scale that can be analysed is extended beyond 10 μm for numerous materials from physics, chemistry, materials science, and life science, such as alloys, diluted chemical solutions, and membrane systems.