Hi, Carlo,
Thanks for your physical explanation for the calibration.
I have another question. I measured the same element at different
beamlines. So if I want to compare different samples measured at different
beamlines, how should I do for this situation given the possible different
calibration
HI Haifeng,
Suppose you measure Fe foil three times, and all three scans overlap.
They are aligned.
But suppose the edge positions are at 7116 eV instead of 7112 eV. The
calibration is off.
You can adjust to it, but, as Carlo mentioned, it is really an angle
correction, not simply a
shift in
On 07/27/2018 01:32 PM, Haifeng Li wrote:
What is the real difference between calibration and alignment? Do they
have specific meaning?
In Athena, calibration means to determine a value for e0 shift such that
a particular point in the data is specified to be a particular energy.
Then the
Hi, Robert,
Thanks for your help.
One more question. What is the real difference between calibration and
alignment? Do they have specific meaning?
Thanks,
Haifeng
On Sun, Jul 22, 2018 at 5:45 PM, Robert Gordon
wrote:
> Hi Haifeng,
>
> Here's my take on what you described:
>
> Two sample to
The calibration should be done at the beamline with a foil. Once that is
done, then you don't really want to change it. Remember that just
shifting the energy is not actually the correct way to do a shift. The
energy shift is a non-linear function of the angle (Bragg's Law) and so
when
Hi, Carlo,
Thanks for your answer.
I may ask you more questions. Why you do not recommend to calibrate the
data? Calibration is used to find the E0 and match it to the literature
data. What is the real difference between calibration and alignment?
Thanks,
Haifeng
On Sun, Jul 22, 2018 at 5:30
Hi Haifeng,
Here's my take on what you described:
Two sample to be studied at the same edge using the same reference.
Three scans on A and three on
B are done with simultaneous reference.
First: compare the three reference scans for A. If they agree, then
compare the data scans. If they
Hello Haifeng:
Personally, I would not calibrate the data but merely align the references
of A2 and A3 to the reference of A1 and similarly align B2 and B3
references to that of B1. Once merged, you can then aligh the
reference of the merged B samples to that of the merged A samples.
If
Dear ALL,
I am a beginner in Athena. Recently I got the spectra and I am confusing
about the data calibration and alignment. The manual shows that calibrate
the reference data of one scan and align other reference data to that
calibrated one.
Here I want to show examples. I have two samples A
, April 14, 2009 11:10 AM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Basic questions
Dr. Kelly,
May I get a copy about setting k-range? Thanks1
Haiyan Zhao
Chemical Engineering Department
Virginia Tech
Blacksburg, VA 24060
Hi Andy,
I have a book chapter
Dr. Kelly,
May I get a copy about setting k-range? Thanks1
Haiyan Zhao
Chemical Engineering Department
Virginia Tech
Blacksburg, VA 24060
Hi Andy,
I have a book chapter that details how to set the k-range for a data
set. It also talks about Rbkg in detail. If you want a
Some really quick basic questions. I am working with EXAFS spectra of
silicate glasses at various edges (including S and Fe K edges) and I
am having a really difficult time pinning down the structures. Clearly
with glasses I can't always be sure of the oxygen co-ordination and so
I have to refine
Hi Andy:
On Mon, 6 Apr 2009, Andy Connelly wrote:
1. Are there any problems if I set the R-range min to the same value as Rbkg?
No, but you shouldn't set it lower than Rbkg, in general.
2. If I want to refine the degeneracy of a path can I write the
expression amp*N_1 in the SO2 box?
...@millenia.cars.aps.anl.gov] On Behalf Of Andy Connelly
Sent: Monday, April 06, 2009 12:16 PM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Basic questions
Some really quick basic questions. I am working with EXAFS spectra of
silicate glasses at various edges (including S and Fe K edges) and I
Hi Andy,
Just a few notes I'd like to add to Carlo's helpful answer:
On Apr 6, 2009, at 1:27 PM, Carlo Segre wrote:
Hi Andy:
On Mon, 6 Apr 2009, Andy Connelly wrote:
2. If I want to refine the degeneracy of a path can I write the
expression amp*N_1 in the SO2 box? (where the N box is
Hi Ashley:
I think you are struggling with one of the most difficult aspects of XAS
analysis. There is no single, automatic way of setting these parameters
although Athena and Ifeffit do a good job of initial guesses.
It is rather trite to say that it is a question of experience but that is
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