Resources
For information regarding remote data access, please see this link: Remote Data Access
The following is a guide for data processing and software used at the XAS Beamline
Step 1: Inspect data
Within your experiment folder, you will notice a folder called ‘raw’, and a folder called ‘results’.
Raw data are saved as .netCDF and a .hdf5 files (transmission is just .netCDF files only). The beamline software will automatically generate a readable .xdi format text file for you in the ‘results’ folder.
If you collected fluorescence data, a pre-processing tool is also available at the beamline which allows you to inspect spectra from individual detector channels, adjust the Region of Interest (ROI) around the fluorescence peak of interest, and re-generate an updates .xdi file if needed (in a folder called ‘processed’).
It’s a good idea to continually check that all data files are being saved and appearing in your results folder, and the data looks as you would expect (load into an analysis software to check this, see below).
Step 2: Analysis
You may choose to use any data analysis package that you are familiar with. At the beamline we often use the IFEFFIT package for data reduction (Athena) and data analysis (Artemis). Further information and downloads (incl Athena, Artemis, and Hephaestus) can be found here: https://bruceravel.github.io/demeter/
A more recent (and potentially better!) alternative is Larch. Why not give it a go today and tell us what you think: https://millenia.cars.aps.anl.gov/xraylarch/
The beamline scientists are experienced in XAS data analysis and can provide some general advice in this regard. Please note, however, that it is not a specific task of the beamline scientists to analyse data for users and thus, should you wish to, please pursue their assistance in a reasonable manner.
Online Workshops and Tutorials
Helpful tutorials can be found online to assist with XAS data analysis. For example:
Software help with Athena/Atemis: https://bruceravel.github.io/demeter/
IFEFFIT mailing list: https://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit/
A webpage sponsored by the International XAFS Society with a wealth of resources: https://xafs.xrayabsorption.org/
Online Bruce Ravel XAS courses here: https://vimeo.com/search?q=bruce+ravel+xas+course
and here: https://vimeo.com/channels/exafsOnline EXAFS shell fitting workshop by Matt Siebecker: https://www.youtube.com/watch?v=Il_wRqhqFM4&feature=youtu.be
Shelly Kelly et al. (2008) Soil Science Society of America, Methods of Soil Analysis. Part 5. Mineralogical Methods. Analysis of soils and minerals using X-ray Absorption Spectroscopy, Chapter 14.
Available online here: https://www.semanticscholar.org/paper/Analysis-of-Soils-and-Minerals-Using-X-ray-Kelly-Hesterberg/8e4c088837e9c0cf8d5d96d6c1b528ff23b9c1c9EXAFS for Everyone (2013) by Scott Calvin - copy available at the beamline