I am working on some data processing of ZrO2 thin films collected in fluorescence mode, and had a question regarding the background subtraction in Athena. When I use the default values, I see a large negative spike in the background curve (shown in BGsubtract1.png). I can vary the spline clamps and other parameters to reduce this (BGsubtract1.copy), but it does not seem to have any significant effect on the final EXAFS (EXAFScompare.png).

My question is, do large spikes/instabilities on the edge like this need to be accounted for, or are they ok as long as the background fit after the edge seems fine? My thought is that as long as the EXAFS is not significantly affected, it should be fine, but I do not have a good sense for how the presence of this peak may impact the background curve beyond the absorption edge. I have also attached the project file in Athena for reference.

Thanks,

-Nathan