DIRECT RADIATIVE RECOMBINATION AND PHOTOEFFECT CROSS-SECTIONS FOR ARBITRARY ATOMIC COULOMB BOUND-STATES

Simple exact analytical cross sections for direct radiative recombination (DRR) and atomic photoeffect for arbitrary (n, l, m ) states are obtained in the nonrelativistic Coulomb dipole approximation. These may also be used in the case of DRR or photoeffect on the Rydberg states of highly ionized atoms with N electrons by considering an effective ionic charge Z(eff) = Z - N. Asymptotic formulae in the energy of the incoming particle are derived. The numerical values of the DRR cross sections obtained with our formulae are in very good agreement with the existing numerical relativistic results. This is true for high Z values and large energies of the incoming electron.