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Do you still have access to your sample mount? The most straightforward way would be to measure how much the sample was shifted up or downstream with a ruler as a starting point and see how much that improves things.<br>
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For the custom calibration approach: You can add custom calibrants to the drop down menu by creating a UserCalibrants.py file. There are instructions in the ImageCalibrants.py file in the GSAS-II folder for the exact formatting. This approach won't work if
the copper peaks aren't sharp enough. <br>
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Another approach would be to calculate the shift in expected vs measured position for each copper peak, then interpolate a smoothly varying function and apply that correction to your data. This will only work for peaks inside the range of the copper peaks--the
position of any peak at lower 2theta than the first Cu peak will be unreliable.</div>
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<div style="font-family:Tahoma; font-size:13px"><font size="2"><span style="font-size:10pt">--
<br>
Leighanne C. Gallington, Ph.D.<br>
Assistant Chemist<br>
Advanced Photon Source (X-ray Science Division)<br>
Argonne National Laboratory<br>
Argonne, IL 60439<br>
gallington@anl.gov</span></font></div>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> GSAS-II <gsas-ii-bounces@aps.anl.gov> on behalf of Agyeman-Budu, David Nana via GSAS-II <gsas-ii@aps.anl.gov><br>
<b>Sent:</b> Friday, May 21, 2021 3:17 PM<br>
<b>To:</b> gsas-ii@aps.anl.gov <gsas-ii@aps.anl.gov><br>
<b>Subject:</b> [GSAS-II] Calibration of histograms to known peaks</font>
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<div><font size="2" face="Calibri"><span style="font-size:11pt">
<div>Hello all,</div>
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<div>I am looking for assistance to calibrate my operando XRD images without using the default calibrants, but with Cu peaks in my data. I found out that the peaks in the my operando XRD data are shifted, and this is due to the sample-to-detector distance differences
between my LaB6 calibration measurement and the operando measurement (the sample cell mount increased the distance away from the detector). Even though I have a good calibration I cannot apply it correctly to reduce my data. It also seems that choice of calibrants
in the calibration controls are limited to what is available in the drop box. </div>
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<div>Any advice or help on this would be appreciated.</div>
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<div>Thanks,</div>
<div>David</div>
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