Photoionization of the 2p subshell of sodium atoms in ground and excited states.

Abstract

Photoionization cross sections and asymmetry parameters of photoelectrons resulting from ionization in the 2p subshell of excited-state 2${\mathit{p}}^{6}$3p $^{2}$${\mathit{P}}_{3/2}$ and ground-state 2${\mathit{p}}^{6}$3s $^{2}$${\mathit{S}}_{1/2}$ sodium atoms have been calculated using the multiconfiguration Hartree-Fock method over a large photon energy range. Calculations of relative intensities and branching ratios for leaving the positive ions in various final states corresponding to the main and satellite lines have been made and are compared with the available experimental measurements. It is found that there is a strong enhancement of the relative intensity of the shake-up satellite in the excited atom, in agreement with experimental observation. The asymmetry parameter \ensuremath{\beta} in the excited state agrees well with a recent experimental measurement made at a single photon energy. Further experimental work is needed to verify the theoretical results over a large photon energy range.