Xenon N4,500 Auger spectrum - a useful calibration source

In the xenon N4,5OO Auger spectrum there are 19 prominent lines ranging from 8 to 36 eV that provide a convenient set of standards for calibrating electron spectrometers. Combining optical data with recent measurements of this spectrum gives energies for these lines that are absolutely accurate to 11 meV. For most lines the relative accuracy is better than 1 meV; for a few it is about 3 meV. The spin-orbit splitting of the xenon 4d lines is measured to be 1979.0 +- 0.5meV.