Re: [Ifeffit] Ifeffit Digest, Vol 159, Issue 3

Dear All, Matteo It is difficult to do post facto, but if you have a well-defined solid, foil or crystal then mapping the thickness, measuring the mass and hence determining the mass per unit area, for the exact region illuminated by the beam, provides accurate units. Usually you will need to make a measurement of the average m/A from (i) total mass and (ii) total area, and then (iii) map the whole sample with X-ray tomography and (iv) the region illuminated by the X-ray beam. We have a series of papers which explain more than one methodology for doing that within the XERT technique. If your sample is a solution it is a bit more tricky, and I would refer you to recent JSR and JPCC papers for our Hybrid technique. Both can work well but need a bit more care than a normal XAFS measurement. Best wishes Chris ------------------------------------------------------------ Christopher Chantler, Professor, FAIP Editor-in-Chief, Radiation Physics and Chemistry Chair, International IUCr Commission on XAFS President, International Radiation Physics Society School of Physics, University of Melbourne Parkville Victoria 3010 Australia +61-3-83445437 FAX +61-3-93474783 chantler@unimelb.edu.au chantler@me.com http://optics.ph.unimelb.edu.au/~chantler/xrayopt/xrayopt.html http://optics.ph.unimelb.edu.au/~chantler/home.html ________________________________________ From: Ifeffit [ifeffit-bounces@millenia.cars.aps.anl.gov] on behalf of ifeffit-request@millenia.cars.aps.anl.gov [ifeffit-request@millenia.cars.aps.anl.gov] Sent: Saturday, 14 May 2016 3:00 AM To: ifeffit@millenia.cars.aps.anl.gov Subject: Ifeffit Digest, Vol 159, Issue 3 Send Ifeffit mailing list submissions to ifeffit@millenia.cars.aps.anl.gov To subscribe or unsubscribe via the World Wide Web, visit http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit or, via email, send a message with subject or body 'help' to ifeffit-request@millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner@millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. How to assign measure unit to XAFS data (Matteo Busi) 2. Re: How to assign measure unit to XAFS data (Alexey Boubnov) 3. Re: How to assign measure unit to XAFS data (Matt Newville) ---------------------------------------------------------------------- Message: 1 Date: Fri, 13 May 2016 02:11:39 +0200 From: Matteo Busi To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] How to assign measure unit to XAFS data Message-ID: Content-Type: text/plain; charset="utf-8" Hi Bruce, Matt, and mailing list readers, I have one question regarding the XAFS data. I have collected absorption coefficient in fluorescence regime of a CuSO4 penta hydrate sample(however my question can be generalized to any compound). Through Athena I then obtained the x\mu(eV) spectra as well as \chi(k) and \chi(R). I am wondering how can I assign a unit to the x\mu values. I would like to have it in the cm^-1 or cm^2 kg^-3 unit so than I can match it with tabulated data for the Copper absorption coefficient and proceed with my studies. In case a treatment is needed for the normalized \mu , that would also suit my situation. My idea was to divide by the thickness of the sample but I don't find a reasonable justificiation for this. I really hope I made the question clear to any reader this time, and if that is not the case I apologyze in advance. Best Regards Matteo