S18 - Neutron interferometer
The perfect crystal neutron interferometer is a Mach-Zehnder type interferometer for thermal neutrons. The neutron beam is split into two beam paths which are separated macroscopically in the order of 5cm. The beams are recombined and their interference fringes are measured, revealing the quantum mechanical phase shift between the two beams.
S18 - USANS
Ultra Small Angle Neutron Scattering extends the range of SANS instruments (e.g. instrument D11) towards smaller scattering angles, smaller momentum transfers or larger structure sizes up to 30µm. Unlike the pinhole geometry of a SANS setup, the USANS setup is sensitive to scattering in only one (horizontal) direction.
Applications and examples
A vibration isolated optical bench provides support for two perfect silicon crystals. The first crystal, the monochromator, is located in a thermal beam line (H25) and directs the neutrons of the selected wave length onto the second crystal. The second crystal can be the interferometer or the USANS analyzer crystal. The crystals are in non-dispersive configuration, meaning that all neutrons reflected by the first crystal are accepted by the second.