The fact that we are seeing 1:100 Cu L a ghost intensity indicates that the anode is in good condition. Over time the Al anode material can pit or erode by essentially sublimating if there is not sufficient water cooling power. The Al anode material is actually attached to a copper block that is used for heat transfer to the water cooling. This peak only reflects about 1% or less of the total X-ray flux, and is an important diagnostic of the health of the anode. It is 556.9 eV above the C 1s peak generated by Al K α. The middle picture shows a Cu L α ghost peak for the Al anode. If one encounters a peak that one can not assign when using the Al anode, subtract 233.0 eV and see if there is a significant peak. As such the Mg K α ghosts when using the Al source are an issue only with the stronger detected lines. Comparing the area of this peak to the main C 1s peak, it amounts to about 1.5% of the total X-ray flux. If we look at the structure of the X-ray source, what is happening is that some small fraction of the electrons generated by the X-ray source filament are making it over the bridge separating the Al and Mg anodes and making Mg K α X-rays. This is actually a ghost peak from Mg K α radiation being generated within the X-ray source when set on Al K α. Possible assignments include V 2p and Re 4p- which are ridiculous.

It's too intense to the a satellite to the O 1s peak, and remains upon satellite deconvolution. In the first graph, 233.0 eV above the C 1s peak, just below the O 1s peak, is an unidentified peak. Some residual O 1s signal was present because of water physisorbed in the graphite film. In this study, graphite was flash coated on a 304 SS stub and sputter cleaned. For a given anode, these ghost peaks occur at a fixed binding energy interval above and below each peak.

Na auger xps peak