Photoionization of atomic phosphorus from ground and excited states

Abstract

Resonance structures in the photoionization of atomic phosphorus for the ejection of 3p or 3s electron from the ground 3s23p34So and excited metastable 2Do and 2Po 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 3s3p3(5So)np, 3s3p3(3Do)np and 3s3p3(3Po)np Rydberg series in the inner-shell photoionization from the ground state. Autoionizing states are identified and analysed to obtain resonance positions Er, effective quantum numbers n* and widths Γr using a procedure of eigenphase gradients. Our results for the 3s3p3(5So)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 3s23p23P state have been calculated in both length and velocity formulations that exhibit very good agreement with each other.