So your goal is to plot If/I0 versus time for a given energy in the XANES. Are you exporting normalised XANES or just If/I0? Are you doing background removal from the pre-edge? Is another feature underlying this targeted feature also disappearing or changing? i.e. you are not watching a feature increase from zero but instead changing from one to another? ...or seeing a background increase as well? Was the fluorescence measured using a solid state detector? Did the deadtime of the detector increase significantly as the signal from the sample increased (and no deadtime correction applied) ? -R. On Thu, Feb 16, 2023 at 10:53 AM Roberta Candela wrote:

Ha no worries! It would be Ifinal over time (to my vague understanding). I’m trying to show that the sample was saturated by looking above the fluorescence k-alpha line (or I guess it’s called the white line?) because the intensity should increase and then level off once it’s saturated. This is a xanes scan but we were doing fluorescence instead of transmission since it was a dilute sample. Did that answer the question? My apologies I’m very new and I’m sure im referring to things incorrectly.

Sent from Yahoo Mail for iPhone https://overview.mail.yahoo.com/?.src=iOS

On Thursday, February 16, 2023, 12:45 PM, Carlo Segre wrote:

Hi Robert:

What, exactly are you interested in plotting? It is not quite clear from your message. Is it the Io as a function of time during a scan? Is it the XANES scans as a function of time for a reaction?

Carlo

On Thu, Feb 16, 2023 at 11:59 AM Roberta Candela wrote:

Hi all, I am attempting to graph a simple plot of intensity vs time for some supplemental info on a paper (from XAFS data from beamtime). I thought it should be simple enough since I can export I0 and If from Athena and I know the run time and time per data point but I can’t get anything that looks remotely like the logarithmic graph it should be. Am I missing some big fundamental point for why this isn’t possible? My apologies if this is way too vague!/I feel like I’m missing something super obvious Thank you for your time! Sincerely -B

Sent from Yahoo Mail for iPhone https://urldefense.com/v3/__https://overview.mail.yahoo.com/?.src=iOS__;!!IK... _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit https://urldefense.com/v3/__http://millenia.cars.aps.anl.gov/mailman/listinf... Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit https://urldefense.com/v3/__http://millenia.cars.aps.anl.gov/mailman/options...

-- Carlo U. Segre (he/him) -- Duchossois Leadership Professor of Physics Professor of Materials Science & Engineering Director, Center for Synchrotron Radiation Research and Instrumentation Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://phys.iit.edu/~segre https://urldefense.com/v3/__http://phys.iit.edu/*segre__;fg!!IKRxdwAv5BmarQ!... segre@debian.org

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov https://urldefense.com/v3/__http://millenia.cars.aps.anl.gov/mailman/listinf...

Unsubscribe: https://urldefense.com/v3/__http://millenia.cars.aps.anl.gov/mailman/options...

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

OK...my first impulse would be to plot the full unnormalised XANES on the same graph so you can see the features grow in or change. If there are a large number of scans, maybe only plot every 3rd or 4th or such. You might find a better point to examine for time dependence than the one you had used. Sorry...I'm not clear on the type of experiment. Is it something where the concentration should be increasing, like dissolving in solution, or a chemical change - concentration of target element is constant, but chemical form changes, so features in the XANES are changing or shifting. In the datafile, are there column headings? Do any of them indicate a dead time corrected value? You may need to ask the person who collected the data or the beamline if such a correction is warranted. More generally, how much background in X-ray work do you have? Have you had a course on it? Do you know how dead time arises for a solid state detector? If you are looking at the increasing concentration scenario, as the signal rises, the detector has to reset before counting more. The higher the signal, the more time spent resetting instead of counting - the time over which the detector is live is less than the real time over which you are integrating. A strong white line feature could be a bad choice for monitoring over time in this regard without the correction. Look at other features. Is there a pre-edge feature you could use? Even the pre-edge background could be indicative of concentration saturation. If it is the chemical change scenario, then just look for when it stops changing. Sorry if this is vague. Hope it helps. -R. On Fri, Feb 17, 2023 at 11:16 AM Roberta Candela wrote:

Yes I think that would be the plot. I currently haven’t been normalizing anything as I was just trying to see if I could get a rough draft. I haven’t done any background removal it was essentially just the raw data. As far as the features go I am not sure? I wasn’t trying to target a specific feature. The fluorescence was measured using a solid state detector but I’m not sure about the dead time. Is that information that is contained in xdi files? I wasn’t at this particular beam time so I have only the file to work off of. Thank you so much for the detailed response! -B

Sent from Yahoo Mail for iPhone https://overview.mail.yahoo.com/?.src=iOS

On Thursday, February 16, 2023, 2:50 PM, Robert Gordon < ragordon@alumni.sfu.ca> wrote:

So your goal is to plot If/I0 versus time for a given energy in the XANES. Are you exporting normalised XANES or just If/I0? Are you doing background removal from the pre-edge?

Is another feature underlying this targeted feature also disappearing or changing? i.e. you are not watching a feature increase from zero but instead changing from one to another? ...or seeing a background increase as well?

Was the fluorescence measured using a solid state detector? Did the deadtime of the detector increase significantly as the signal from the sample increased (and no deadtime correction applied) ?

-R.

Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit