Mail-in program

!!! Important — the mail-in program is available only to current, approved APS users. Non-APS requesters will have to first register as APS users and be approved — and may be asked to submit a rapid access proposal !!!

How it works

Mail-in samples are accepted at the discretion of the USAXS staff and can be shipped only after prior agreement with the USAXS staff. Samples must satisfy stringent safety and handling requirements: we accept only samples that are safe, easy to handle, require no processing at the APS, and can be measured at room conditions. Samples must also be safe for staff to handle without specific training.

1. First, e-mail us at [email protected] and describe your needs. Samples MUST be approved by beamline staff before shipping. Inform staff of any safety issues; staff will get approval from the APS safety group before these samples can run.
2. If beamtime is available and the experiment is acceptable, we will provide further instructions, including dates. Beamtime is first-come, first-served.
3. Prepare and label your samples as described below, then ship them following our shipping instructions.

Mail-in users do NOT come to the ANL site or the instrument, and are not allowed to control the USAXS instrument or perform any work on site, unless specifically arranged (which will likely require an ESAF).

Before asking for measurements, check that your sample scattering can be detected above our instrument background — see this YouTube movie about our modeling tool. If you need help, talk to staff.

Accepted sample types

Only limited types of samples are accepted:

1. Solid samples (solid pieces or powders in pouches) mounted on sample plates
2. Liquid samples in NMR tubes or melting capillaries

If your samples need different mounting, talk with staff and get prior approval!!!

Rules for every sample

• Mark EACH sample, holder, frame, capillary, etc. with: user name and sample name (fewer than 15 characters, letters/numbers only). If data should be on absolute intensity scale, include sample thickness in millimeters. PRINT so the names can be read easily — watch handwriting!!! Include a separate list of sample names in the shipment AND e-mail it ahead.
• Calculate the necessary sample thickness for ~21 keV X-rays ahead of time (or talk with staff). Sample transmission should be higher than 20%. Use the Irena anomalous scattering calculator to estimate transmission — covered in the same YouTube movie. Do NOT send beamstops.
• Tape: if you need tape for mounting, use 3M Scotch Magic tape. It has very little SAXS scattering and absorption — of all available tapes it is by far the best, if suitable for your material.
• Blanks: if samples are covered by anything (tape, foil, windows), include the SAME material without sample (over an empty hole, in an empty washer, or an empty/solvent-filled capillary) so we can measure the instrument background.

Sample mounting and preparation

Solid samples on acrylic plates

Solid samples need to be pre-mounted on acrylic sample plates, which we can mail to users before experiments — request them at least 3 weeks before your beamtime. Users can also 3D print or mill their own (drawings available). Pre-mount your samples on the plates and ship them back to arrive at least 3 days before the scheduled beamtime, together with an Igor experiment with filled sample tables (or an Excel spreadsheet if you do not have Igor Pro). This is similar to the remote access instructions — check the resources there.

Resources: YouTube movie — how to survey samples at home before shipment, Indra manual page for this tool, PDF instructions.

Option A — flat pieces: rubber, plastic pieces, etc. can be mounted as flat pieces taped to the mounting plate (3M Scotch Magic tape). Sample size should be about 10×10 to 20×20 mm (not larger if at all possible), thickness preferably 2 mm or less (thicker samples are difficult to mount). Write the name on each sample or an attached label, and include a sample list with names and thicknesses in [mm]. Staff will not measure sample thickness for users — such data cannot be placed on absolute scale.

Option B — washers (recommended for powders and small pieces): mount powders or solids inside metallic or plastic washers. Our acrylic plates ideally fit 1/4" × 5/8" OD SAE Type A narrow flat washers, low carbon steel — cheap and a very good size — but any washers of suitable size and thickness work (even plastic). Cover the washer opening with Scotch tape (very low SAXS signal); Kapton is usable but has a broad diffraction peak around 0.3 Å⁻¹ that is difficult to subtract due to material variability. Minimum sample area for the X-ray beam is 2×2 mm. Washer-mounted samples can be quickly attached and removed at the beamline, making setup efficient. Include an empty washer with the same window material. Mount the washers to the plate surface with Scotch tape.

