USAXS Sample Holders
The USAXS instrument can accept a variety of relatively large and complex
sample holders. The sample-to-analyzer crystal distance can be relatively large
without negative influence on the measured data. Therefore it is possible to
mount complicated instrumentation in place of the sample.
We provide a couple basic types of sample holders for solids and liquids,
as shown. For other sample holders and apparatus, it is best to contact
the instrument scientist.
Single use liquid sample holders - user are ecnouraged to procure silicone isulators from Grace bio-labs which can be combined with two ~25micron thick glass microscopy cover slips to create single use liqid containers. We have designed convenient holders for various sizes and designs (JTR20-A2-1.0, JTR13R-A2-1.0 and JTR8R-A2-1.0), all 1mm thick. For special needs there is also sheet material (JTR-SA2-1.0), so custom containers can be made. Due to use of glasscover slips these cells need to be used at higher X-ray energies (above 10-11 keV). For weakly scattering samples you can use 2mm or even thicker (if available) cells, Grace-bio makes these up to 2.5 mm thickness and the plastic itself can be bought in number of thicknesses in McMaster-Carr (even though the sticky tape needs to be bought separately. AT 21-24 keV you can use easily 5mm path through water based samples and get better signal-noise ratio. Alternatively, these cells can be used with kapton sheets as window material. Minimum sample volume of the smallest container is 50 micro litres (8mm diameter opening, 1mm thick).
NOTE: Selection of these can be also found in sigmaaldrich.com catalog, search for "Grace Bio-Labs Press-To-Seal", make sure the title has "PSA both sides". Here is example of 25pc of 13mm dia hole with 2.5mm thickness for $95 (7-2016 price).
Note: The cost of these sample holders is quite singificant for us, and due to budget limitations we are unable to provide these sample holders for free. Please, buy your own. June 2014 costs are:
JTR8R-A2-1.0 (#666105), 8 samples/pc, $167 for 25 pcs (1mm, 2mm thick SigmaAldrich).
JTR20R-A2-1.0 (#666104), 1 sample/pc, $116 for 25pcs (1mm, 2mm, 2.5mm thick SigmaAldrich).
JTR13R-A2-1.0 (#666107), 1 sample/pc, $ 96 for 25pcs (1mm, 2mm, 2.5mm thick SigmaAldrich).
Capillaries for liquid samples: For users with sufficient amount of sample volume capillaries we tested and succesfully used NMR tubes. The NMR capillaries we have used are 4mm internal diameter, 5mm external diameter, with cap included. They provide ~3x better singal-to-noise ratio than 1mm diameter capillaries if transmisison is reasonable. For water/regular light solvent based samples and 18keV or higher X-ray energies these capillaries work fine. One source of these is here: Fisher scientific Wilmad Thin Walled High Throughput NMR tumeb (cat. No. 16-800-161). We hope to have these at the beamline (100 of these costs ~ $100) but I suggest users buy their own to make sure there is enough fo them. We have currently capillary holder which enables us to measure about 12 at a time. These capillaries also enable recovery of the sample after measurements.
Alternative capillaries we tested and succesfully use are melting capillaries, much cheaper than dedicated X-ray capillaries and much easier to use - and very good for samples with stronger scattering. One source of these is here: Kimbel Chase KIMAX Melting capillaries. We routinely have these at the beamline (as 100 of these costs ~ $20). Recovery of sample from these is difficult.
We also can use dedicated X-ray capillaries and our experience suggests, that 1 or 1.5mm capillaries from Charles Supper company are suitable for most needs. Thicker capillaries (2-5mm) are suitable (and better), though they get really expensive. At higher energies (21keV) we could usually measure 5 - 7 mm of water based samples and thicker sample provides better signal-to-noise data (at minor cost of Q resolution). It does not matter if capillaries are glass, borokapilalries, or Quartz. Thinner then 1mm are difficult to use in USAXS due to beam size. Since package of Charles Supper capillaries (25 pcs or less) costs around $130, we are unable to provide these to users. We simply do not have budegt for it. Recovery of sample is unlikely and yes, they break all the time.
