Experimental and Theoretical Determinations of the5dPhotoionization Cross Section in Laser-Excited Barium Atoms between 15 and 150 eV Photon Energy

Abstract
We report the measured and calculated photoionization cross section of the excited 5d electron in neutral barium. The measurement and a local-density-based random-phase-approximation calculation show resonance enhancement of the 5d cross section when the 4d ionization channel opens. There is good agreement between the theory and experiment over a broad energy range.