Re: [Ifeffit] Energy Resolution

Hi Carlo Thank you very much for your answer! If you say it is sufficient to use dk=0.05, that means I would be able to collect a full EXAFS spectra (k=0 to 12) in only 250 datapoints? That would save us a lot of time! Best, Julian -----Ursprüngliche Nachricht----- Von: Ifeffit [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] Im Auftrag von Carlo Segre Gesendet: Sonntag, 6. Mai 2018 01:07 An: XAFS Analysis using Ifeffit Betreff: Re: [Ifeffit] Energy Resolution Hi Julian: With an edge energy of 543 eV, your monochromator resolution should be at least 0.1 eV. If you are interested in XANES, you need to take data at this resolution or maybe even better. ONce past the edge, there is no need to keep that step size. If your beamline permits an EXAFS-type step scan with steps in k-space, you want to use a dk of 0.05 which is what IFEFFIT interpolates to. Smaller step sizes are not really useful. Carlo On Sat, 5 May 2018, Julian Ehwald wrote:

Dear all,

This might be a very general question, but: I was wondering what energy resolution you typically use at beamlines to obtain your raw data for exafs. Since we have limited Beamtime only and other experiments that we want to carry out, I was wondering what kind of resolution is common. Or differently: Is it predictable what happens if I for example change from steps of 0.2eV to 0.4eV? We want to obtain spectra up to 500eV above Oxygen K, if that is of relevance.

Best, Julian

-- Carlo U. Segre -- Duchossois Leadership Professor of Physics Interim Chair, Department of Chemistry Director, Center for Synchrotron Radiation Research and Instrumentation Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://phys.iit.edu/~segre segre@debian.org _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit