ANSTO operates one neutron reflectometer (Platypus) and an X-ray reflectometer at the OPAL Reactor. But Platypus is heavily oversubscribed, and a second neutron reflectometer has long been needed.
In order to fill this need, ANSTO has successfully negotiated the transfer of the BioRef reflectometer from the BER-II Research Reactor at the Helmholtz-Zentrum Berlin. The transfer should take effect in 2016, and BioRef will be installed at the end of the CG2B guide, within OPAL’s Neutron Guide Hall. It is anticipated that user operations will commence in 2018.
Both Spatz and Platypus are time-of-flight reflectometers, each with four disc choppers to pulse the incident beam and define the wavelength resolution. Both instruments have full polarisation-analysis capability and have similar position-sensitive detectors. But while PLATYPUS operates in a vertical scattering plane and is well suited for studies of free air-liquid surfaces, which are necessarily horizontal, Spatz operates in the horizontal scattering plane geometry, with reflection from a vertical surface. This has some advantages for solid-air, buried solid-solid and solid-liquid interfaces.
In addition, the detector can be swung to much larger angles allowing measurement of diffraction from multilayers and lamellar stacks. Finally Spatz's geometry allows use of a much wider range of our sample-environment suite, including our 12-T cryomagnet and dilution insert.
The instrument comes with a built-in infra-red spectrometer, and cells that can handle simultaneous neutron reflectometry and infra-red spectroscopy.