[Ifeffit] MBACK and Athena

[Bajamundi Cyril]

Dear Bruce,

The motivation for the question is that I'm concerned whether the shift in E values after calibration is conserved when the calibrated data has been saved in the .xmu file.  
But thanks to the link you have sent to me and your previous answer in the mailing list archive <<http://www.mail-archive.com/ifeffit@millenia.cars.aps.anl.gov/msg02755.html>> things are a bit clearer now. 
So here's a follow up. I have taken the following scans successively 
Cu foil
Sample1_scan1
Sample1_scan2
Sample1_scan3
I then process the data in Athena, to begin I calibrated the Cu foil spectrum, such that the nice orange circle falls at the tabulated value of 8979 eV. This in turn gives some "eshift" value of -0.360. What is the relationship of this eshift to the spectra of  sample 1, should I apply this eshift to the scans for sample 1 as? Definitely I can't apply the E0. 

This is still a bit vague  in my mind, even after reading the basic data processing section in the documentation. 
Thank you in advance.

Warm regards, 
Cyril

-----Original Message-----
From: ifeffit-bounces at millenia.cars.aps.anl.gov [mailto:ifeffit-bounces at millenia.cars.aps.anl.gov] On Behalf Of Bruce Ravel
Sent: Thursday, March 07, 2013 3:55 PM
To: XAFS Analysis using Ifeffit
Subject: Re: [Ifeffit] MBACK and Athena

On Thursday, March 07, 2013 12:10:26 PM Bajamundi Cyril wrote:
> 1.     Is this procedure valid? In the sense that no information or features
> of the spectrum are lost from merge.xmu to merged.xmu.mnor file.

Do you have some reason to believe that might be happening?  If so, perhaps you could ask a more explicit question.

> 2.     How will the procedure <Calibrate data> affect this procedure?

Calibration, as it is defined in Athena, is a procedure that changes *both* the E0 and the Eshift values so that a selected point in the spectrum has a selected energy value.

  http://bruceravel.github.com/demeter/aug/process/cal.html

I'm not certain I've answered your question, but I am unclear what is motivating your question.

B


--
 Bruce Ravel  ------------------------------------ bravel at bnl.gov

 National Institute of Standards and Technology  Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2  Building 535A  Upton NY, 11973

 My homepage:    http://xafs.org/BruceRavel
 EXAFS software: http://cars9.uchicago.edu/ifeffit/Demeter

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