Resonances in the simultaneous photoionisation and excitation of He

Abstract

The authors have investigated the simultaneous photoionisation and excitation of He, using the R-matrix method, for photon energies between 68 and 75 eV, covering the energy range of the resonances converging to the n=3 and 4 states of He+. Cross sections and asymmetry parameters for leaving the He+ ion in the individual nl states for n<or=3 have been calculated. Where possible, the authors have compared their results with those of recent experiments and good agreement is obtained.