Nonequilibrium dissociation mechanisms in low temperature nitrogen and carbon monoxide plasmas

•The role of vibrational excitation in affecting N2 dissociation is put in evidence.•Calculations with new complete sets of e-N2 cross sections have been performed.•Vibrational mechanism dominates e-N2 dissociation for E/N < 50 Td.•Vibrational and electron dissociation mechanisms are competitive for E/N > 50 Td.

The role of vibrational excitation in affecting the dissociation under discharge conditions characterized by reduced electric field E/N ⩽ 80 Td has been investigated in N2. The kinetic calculations have been performed using a self-consistent approach, solving at the same time the master equation for the composition and the distribution of internal states (vibrational and electronic) and the Boltzmann equation for the electron energy distribution function. The results show that vibrational mechanisms involving heavy particle excited states dominate electron impact dissociation mechanisms involving the whole vibrational ladder for E/N < 50 Td, the two mechanisms being competitive for E/N > 50 Td.

Graphical abstractDownload full-size image