[Ifeffit] Question about ATHENA software

[Bruce Ravel]

Claudia,

The implementation of the XANES self-absorption corrections follows
the thing that Daniel Haskel wrote up here:

  http://www.aps.anl.gov/xfd/people/haskel/fluo.html

The algorithm used is explained on pages 5-9 of the postscript file on
that web page.  The angles are defined relative to the surface, not
the surface normal.

HTH,
B

PS: You should consider joining the Ifeffit mailing list:
(http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit).  It is a
very useful resource for siftware and for XAS in general.


On Saturday 07 November 2009 02:22:45 pm you wrote:
> Dear Bruce Ravel,
>
> I am a PhD student currently working with the ATHENA software. I came
> across a question which I could not answer even after searching the
> internet for hours. I hope you might have the time to briefly answer my
> question.
>
> The self-absorption dialog requires the incoming (angle in) and the
> outgoing angle (angle out) as an input. My basic question is: Are these
> angles referenced to the sample surface or to the normal of the surface?
> I would not worry about that if I had measured in 45deg geometry (as in
> your tutorial example). However, I did not and therefore it makes a
> large difference.
>
> I strongly apologize bothering you with such a basic question.
> Many thanks in advance.
> Best regards,
> Claudia Fleischmann


-- 

 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

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