The ion swarm data such as reduced mobilities, diffusion coefficients and
reaction rates of N4+ in N2, O2 and dry air (80%
N2, 20% O2) have been determined from a Monte Carlo simulation
using calculated and measured elastic and inelastic cross sections. The
elastic cross sections used have been determined from a semi-classical JWKB
approximation based on a rigid core potential model. The inelastic cross
section of N4+ in N2 has been deduced from the measured
experimental rates whereas for N4+ in O2 the measured
inelastic cross sections have been extended to low and high energies by
appropriate approximations. Then the cross sections sets have been validated
from comparison of calculated and measured ion swarm data. From the cross
sections sets obtained in pure N2 and O2, the ion swarm data for
N4+ in dry air are then calculated for a large E/N range
[1–104] Td. Finally, the influence of N4+ ions on the
streamer development was analyzed with a 2D fluid model in the case of dry
air at atmospheric pressure for a point-to-plane electrode configuration.