Kookaburra: the ultra-small-angle neutron scattering instrument at OPAL

The new double crystal ultra-small-angle neutron scattering instrument Kookaburra, currently under construction at the ANSTO OPAL reactor, will allow characterization of microstructures covering length scales in the range of 0.1 to 10 µm. Using the 002 and 004 reflections of a doubly curved mosaic highly oriented pyrolytic graphite premonochromator crystal at a fixed Bragg angle of 45° in conjunction with two pairs of Si(111) and Si(311) quintuple-reflection channel-cut crystals will allow operation of the instrument at two different wavelengths, thus optimally accommodating weakly and strongly scattering samples in one sample position. The versatility, the estimated neutron fluxes and the low background noise of Kookaburra suggest that this state-of-the-art instrument will have a major impact in the field of large-scale structure determination.