Photoelectron spectrometry of manganese vapor between 12 and 110 eV

The important dynamic parameters, partial photoionization cross section {σ} and angular distribution parameter β, have been determined for atomic Mn between 12 and 110 eV by electron spectroscopy with synchrotron radiation (ESSR). The single-electron photolines from the $3d$ and $4s$ subshells and the associated two-electron satellite lines were measured, and the resonance region of 3p→3d excitation around 50 eV was studied in detail. Absolute partial cross sections were derived. For the $3d$-subshell properties, we find good agreement with the many-body perturbation-theory calculation (MBPT) by Garvin et al. over the entire energy range and with the random-phase-approximation results by Amusia et al. over the $3p$ resonance region. Available calculation (MBPT) underestimates the enhancement of σ(4s) through the $3p$ resonance. Where overlap exists, the experimental data by Bruhn et al. and by Kobrin et al. agree well with our results. The work on Mn, taken in toto, provides a good overall understanding of the photoionization dynamics of the $3d$ transition series element Mn, which has a half-filled subshell, although a number of problems, e.g., two-and three-electron transitions and the low-energy region, remain to be further studied. A need for an accurate determination (5-10%) of the total photoabsorption cross section is indicated.