Dear Rietvelders,
Thanks for your opinions!
The "re-binning" of 1D data was done by my measurement software automatically,
rather than by analysis software.
The CPS is unchanged after its "re-binning". This means, rather than adding
counts of neighboring steps, it is *averaging* my data (sum counts up then
divided by the number of combined bins)!
I have a feeling what my measurement software doing is not correct...
--
Dr. Xiaodong (Tony) Wang
Research Infrastructure Specialist (XRD)
Central Analytical Research Facility (CARF) | Institute for Future
Environments
Queensland University of Technology
在 2019-09-27 10:31:45，alancoe...@bigpond.com 写道：
Hi Tony
>My I ask is this re-bined data from the measurement software considered as
>"raw data" or "treated data"?
I’m not sure what is meant by treated data. Almost all neutron data and
synchrotron data with area detectors are “treated data”.
If the detector has a slit width in the equatorial plane that is 0.03 degrees
2Th then it makes little sense using a step size that is less than 0.03/2
degrees 2Th. If rebinning is done correctly (see rebin_with_dx_of in the
Technical Reference) then rebinning is basically collecting redoing the
experiment with a wider slit.
In the case of your PSD then the resolution of the PSD would be the smallest
slit width. If the data has broad features relative to the slit width then
rebinning (or using a bigger slit width) should not change the results. You
could simulate all this using TOPAS to see the difference. Correct rebinning
should not affect parameter errors.
This is a question that is not simple to answer and if there’s concern then:
Simulating data with the small step size and performing a fit
And then rebinning with various slit widths and then fitting
And then comparing parameters errors and parameter values for all the
refinements should shine light on the area.
I don’t know where but I feeling is that there should be papers on this.
Cheers
Alan
From: rietveld_l-requ...@ill.fr <rietveld_l-requ...@ill.fr> On Behalf Of iangie
Sent: Thursday, September 26, 2019 1:40 PM
To: rietveld_l@ill.fr
Subject: Software re-binned PD data
Dear Rietvelder,
I hope you are doing well.
It is generally acknolwdged that Rietveld refinement should be performed on raw
data, without any data processing.
One of our diffractometer/PSD scans data at its minimal step size (users can
see that the step size during scan is much smaller than what was set), and upon
finishing, the measurement software re-bin the counts to the step size what
users set (so the data also looks smoother, after re-bin).
My I ask is this re-bined data from the measurement software considered as "raw
data" or "treated data"? And can we apply Rietveld refinement on this data?
Any comments are welcome. :)
--
Dr. Xiaodong (Tony) Wang
Research Infrastructure Specialist (XRD)
Central Analytical Research Facility (CARF) | Institute for Future
Environments
Queensland University of Technology
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