Photoionization and photoabsorption cross sections of O, N 2, O 2, and N for aeronomic calculations

Abstract

A compilation of experimental and theoretical photoionization and photoabsorption cross sections is presented for O, N 2, O 2, and N for use primarily in studies of ion and photoelectron production in the earth's atmosphere. Since the last compilation of Kirby et al. ( Atomic Data and Nuclear Data Tables 23, 83 (1979) there have been numerous measurements taken related to these cross sections. We have tabulated these cross sections at the wavelengths of the solar lines and continuum given in the 1974 solar minimum reference spectrum, F74113, of Heroux and Hinteregger from 1027.0 to 23.7 Å, as well as for wavelengths where rapid variations occur in the cross sections. Whenever possible, autoionization states have been included and there has been no averaging over autoionization cross sections leading up to the thresholds of the ionic continuum states. This is the first compilation, in a comprehensive manner, to include the dense structure and autoionization structure in the photoabsorption and photoionization cross sections. The tables include, for the first time, cases where the photoionization and photoabsorption cross sections for atomic oxygen are not equal. Also, this is the first compilation to include the photoionization cross sections for atomic nitrogen and of multiple photoionization for atomic oxygen and nitrogen.