[Ifeffit] Athena: k-weight=3 in background removal problem

[Carlo Segre]

Hi Joseph:

On Mon, 7 Jul 2008, Joseph Washington wrote:

> Greetings all,
> I am an APS user and a graduate of XAFS Summer School - class of 2007 :)
>   We have been doing EXAFS analysis on Ge[2]Sb[2]Te[x] thin films. I
> noticed that at the Ge edge in particular, the k-weight value used in
> the background removal cannot equal 3, or else the background function
> no longer follows the data and oscillates wildly and/or it shoots up at
> the edge energy dominating the plot window. Values of 1 and 2 work fine.
> Even more puzzling is that this problem is inherent for the Ge edge of
> data taken over numerous runs, and for various samples (GST-224,
> GST-225, 226, 227).

COuld you tell us why you would like to use a k-weight of 3 in the 
background removal process?  I find that 1 (or 2 sometimes) is sufficient 
to get a good result.  I just checked on a recent data set and I agree 
that k-weight 1 nd 2 give nearly identical results but that k-weight 3 for 
the same parameters is slightly different.

It would help a lot if you oculd send a project file for us to look at.

Carlo

-- 
Carlo U. Segre -- Professor of Physics
Associate Dean for Special Projects, Graduate College
Illinois Institute of Technology
Voice: 312.567.3498            Fax: 312.567.3494
segre at iit.edu   http://www.iit.edu/~segre   segre at debian.org