Flow cell : many users want to study time resolved experiments using flow cell. We have currently reasonable success with our current setup using our persitatic pump and the NMR 4/5mm diameter tubes used for static samples. More details are on the Liquids page. Please read that you are suppose to purchase and send us before you come the necessariy tubing. Most of this materials are contaminated by the experiment and therefore are consumables. We cannot supply large quantities of tubing to all of the users. We do not have funding for it. We will supply short lengths and connectors.
Heating & cooling equipment: We have Linkam THM600 heating and freezing stage or Linkam TS1500 at the beamline available for users use. If you would like to use this stage for your experiment, please, contact instrument scientist during scheduling phase. You need to prepare samples suitable for a specific stage. For details on the stage, please see manufacturer's web site and/or talk to the staff.
Mail-in sample holders
Main-in samples are accepted at the discression of the USAXS staff and can be shipped only after prior agreement of the USAXS staff. Such samples have to satisfy very stringent requirements related to safety and handling... Note, that returning samples to users is quite complicated process (see Instruction for shipping materials from APS for details and review these instructions on what you need to provide). It is usually easier to dispose of the samples at the APS, so please, provide disposal instructions.
Samples must be mounted in one of these below listed two methods:
1. In 25 x 25 x 1.1 (or less) mm sample holders similar ot the Grace bio-lab cells JTR20R and JTR13R. Paper/plastic frames of same dimensions (25 x 25mm) can be made. Thickness can be less than 1mm as long as the frames are sufficently sturdy. These frames must have hole in the center with space for the sample. Maximum hole size can be ~18mm diameter, preferably smaller. Sample needs to be mounted approximately in the center. Minimum sample area available for X-ray beam is 2 x 2 mm. Samples should be supported from sides by tape - use 3M Scotch Magic tape or equivalent, not any other. The 3M Scotch magic tape has very little SAXS signal and is nearly ideal material for sample mounting. If necessary, back the sample with the 3M Scotch Magic tape. In that case send "empty" = sample holder with the tape layers you have used so we can measure it and subtract the tape scattering. For powders, put thin layer of powder on sticky side of this 3M Scotch magic tape and cover with second layer (sticky sides together). This creates little envelope with powder fixed between the tapes. Use powder sparingly, thin layers are required - thick layers of powder samples have multiple scattering! Mount these tape envelopes same as solid samples in frames.
Mark EACH frame with User name, Sample name (less than 15 characters, letters/numbers only). If data should be on absolute intensity scale include sample thickness in millimeters.
2. In Kimbel Chase KIMAX Melting capillaries (or equivalent) - see above for details. Do NOT send thin wall capillaries (Charles Supper), they breake too often in shipping and during sample manipulation at the beamline. Seal end of capillaries by epoxy or other appropriate and reliable method. Fill at least 5 mm of capillary with sample. Attach to the end of capillary sticker with user name and sample name. Sample name must be less than 15 characters (letters/numbers ONLY).
On the right is picture of some reasonably mounted samples:
Top: Liquid sample in Grace biol-lab cell with Kapton windows. Alternativelly, you can use also glass for the widnows. Use glass covers slips for microscopy, 25 micron thick, we use Fisherfinest "Premium Cover Glass" Catalog No: 12-548-C, 25x25mm - 1 (mil .. 25micron) from Fisher Scientific. Any similar should work just fine.
Center : Grace bio-labs cell mounted powder. Mounted between two 3M Scotch Magic tape layers and then taped over the center of the hole. Include same number of layers of the tape you used to be measured for instrumental curve.
Bottom: Carboard paper made holder for solid sample. This sample is held on its side by 3M Scotch magic tape. If the tape is not in the studied area, no need to send if for instrument background measurement.
Right: Capillaries. Fill at least 5 mm of capillary with the sample. These are KIMAX melting capillaries, 1.3 - 1.5 mm outside diameter. Seal safely. Attach label with user name and sample name.
INCLUDE capillary for measurement of instrumental curve. Either empty capillary or capillary filled with solvent... Whatever is appropriate for your samples, but we need the correct capillary to measure instrumental background.
Note each sample has user name, sample name and sample thickness on it. Sample thickness is in millimeters.
PRINT and make sure the names can be read easily. Watch handwriting!!! Include in the shippment and e-mail ahead separate list of sample names. Ship according to all valid rules, regulations, and other safety considerations (see shipping).