Design and performance of the variable-wavelength Bonse–Hart ultra-small-angle neutron scattering diffractometer KOOKABURRA at ANSTO

Abstract

The double‐crystal ultra‐small‐angle neutron scattering (USANS) diffractometer KOOKABURRA at ANSTO was made available for user experiments in 2014. KOOKABURRA allows the characterization of microstructures covering length scales in the range of 0.1–10 µm. Use of the first‐ and second‐order reflections coming off a doubly curved highly oriented mosaic pyrolytic graphite premonochromator at a fixed Bragg angle, in conjunction with two interchangeable pairs of Si(111) and Si(311) quintuple‐reflection channel‐cut crystals, permits operation of the instrument at two individual wavelengths, 4.74 and 2.37 Å. This unique feature among reactor‐based USANS instruments allows optimal accommodation of a broad range of samples, both weakly and strongly scattering, in one sample setup. The versatility and capabilities of KOOKABURRA have already resulted in a number of research papers, clearly demonstrating that this instrument has a major impact in the field of large‐scale structure determination.

Structure Analysis of Solid Lipid Nanoparticles for Drug Delivery: A Combined USANS/SANS Study

“…The USANS data were reduced with an empty Kookaburra cell data as background using Python scripts running in Gumtree based on the standard procedure and converted to an absolute scale. The reduced slit‐smeared data were de‐smeared using Lake's iterative technique, as implemented in the NIST data reduction macros and subsequently merged with the SANS data. De‐smearing the USANS data made it easier to compare with the SANS data.…”

Multi-scale assembly of hydrogels formed by highly branched arabinoxylans from Plantago ovata seed mucilage studied by USANS/SANS and rheology

“…Ultra-small angle neutron scattering (USANS) experiments were performed on the same samples studied with SANS, using the KOOKABURRA instrument at the OPAL reactor (Rehm, Brûlé, Freund & Kennedy, 2013;Rehm, Campo, Brûlé, Darmann, Bartsch & Berry, 2018). All samples were loaded in the demountable KOOKABURRA sample cells with the path lengths of 1 mm and the cross-section of 50 x 50 mm.…”

H2O/D2O Contrast Variation for Ultra-Small-Angle Neutron Scattering to Minimize Multiple Scattering Effects of Colloidal Particle Suspensions

“…USANS experiments were performed on the Kookaburra beamline on the cold-neutron guide CG3 at the Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation [31,32], with a monochromatic wavelength of 4.74 Å. Kookaburra is based on the Bonse-Hart method [33] and utilizes two identical, multi-bounce, channel-cut, perfect Si single crystals labelled 'monochromator' and 'analyzer' (arranged in non-dispersive or parallel geometry) in Bragg reflection, see Figure 1. When the monochromator and analyzer crystals are aligned (analyzer deviation angle θ = 0 • , i.e., the analyzer crystal is in the 'peak position'), an incident neutron beam is totally reflected into the main detector.…”