Photoionization of atomic phosphorus from ground and excited states

Resonance structures in the photoionization of atomic phosphorus for the ejection of 3p or 3s electron from the ground 3s(2)3p(3) (4)Sdegrees and excited metastable (2)Ddegrees and (2)Pdegrees states have been studied in the R-matrix approach. Photoionization cross sections and photoelectron angular distribution asymmetry parameters are dominated by Rydberg series of autoionization resonances converging to several ionic thresholds. There are window resonances due to the 3s3p(3)((5)Sdegrees)np, 3s3p(3)((3)Ddegrees)np and 3s3p(3)((3)Pdegrees)np Rydberg series in the inner-shell photoionization from the ground state. Autoionizing states are identified and analysed to obtain resonance positions E,, effective quantum numbers n* and widths Gamma(r) using a procedure of eigenphase gradients. Our results for the 3s3p(3)((5)Sdegrees)np window resonances are in excellent agreement with the experimental values. Total and partial cross sections together with asymmetry parameter for leaving the ion in the ground 3s(2)3p(2) P-3 state have been calculated in both length and velocity formulations that exhibit very good agreement with each other.