Studies of the photoionization cross section of the 2pi level of nitric oxide

Abstract

We present photoionization cross sections and asymmetry parameters for the 2pi level of nitric oxide which are obtained from the direct solution of the e+NO+ collisional equations at the static-exchange level. These cross sections differ significantly from those obtained previously using a moment theory approach [J. J. Delaney, I. H. Hillier, and V. R. Saunders, J. Phys. B 15, 1477 (1982)]. The calculated cross sections show a broad nonresonant feature at a photon energy of 29 eV which is not as pronounced as observed experimentally. The sigma shape resonance in our cross section occurs at 14 eV which is about 5 eV below the feature in the measured cross sections attributed to this shape resonance. The probable role of autoionization and vibrational averaging on these cross sections is also discussed.