Measurement of the Energy of X-Ray Absorption Edges

The well-known lattice parameter of silicon is taken as a reference value for the determination of the absolute energy of X-ray absorption spectra. First experiments at the K-edge of Ni, Cu, Zn and at the LII-edge of Yb are performed using synchrotron radiation from the storage ring DORIS. Whereas the values of the K-edges agree well with tabulated data, there is a discrepancy of about 4 eV between the measured value of the LII-edge of Yb and the value published in the literature.