The photon energy dependence of the partial photoionization cross sections and branching ratios for CO and ${\mathrm{N}}_2$ have been measured using the continuum radiation produced by an electron storage ring. These measurements were conducted over the photon energy range of 14 to 50 eV. The partial photoionization cross sections in the energy region of the photoionization continuum are in good agreement with recent calculations where both the theory and experiment exhibit scattering resonances for specific states of the ion. The continuously variable photon energy source was utilized to examine the effect of autoionization on the partial photoionization cross section, showing in several cases quite different structure depending upon the final state of the ion.

• Received 17 November 1976

DOI:https://doi.org/10.1103/PhysRevA.15.2339