Photoion yield spectra of the lanthanides in the region of the 5p excitation: The elements Gd, Tb, Dy, Ho, Er, Tm, and Yb

The photoion yield spectra of singly and doubly charged lanthanides Gd, Tb, Dy, Ho, Er, Tm, and Yb were measured in the region of the 5p excitation between 20 and 40 eV. Monochromatized synchrotron radiation was focused on an atomic beam and a time-of-flight spectrometer was used for the charge-selective detection of the photoions. The interpretation of the experimental results is partly based on time-dependent local-density approximation calculations of the partial photoionization cross section of the subshells 4f, 5p, 5d, and 6s