Thanks for your suggestions. I just checked my original data without normalization. The edge step is about 0.7 (see pic attached). I did the measurement in fluorescence mode at APS, beamline 12-BMB. What do you think about this pic?

For the sample preparation, I think I need to mix UO2 with some other materials to dilute it. Do you have any suggestions on the matrix materials?

Best,

Ke