Ultra-Small-Angle X-ray Scattering (USAXS/SAXS/WAXS)
Current situation :
Instrument is now in 20IDB, operational but undergoing further commissioning.
USAXS is NOT available through GU program, you will NOT find it listed.
USAXS will be operating in commissioning mode until APS-U shutdown in April 2023.
After APS-U shutdown USAXS will be in 12IDC.
USAXS experimental time is currently allocated by staff based on available capabilities, staff time, and needs of experiments. Contact staff (Jan Ilavsky, 630-252-0866) with requests for beamtime.
We accept mail-in experiments and, preferably, in person experiments compatible with available capabilities.
The USAXS/SAXS/WAXS facility offers world-unique capabilities to wide range of communities in physics, chemistry, materials science, polymers, food science, biology, and many others. Data are measured over about:
- 5 decades in sizes - from approximately 6 microns to less than 1 Angstrom
- Intensity range of up to 12 decades
- About 3-4 minutes data collection time.
This is achieved by combination of Bonse-Hart design USAXS with SAXS and WAXS devises. See some example data in graphics below on this page.
Data are collected sequentially using one or more of our devices.
USAXS use is required.
Typical USAXS beam size is 0.8 x 0.8 mm. Beam size is flexible between 1 x 1 mm to 0.2 x 0.2 mm. Smaller beam sizes require stronger scattering systems.
Standard SAXS/WAXS beam size is 0.8 x 0.2 mm and can be as small as 0.2 x 0.2 mm. Smaller beam sizes require longer exposure times.
Typical combined data collection time is ~3 minutes for USAXS/SAXS/WAXS
USAXS data collection time is 60 - 180 sec (typical ~ 90s),
SAXS & WAXS is 1 - 60 sec each (typical ~ 20 sec).
Want to see how USAXS operates? 3 min (166Mb) movie with data collection is here: USAXS_operations.mp4
Current instrument paper: Ilavsky, J., Zhang, F., et al. (2018). "Development of combined microstructure and structure characterization facility for in situ and operando studies at the Advanced Photon Source." Journal Of Applied Crystallography 51, 867-882. https://doi.org/10.1107/S160057671800643X
Access to our instrument under commissioning mode:
In person experiments - if compatible with available capabilities, scheduled by staff from commissioning time. Limitations will vary.
Mail in program: We make available about 2-3 days of beamtime per cycle to users, who have smaller sets of samples (typically less than 20 samples). Typical use is exploratory research (before applying for beamtime) or when project requires limited number of samples. No beamtime proposal is necessary and users cannot come for experiments to the APS. Samples will be handled by USAXS staff and reduced data will be sent back to users. For details see dedicated page.
Proprietary (industrial) research is available as part of GU program. Contact staff and APS users office, start here.
Examples of USAXS results for general public:
2020 APS Scientific highlight (Pickering Emulsions)
2021 APS Scientific highlight (Colloidal gels)
Typical parameters are below:
Standard USAXS configuration (Si 220 crystals, slit smeared) - default
- Energy range ............ 12 - 24 keV, typical 21keV
- Q range combined .... 8*10-5 to 6 [A-1]
- Q resolution USAXS .. 8*10-5 [A-1] in the USAXS range (up to ~0.1 [A-1])
- Size range comb........ 6 micron - 1 Angstrom
- Collection time comb.. 2 - 5 minutes
- Intensity range ........... up to 12 decades (depends on sample), desmeared
- SAXS Q range ........... ~ 0.03 to 1.3 [A-1]
- WAXS Q range .......... ~ 0.8 to 6 [A-1]
High resolution USAXS configuration (Si 440 crystals, slit smeared) - special & justified request only Energy ....................... 12 - 18 keV, 18keV typical Q range combined .... 3*10-5 to 6 [A-1] Q resolution USAXS... 3*10-5 [A-1] in the USAXS range (up to ~0.1 [A-1]) Size range comb........ 20 micron - 1 Angstrom Collection time comb.. 4 - 6 minutes Intensity range ........... up to 12 decades (depends on sample), desmeared SAXS Q range ........... ~ 0.03 to 1.3 [A-1] WAXS Q range .......... ~ 0.8 to 6 [A-1] 2D collimated USAXS (Si 220 crystals) - not available until after APS upgrade (~2025) Energy .................... 12 - 21 keV Q range .................. 8*10-5 [A-1] to 0.1 [A-1] Collection time ........ 4 - 6 minutes Intensity range ........ up to 8 decades (depends on sample) Q resolution ............ 3*10-5 [A-1] in the USAXS range (up to ~0.1 [A-1]) SAXS ....................... not available WAXS ...................... not available
USAXS Imaging - not available until after APS upgrade (~2025)
Graph of results and schematics:
Schematics of USAXS instrument. For illustration only, NOT for publications. For latest updated drawing please contact beamline scientist.
Schematics of the USAXS - SAXS - WAXS instrument with all three geometries. Data are collected sequentially using the three devices. Change over time between detectors is about 30 seconds.
An in-situ USAXS-SAXS-WAXS study of precipitate dissolution and size evolution in a model gamma-gamma Prime ternary Ni-based alloy (collaboration with Dr. G. Muralidharan, ORNL). A 0.1 mm thick sample was heated from RT to 1100C at 4.5C/min while undergoing repeated USAXS-SAXS-WAXS (24 keV) at 5 minute intervals. Research sponsored by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, as part of the Propulsion Materials Program.
USAXS/SAXS/WAXS data : In situ data collected at 226 °C over about 16 hours represent microstructure evolution of AA2024 aluminum alloy (Allen, Levine, and Zhang, NIST). USAXS data enable quantification of second phase formation (size and volume), WAXS enables phase identification.
Scattering of 1 micron SiO2 spheres in aqueous solution.
USAXS/SAXS/WAXS in situ data : Data collected by LLNL (Trevor Willey et.al.) on high-explosives. The material is composite of two high-explosives and plastic binder. The WAXS clearly shows phase changes while USAXS/SAXS data show microstructure change as function of heating.
Scattering of 1 micron Polystyrene spheres in solution.