Electron gas in discharge plasma in air

Conclusion We have presented a numerical solution of the electron Boltzmann equation in the two-terms approximation with given cross sections. The computations were performed for the electron gas in the dry air and a comparison with calculations in pure oxygen and nitrogen was made. Within the range of 2×10^–17 –4×10^–15 Vcm² of the parameterE/N the mean kinetic energy of electrons, drift velocity, characteristic energy and transverse diffusion coefficient were calculated and compared with the available experimental data. Greater deviations of the electron swarm parameters from their experimental values were found in the dry air than in pure oxygen or nitrogen. We have been unable to identify the cause of these discrepancies, which exceed a likely error incurred by the use of the two-terms approximation 17]. For instance, in the present calculations the maximum deflection of the computedD _T / from the experimental one in the case of dry air is about two times greater than in pure oxygen or nitrogen.In the determination of the collisional rates the correctness of the individual cross sections incorporated in the Boltzmann equation plays a crucial part. It seems that an error due to the existence of a great deal of uncertainty about the available cross sections prevails very likely over the others. Perhaps, only the Townsend ionization coefficient can be distorted by the use of the two-terms approximation more than by a possible error in the ionization cross section.