$2p$ photoelectron spectra and linear alignment dichroism of atomic Cr

The $2p$ photoionization of free Cr atoms has been studied. Unpolarized as well as laser-aligned Cr atoms have been ionized with linearly polarized undulator radiation well above the $2p$ ionization thresholds. The investigation of the main and satellite $2p$ photoelectron lines and of the linear alignment dichroism allowed for a detailed characterization of the Cr $2p$ photoionization process. The spectra are compared to the predictions of the pure $\mathrm{jK}$ coupling model and to the results of intermediate coupling Hartree-Fock calculations. The importance of the investigations for the discussion of the $2p$ photoelectron spectra of bound $3d$ transition-metal atoms is pointed out.