Photoionization of calcium

Abstract

A study of the photoionization of calcium in the relativistic random-phase approximation is reported. Predictions of photoionization cross sections, angular distribution asymmetry parameters, and spin-polarization parameters for the $4s$, $3p$, and $3s$ subshells are made with emphasis on the energy region above the $3p_{\frac{3}{2}}$ threshold where multiconfigurational effects are not expected to be very important. Autoionization resonances below the $3s$ threshold and between the $3p_{\frac{3}{2}}$ and $3p_{\frac{1}{2}}$ thresholds are analyzed using the relativistic multichannel quantum-defect theory.