The comparison of the relative sensitivity of X-ray Energy Dispersive Spectroscopy (XEDS) versus Electron Energy Loss Spectroscopy (EELS) has been a long standing debate in the Analytical EM community. While it is without question that the relative signal generation of EELS comparded to XEDS is greater, measures of the sensitivity have rarely been quantitatively assessed. A new figure of merit based upon the unbiased measurements of the variation of Signal & Signal/Background as a function of thickness has been developed and experimentally measured. As a function of thickness XEDS has been demonstrated to have better performance owing to it relative insensitivity to changes in the Signal/Background.
This research was funded in part by Laboratory Directed Research and Development (LDRD) funding No. 2017-153-N0 and the Photon Science Division at Argonne National Laboratory by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences , it employed, in part, resources in the Sydney Microscopy & Microanalysis, of the University of Sydney user facility.