Threshold Behavior Of The M-Shell Photoionization Of Argon

The multiconfiguration Hartree-Fock method, which has been extended to study photoionization of atoms, is applied to calculate the 3s→kp photoionization cross section of argon. It has been shown that the interchannel interaction associated with the 3p→kd transition, which is very strong in the 3s subshell photoionization cross section, can be very efficiently simulated by the bound-continuum channel interaction associated with the 3p→3d transition. The length and velocity forms of cross section agree very well throughout the range of energies considered. Our results compare well with other theoretical estimates and are in better agreement with experimental measurements