Figure: Washer-mounted samples. Scotch tape is used as windows on both sides of the washer.

Option C — frames (25 × 25 mm): holders similar to Grace Bio-Labs cells JTR20R and JTR13R, or paper/plastic frames of the same dimensions (e.g., punched from plastic or paper sheet; thickness under 1 mm is fine if sturdy). The center hole can be up to ~18 mm diameter, preferably smaller, with the sample mounted approximately in the center and supported from the sides by 3M Scotch Magic tape (no other tape). If necessary, back the sample with the same tape — and send an "empty" holder with the same tape layers so we can subtract the tape scattering. For powders: put a thin layer of powder on the sticky side of the tape and cover with a second layer (sticky sides together), creating a little envelope with the powder fixed between the tapes. Use powder sparingly — thick powder layers cause multiple scattering! Mount these tape envelopes in frames like solid samples.

Liquid samples

Preferred: NMR tubes — 4 mm internal / 5 mm external diameter, reliably sealed by the included cap. They provide ~3× better signal-to-noise than 1 mm capillaries if transmission is reasonable; for water or regular light-solvent samples at 18 keV or higher they work fine. One source: Wilmad thin-walled high-throughput NMR tube, Fisher Scientific cat. no. 16-800-161. Label each tube with user name and sample name at the top and seal properly.

Optional: KIMAX melting capillaries (Kimble Chase, or equivalent), 1.3–1.5 mm outside diameter. Do NOT send thin-wall capillaries (Charles Supper) — they break too often in shipping and during handling. Seal the ends with epoxy or another reliable method. Fill at least 5 mm of the capillary with sample. Attach a sticker with user name and sample name to the end.

Ship liquids to staff; staff will mount them into our liquid holders. (We are developing a holder for 100 custom short NMR tubes for future use.)

INCLUDE a capillary/tube for measurement of the instrumental background — empty or solvent-filled, whatever is appropriate for your samples.

If your samples need different mounting, talk with staff and get prior approval!!!

Correctly mounted samples (examples):

Examples of correctly mounted samples. Top: liquid sample in a Grace Bio-Labs cell with Kapton windows; glass also works — use microscopy cover slips, 25 µm thick (we use Fisherfinest Premium Cover Glass, cat. no. 12-548-C, 25×25 mm). Center: Grace Bio-Labs cell with powder mounted between two 3M Scotch Magic tape layers, taped over the center of the hole — include the same number of tape layers for the instrumental curve. Bottom: cardboard holder for a solid sample, held on its side by tape; if the tape is not in the studied area, no need to send it for background measurement. Right: KIMAX melting capillaries — fill at least 5 mm, seal safely, label. Note each sample has user name, sample name, and thickness (in mm) on it.

NMR tube filled with sample. Notre, we really need only about 10mm of liquid from thebottom, no need to fill whole NMR tube. 

Shipping and sample return

Ship according to all valid rules, regulations, and safety considerations — see our shipping instructions. Returning samples to users is a complicated process; it is usually easier to dispose of the samples at the APS, so please provide disposal instructions with your shipment.

Your data

The instrument delivers fully normalized, calibrated, and desmeared data in NXcanSAS HDF5 files (ASCII on request); see the Data section of our main page for a full description. Helpful resources: YouTube movie about our data, Indra manual.

Publications

Users are encouraged to publish mail-in data if possible. Since the program uses staff beamtime, publication requires beamline staff as co-authors. Mail-in requesters are the data custodians and must follow these rules: APS use MUST be acknowledged; the beamline must be cited as the source of the data; and manuscripts must be sent to USAXS staff for review before submission.