Writing the Proposed Experiment Text
The text of the Proposed Experiment section should give the reviewers and beamline team a sense of the experiment you intend to perform during your beamtime. The text, combined with the information presented in the sample table should demonstrate to the reviewers and beamline team that you have considered how best to prepare your samples for measurement, and have planned to use your beamtime efficiently. The text of the Proposed Experiment section should comprise several paragraphs describing your intended measurements, including information the nature of the samples you will be measuring, how they will be presented to the beam, the edges you intend to measure, etc.
Some examples of things to include in the text of the Proposed Experiment section (if relevant to your samples):
A brief description of your samples. Description of the samples should be restricted to information that is relevant to the measurements and other activities performed on-site. For instance, the Proposed Experiment section is not the place for a description of how you synthesised your sample material, although you should describe the form of the sample when it is presented to the beam. If you are modifying your material for measurement, e.g. homogenisation by grinding, diluting with cellulose or boron nitride, pressing into a pellet you should detail that in the experiment section. If you are preparing your samples on-site in the chemistry lab, mention that in this section.
If your samples are in-situ (battery cycling) you must describe your setup.
If you are presenting your samples undiluted you can detail how you know the abundance of the element of interest, e.g. previous bulk analysis by XRF or ICP-MS, quantification via EPMA or SEM EDS.
A justification of the energy range of your scans
A request for a particular DCM crystal based on inspection of the MEX1 DCM glitch maps
If you are planning on measuring particular samples as model compounds for linear combination fitting, you can explicitly mention that in this section, as it will help the reviewers assess if they are appropriate for your unknowns.
The composition of the sample beyond the element of interest is important information, as is the presence of other elements in the sample have edges or fluorescence lines that interfere with the element of interest. For example, measuring fluorescence mode EXAFS of 5 ppm Co in soil with 30 wt% Fe2O3 is unlikely to produce publishable-quality results due to the overwhelming fluorescence from the Fe K emission lines. Similarly, it is not possible to measure Ni K-edge (8333 eV) EXAFS to k=16 in a Ni-Gd alloy as the Gd L1 edge (8376 eV) will contaminate the Ni EXAFS. It is important that you consider possible interference from other elements when designing your experiment. If you are aware of the presence of interfering elements in your samples, use this section to describe how you will mitigate the interference.
If you do not know the composition of your samples, use this section to describe the strategy you will employ to measure samples of the appropriate concentration for x-ray absorption spectroscopy using your chosen analysis mode. The modes available at MEX1 are fluorescence or transmission. The modes available at MEX2 are fluorescence or drain current.
If you are unable to homogenise your sample (e.g. grinding will destroy fundamental features of your sample), use this section to describe how the form of the sample may impact the quality of data you will collect (e.g. pinholes, grain size much greater than 1 absorption length) and any mitigation strategies you propose to employ.
If you know your samples will exhibit significant over-absorption (a.k.a self-absorption), detail the methods you will use to correct over absorption, e.g. correlation with transmission or drain current, correction algorithms, grazing exit geometry.
If you are intending to perform radiation hardness/beam damage testing, detail your approach in this section.
If you think your samples may possess characteristics that will make measurement difficult, but are unsure how to proceed, contact the beamline team for advice.