Differential and integral cross sections for the electron impact excitation of O2. II. Optically forbidden transitions from the ground state

Abstract

For pt.I see ibid., vol.11, no.22, p.3913 (1978). The electron impact excitation spectrum of O2 has been studied for the scattering angle range from 10 to 130 degrees and the energy-loss range from 0 to 7.1 eV. Differential and integral cross sections for excitation of the a1 Delta g and b1 Sigma g+ states and a group of states ranging from about 4.5 to 7.1 eV energy loss (broad maximum at 6.1 eV) have been determined in the impact energy ranges E0=20-200 eV, 20-150 eV and 20-500 eV, respectively. They are the first experimental data on the cross sections for excitation of these states at collision energies larger than 50 eV. The 6.1 eV broad peak is designated as the sum of the excitation to the A3 Sigma u+, C3 Delta u, and c1 Sigma u- states by virtue of the angular distribution and energy dependence of the differential and integral cross sections.