The ultra-small-angle x-ray scattering instrument on UNICAT at the APS

A new ultra-small-angle X-ray scattering (USAXS) instrument has been commissioned as part of the UNICAT facility on the 33-ID line at the Advanced Photon Source. The instrument offers continuously-tunable optics for anomalous USAXS, 1000 times the throughput of earlier USAXS instruments(1,2), high sensitivity and high resolution at low scattering vector, and a scattering vector range from below 0.00015 Angstrom(-1) to above 0.5 Angstrom(-1). Early results include USAXS from colloidal silica suspensions, and anomalous USAXS from rare- earth oxides in the presence of similarly-sized cavities in silicon nitride. The addition of side-reflection optics, in an optional configuration of this instrument, enables USAXS measurements of anisotropic as well as isotropic materials.