Correlation satellites in the photoelectron spectrum of argon

Abstract

Many-body perturbation theory has been used to calculate photoionization cross sections with excitation of neutral argon from the single-ionization threshold at 15.76 to 100.00 eV. Resonance structure due to both single-electron excitations (3s→np) and double-electron excitations (3$s^2$3$p^6$→3$s^2$3$p^4$mn) has been included. Calculated cross sections leaving the ion in 3$s^2$3$p^5$, 3s3$p^6$, 3$s^2$3$p^4$ ${(}^1$D)md${(}^2$S), and 3$s^2$3$p^4$4p${(}^2$P) levels are compared with experiment and previous calculations. Calculated cross sections for 3$s^2$3$p^6$→3s3$p^6$εp and 3$s^2$3p→3$s^2$3$p^4$4pεd/εs excitations were used to determine the satellite intensities, which are compared with photoelectron measurements and other calculations. Results are also presented for the total cross section and the angular-asymmetry parameter for 3p electrons.