Ion swarm data of N₄⁺ in N₂, O₂ and dry air for streamer dynamics simulation

Université de Toulouse, Laplace, UMR 5213 du CNRS, UPS 31062 Toulouse Cedex 9, France

Corresponding author: benhenni@cpat.ups-tlse.fr

Received: 4 July 2007
Revised: 11 September 2007
Accepted: 15 January 2008
Published online: 28 March 2008

Abstract

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.