Modeling and basic data for streamer dynamics in N2 and O2 discharges

A second order hydrodynamics model of streamer dynamics is developed without using the classical restrictive approximations concerning the source term of the conservation equation of electron energy. The first three moments of the Boltzmann equation coupled to the Poisson equation for the space charge electric field are closed using the local energy approximation. The basic data needed for the present second order model for electrons and the first order model for ions are obtained from the solution of the steady state Boltzmann equation and the Monte Carlo simulation, respectively. The electron data associated with the source term of the electron energy conservation equation and which correspond to the different electron-molecule processes considered in our N-2 and O-2 discharges (ionization, attachment, excitation, elastic, and superelastic collisions! are explicitly given. Then, we give the results obtained with the present second order hydrodynamics model and concerning N-2 and O-2 gases at atmospheric pressure between parallel plate electrodes under overvoltage conditions. Comparisons are also performed with the results obtained from the classical first order model generally used in the literature. (C) 1998 American Institute of Physics. [S0021-8979(98)05220-7].