Integral cross sections for the direct excitation of the A 3Σu+, B 3Πg, W 3Δu, B′ 3Σu?, a′ 1Σu?, a 1Πg, w 1Δu, and C 3Πu electronic states in N2 by electron impact

摘要

Integral cross sections for electron impact excitation out of the ground state (X 1Σg +) to the A 3Σu +, B 3Πg, W 3Δu, B′ 3Σu ?, a′ 1Σu ?, a 1Πg, w 1Δu, and C 3Πu states in N2 are reported at incident energies ranging between 10 and 100 eV. These data have been derived by integrating differential cross sections previously reported by this group. New differential cross section measurements for the a 1Πg state at 200 eV are also presented to extend the range of the reported integral cross sections for this state, which is responsible for the emissions of the Lyman-Birge-Hopfield band system (a 1Πg → X 1Σg +). The present results are compared and critically evaluated against existing cross sections. In general, the present cross sections are smaller than previous results at low impact energies from threshold through the excitation function peak regions. These lower cross sections have potentially significant implications on our understanding of UV emissions in the atmospheres of Earth and Titan.