Physical proprieties of DC glow discharges in a neon-argon gas mixture

This paper reports a detailed study of 90% Ne – 10% Ar gas mixture DC glow discharge at low pressure, wherein 15 chemical reactions are considered. The second-order fluid model is used. The parameters of particle transport and their rate coefficients strictly depend on mean electron energy. In the framework of the local electric field approximation, we have developed an analytical expression of the drift velocity of positive argon ions in a neon gas W_Ar+^Ne, which is in good agreement with the experimental results, and serves to give best results than the results obtained using W_Ar+^Ne that exist in the literature. The results show that the argon ion density is more important than the neon ion density despite the presence of more constant background neon gas density in the mixture. The current density reaches 0.1729 mA/cm² for 250 V applied potential under 2 Torr pressure in a gas mixture. The spatio-temporal evolution of both electric and energetic characteristics, as well as their spatial distribution in the steady state, are shown and discussed. The maximum value of the neon metastable atom density is 4.54957 × 10⁸ cm^-3, and for argon metastable atom density is 5.4689 × 10⁸ cm^-3. The model is verified experimentally and theoretically in the particular case. (author)