Integral cross sections for electron impact excitation of electronic states of N₂

We report integral cross sections (ICSs) for electron impact excitation of the A ³Σ⁺_u, B ³Π_g, W ³Δ_u, B' ³Σ^-_u, a' ¹Σ^-_u, a ¹Π_g, ω¹Δ_u, C ³Π_u, E ³Σ⁺_g and a^{'' 1}Σ⁺_g electronic states of N₂. The present data, for each state, were derived at five incident electron energies in the range 15-50 eV, from the earlier crossed-beam differential cross section (DCS) measurements of our group. This was facilitated by using a molecular phase shift analysis technique to extrapolate the measured DCSs to 0° and 180°, before performing the integration. A comprehensive comparison of the present ICSs with the results of earlier experimental studies, both crossed beam and electron swarm, and theoretical calculations is provided. This comparison clearly indicates that some of the previous estimates for these excited electronic-state cross sections need to be reassessed. In addition, we have used the present ICSs in a Monte Carlo simulation for modelling the behaviour of an electron swarm in the bulk of a low current N₂ discharge. The macroscopic transport parameters determined from this simulation are compared against those measured from independent swarm-based experiments and the self-consistency of our ICSs evaluated.