[Ifeffit] enrgy-axis-expansion

[Bruce Ravel]

On Monday 08 September 2008 14:03:05 Carlo Segre wrote:
> It sounds to me like the question is a bit more complex than that.  I
> believe that with their continuous scan electronics, they get absorption
> as a function of time, not energy.  If I am not mistaken, he is asking to
> have a conversion to energy built in somehow.

>From this, I finally understand the question.

Athena does not currently provide a mechanism for expanding the energy
axis.  I could be convinced to code that up, but I would need a
clearer statement of what you actually want done and several clear
examples of how to process the data correctly.

B




On Monday 08 September 2008 13:59:42 Anatoly Frenkel wrote:
> Khalid, what you can do is to note how much the higher energy (at energy
> E1) feature is shifted from what you think it should be (let's say by the
> amount of D eV), provided that you fixed the lower energy point to what you
> wanted (say, E0). Then, you should transfer the data into a spreadsheet and
> apply linear scaling:
>
>
>
> E --> E0 + (E-E0)*D
>
>
>
> It will ensure that in the range between E0 and E1 the data are linearly
> stretched or compressed, depending on the sign of D.
>
>
>
> Anatoly
>
>
>
> =
>
>   _____
>
> From: Khalid, Syed [mailto:khalid at bnl.gov]
> Sent: Monday, September 08, 2008 12:21 PM
> To: ifeffit at millenia.cars.aps.anl.gov
> Subject: [Ifeffit] enrgy-axis-expansion
>
>
>
> Is it possible in Athena to change the y-axis (energy
> scale) at two different energy points of an EXAFS scan?
>
> I have a Ni foil spectrum as a function of time.
> The edge can be set at 8333.0 eV, and I want to
> to assign higher energy to a known feature in the Ni scan.
>
>
> Syed Khalid
> 725D, National Synchrotron Light Source
> Brookhaven National Laboratory
> Upton, NY 11973
>
> Ph: 631-344-7496
> FAX: 631-344-3238
> e-mail: khalid at bnl.gov
>
> _______________________________________________
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.gov
> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit



-- 
 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/~ravel/software/exafs/