Applying for beamtime at the AS MEX1 and MEX2 beamlines
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If you answer “NO” to any of these questions; STOP. Go back and take the necessary steps to answer “YES”, otherwise your proposal is likely uncompetitive.
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Proposed experiment:
“We will measure 64 ex-situ powder pellet samples at the MEX-1 beamline, (i) 13 powder standards of Br and Zn, and (ii) 51 samples in powder form sourced from our experiments conducted at XXX University. These samples will be produced at XXX University using a variety of treatment conditions and tested at the beamline ex-situ.
Sample Preparation: We will prepare powder pellet samples at our home institution or in the synchrotron chemistry lab the days prior to our beam time. The samples will be diluted with cellulose to approximately 1000 ppm of the target element for fluorescence-mode measurements, OR to an edge step in the range of XX <edge step value> for transmission mode. The mixtures will be made homogeneous using a mortar and pestle, compressed into a 7 mm diameter pellet using a hand press and mounted on a MEX-1 PMMA sample holder.
Beamline Setup: Using the Si(111) monochromator in step scan, we will measure the K edges for Br and Zn calibrated with Zn metallic foil, as K edges for Br and Zn fall at 13,473.7 eV and 9,658.6 eV. The sample environment will be room temperature and under helium. Data will be collected to reach K = XXX <k space value> for EXAFS with duplicate scans.”
Sample Table(transmission). Click here for edge step calculation
Sample Table
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Sample Table template BELOWTEMPLATE below. You may copy and paste this into your proposal and modify to suit your experiment. Concentration is particularly important for the beamline team to determine feasibility. Failure to provide an appropriate concentration increases the chances your experiment will be deemed infeasible. Furthermore, it is vital you know the composition of your sample if you want to make a successful x-ray absorption spectroscopy measurement. The way you present concentration in the sample table depends on the analysis mode (fluorescence, F; transmission, T; or drain current, D) you wish you use:
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A common mistake seen in proposals from the catalysis community is to report metal loading in the concentration column. A metal loading is not a concentration. Metal loadings do not help the beamline team assess whether your samples are appropriate for x-ray absorption spectroscopy measurements, but do communicate that you have failed to read this guide. Knowing only the metal loading also rarely helps you, the user, to prepare appropriate samples. If you do not know the exact composition of your sample, you are going to have to develop a strategy to produce samples which give you an opportunity measure good data. That may involve preparing the same material at a range of dilutions to cover the possible range of concentration of the element of interest. If you do not know your composition, and your amount of sample is limited, your experiment is likely to be difficult.
Sample | Sample form | Edge | Mode (F/T/D) | Concentration; |
incl. edge step (in transmission) | K max for EXAFS | Environment | Scans | Time/Scan |
(hrs) | Total |
(hrs) | ||||
Pt | Foil | Pt L3 | T | Δμd = 1 |
Tμd = 1.1 | 12 | 20, 50, 100 K | 36 | 0.5 | 18 |
FeS2 | Powder pellet | Fe K | T | Δμd = 1 |
Tμd = 2 | 18 | RT, He | 3 | 0.5 | 1.5 |
12 GaAs | Powder pellets | Ga K | T | Δμd = 1 |
Tμd = 2 | 12 | 20, 50, 100 K | 12 x 3 |
= 36 | 0.5 | 18 | |||||
Tissue samples (x8) | Cells on window | Br K | F | 0.1 to 0.5 mM | 16 | 10K | 8 x 4 |
= 32 | 1 | 32 | ||
5 Cr model compounds | Film | Cr K | F | diluted to |
1000 ppm | XANES only | 10K | 5 x 1 |
= 5 | 0.3 | 1.5 | |||||
15 Ir/Al2O3 catalysts | Coin cell | Ir L3 | F | 0.1 wt% | XANES only | RT | 2 x 15 |
= 30 | 0.3 | 10 | |||||||
4 S containing polymers, measured at 5 angles | S K | F, D | 20% | XANES only | RT, vacuum | 5 x 2 x 4 | 0.5 | 20 | |
Self absorption characterisation | S K | F | 0.1, 0.5, 1, 5, 10, 20% | XANES only | RT, Helium | 6 x 2 angles | 0.5 | 6 | |
Radiation hardness testing (hrs) | 2-3 | ||||||||
Beamline conditioning and training (hrs) | 4 | ||||||||
Total time requested | X hrs | ||||||||
(Y shifts) |
-Outcome of previous Australian Synchrotron experiments (past 3 years)
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