Ultra-Small-Angle X-ray Scattering Facility

X-ray science division, beamline 9ID-C


APS list of all USAXS publications:

View USAXS Publications

if your publication is NOT in this list (and should be), then send a copy to staff so it can be added, please. 


When you use data from this instrument, you are required to acknowledge APS use and cite appropriate instrument manuscripts in a publication. Standard APS acknowledgement must be included in your publication, poster, thesis, etc. For proper citations, please choose amongst these references:

For USAXS instrument use:

Ilavsky, J., P. R. Jemian, et al. (2009). "Ultra-small-angle X-ray scattering at the Advanced Photon Source." Journal Of Applied Crystallography 42(3): 469-479.

The design and operation of a versatile ultra-small-angle X-ray scattering (USAXS) instrument at the Advanced Photon Source (APS) at Argonne National Laboratory are presented. The instrument is optimized for the high brilliance and low emittance of an APS undulator source. It has angular and energy resolutions of the order of 10-4, accurate and repeatable X-ray energy tunability over its operational energy range from 8 to 18 keV, and a dynamic intensity range of 108 to 109, depending on the configuration. It further offers quantitative primary calibration of X-ray scattering cross sections, a scattering vector range from 0.0001 to 1 A-1, and stability and reliability over extended running periods. Its operational configurations include one-dimensional collimated (slit-smeared) USAXS, two-dimensional collimated USAXS and USAXS imaging. A robust data reduction and data analysis package, which was developed in parallel with the instrument, is available and supported at the APS.

If you have used 440 geometry:

Ilavsky, J., A. J. Allen, et al. (2012). "High-energy ultra-small-angle X-ray scattering instrument at the Advanced Photon Source." Journal Of Applied Crystallography 45(6): 1318-1320.

This paper reports recent tests performed on the Bonse-Hart-type ultra-small-angle X-ray scattering (USAXS) instrument at the Advanced Photon Source with higher-order reflection optics - Si(440) instead of Si(220) - and with X-ray energies greater than 20 keV. The results obtained demonstrate the feasibility of high-energy operation with narrower crystal reflectivity curves, which provides access to a scattering q range from ~2 x 10-5 to 1.8 A-1 and up to 12 decades in the associated sample-dependent scattering intensity range. The corresponding size range of the scattering features spans about five decades - from less than 10 A to ~15 microm. These tests have indicated that mechanical upgrades are required to ensure the alignment capability and operational stability of this instrument for general user operations because of the tighter angular-resolution constraints of the higher-order crystal optics.

Optionally we suggest also cite latest update:

Ilavsky, J., F. Zhang, et al. (2013). "Ultra-Small-Angle X-ray Scattering Instrument at the Advanced Photon Source: History, Recent Development, and Current Status." Metallurgical and Materials Transactions A 44(1): 68-76.

The 25-year history and development of an ultra-small-angle X-ray scattering (USAXS) instrument dedicated to serving materials research is presented and discussed. The instrument's successful track record is attributed to three factors. The first, and surely the most important, is that all development has been driven by scientific research directions and opportunities. Second, the USAXS instrument is a core capability rather than an add-on facility, with measurement capability from micrometers to nanometers, which is precisely the size range where microstructures determine physical properties. The third is that the instrument's range of capabilities has continually expanded, now including 2D collimation, imaging, and dynamics. And finally, USAXS has enjoyed the benefit of a management structure that has consistently appreciated the unique experimental measurement capabilities that USAXS delivers.

For data reduction from SAXS/WAXS:

Ilavsky, J. (2012). "Nika: software for two-dimensional data reduction." Journal Of Applied Crystallography 45(2): 324-328.

Nika is an Igor Pro-based package for correction, calibration and reduction of two-dimensional area-detector data into one-dimensional data (`lineouts'). It is free (although the user needs a paid license for Igor Pro), open source and highly flexible. While typically used for small-angle X-ray scattering (SAXS) data, it can also be used for grazing-incidence SAXS data, wide-angle diffraction data and even small-angle neutron scattering data. It has been widely available to the user community since about 2005, and it is currently used at the SAXS instruments of selected large-scale facilities as their main data reduction package. It is, however, also suitable for desktop instruments when the manufacturer's software is not available or appropriate. Since it is distributed as source code, it can be scrutinized, verified and modified by users to suit their needs.

If you have used Irena package for data analysis:

Ilavsky, J. and P. R. Jemian (2009). "Irena: tool suite for modeling and analysis of small-angle scattering." Journal of Applied Crystallography 42: 347-353.

Irena, a tool suite for analysis of both X-ray and neutron small-angle scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit small-angle scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye-Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and small-angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for small-angle scattering data, and a neutron and X-ray scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.