The multipurpose time-of-flight neutron reflectometer "Platypus" at Australia's OPAL reactor
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Date
2011-03-11
Journal Title
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Publisher
Elsevier Science BV
Abstract
In this manuscript we describe the major components of the Platypus time-of-flight neutron reflectometer at the 20 MW OPAL reactor in Sydney, Australia. Platypus is a multipurpose spectrometer for the characterisation of solid thin films, materials adsorbed at the solid-liquid interface and free-liquid surfaces. It also has the capacity to study magnetic thin films using spin-polarised neutrons. Platypus utilises a white neutron beam (lambda=2-20 angstrom) that is pulsed using boron-coated disc chopper pairs; thus providing the capacity to tailor the wavelength resolution of the pulses to suit the system under investigation. Supermirror optical components are used to focus, deflect or spin-polarise the broad bandwidth neutron beams, and typical incident spectra are presented for each configuration. A series of neutron reflectivity datasets are presented, indicating the quality and flexibility of this spectrometer. Minimum reflectivity values of <10(-7) are observed: while maximum thickness values of 325 nm have been measured for single-component films and 483 nm for a multilayer system. Off-specular measurements have also been made to investigate in-plane features as opposed to those normal to the sample surface. Finally, the first published studies conducted using the Platypus time-of-flight neutron reflectometer are presented. (C) 2011 Elsevier B.V. All rights reserved.
Description
Keywords
Cold neutrons, Thin films, Reflectivity, Spectrometers, Membranes, OPAL Reactor
Citation
James, M., Nelson, A., Holt, S.A., Saerbeck, T., Hamilton, W.A., Klose, F. (2011). The multipurpose time-of-flight neutron reflectometer "Platypus" at Australia's OPAL reactor. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 632(1), 112-123. doi:10.1016/j.nima.2010.12.075