APS USAXS/SAXS/WAXS facility

Ultra-Small-Angle X-ray Scattering Facility

On site experiments

On-site experiments

Most users are expected to come for in-person, on-site experiments, typically through the General User proposal system. Here is how it works: your proposal is reviewed, graded, and allocated beamtime based on its grade. Beamline staff schedule your experiment about a month before the start of the cycle (e.g., early January for the Feb–Apr cycle). You complete all required training and submit your Experiment Safety Assessment form (ESAF) at least 21 days before the experiment.

After on-site training by USAXS staff, you get full access to the USAXS instrument — and, when requested, the chemistry laboratory for sample preparation. You operate the instrument during your scheduled beamtime: you survey sample positions and collect data yourself, with staff available for support as needed.

Important scheduling rules

  1. Discuss safety issues with the APS safety group well ahead — months ahead. We have limitations on gases and chemicals which you may not expect. DO NOT assume; verify ahead.
  2. Arrive a day before your experiment, preferably before noon — talk with staff, finish training, prepare samples.
  3. Your data collection starts at 9 am (unless told otherwise). You are expected at the beamline by 8 am or as staff instructs.
  4. Bring a sufficient number of experimenters: at least two for more than 2 shifts, three or more for more than 6 shifts (see user instructions).
  5. Ship samples well ahead of the experiment start; build in a few days for delays in shipping and ANL on-site transport/delivery.
  6. Plan on shipping samples back yourself before you leave (there is paperwork) — or, preferably, plan on disposing of samples through the waste system (there is also paperwork). Nothing is fast!
  7. Plan to leave no earlier than 10am, preferably afternoon after your experiment ends. You need time to collect data, clean up, and have closeout discussions with staff. No 9 am flights!

Accepted sample types

Many sample types are accepted for on-site experiments:

  1. Solid samples (solid pieces or powders in pouches) mounted on sample plates
  2. Liquid samples in NMR tubes or melting capillaries
  3. In-situ heating experiments with the Linkam 600 or Linkam 1500 heaters
  4. Samples requiring chemical preparation work in the chemistry lab
  5. Radioactive, reactive, and other special samples that can be approved through the ESAF system — this often requires collaboration between the APS safety group, USAXS staff, and users. Check for any limitations with staff before proposing.
  6. User equipment, as long as it is suitable for the experiment, compatible with the USAXS instrument, and can pass safety inspection. Talk with instrument staff before proposing such experiments — it can be a tedious process.

All experiments must be approved by the APS safety group and beamline staff before they can run. Users must be approved APS users with all training up to date. All users must follow all APS/ANL regulations and staff instructions at all times.

After your experiment — your data

The USAXS instrument delivers fully normalized, calibrated, and desmeared data in NXcanSAS HDF5 files. For a full description of the data, formats, and absolute calibration, see the Data section of our main page and the user instructions.