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

Abstract

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 [Formula: see text], which is in good agreement with the experimental results, and serves to give best results than the results obtained using [Formula: see text] 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.

Current-Voltage Characteristics in a Helium-Argon Gas Mixture Glow Discharge at Low Pressure

“…Therefore, the production of argon ions is more efficient than of helium ions during the ionization process. This phenomenon is also observed in the case of Ne-Xe gas mixture [10], and Ne-Ar gas mixture [11]. To conclude, the current-voltage characteristics in 90%He-10%Ar gas mixture approach the current-voltage characteristics in pure argon gas for a certain range of the electric potential, which are shown in Fig.…”

“…In our previous research [9][10][11], we have found that the EEDF is non-Maxwellian for a threshold value of pressure, and again, it is related to the type of gas. The percentage of gas in the mixture is related to the ion mass.…”

“…At low pressure, the destruction of the positive ions is negligible, and we can calculate the quantities S He m and S Ar m as follows [9][10][11]20]:…”

Identification of the normal and abnormal glow discharge modes in a neon-xenon gas mixture at low pressure

“…Then, a description of the model is given by equations (1) to (25). Note that the difference between the existing model and the model given by [7,8] is devoted to the presence of both a and b percentages of the gas as well as the positive ion mobility of each gas in the mixture. The flux expressions of a particle are given as follows [22,23]: The gas ion mobility in the mixture is determined according to equation (22).…”

“…In the research papers [7][8][9][10], we find that the electron energy distribution function (EEDF) can be Maxwellian at a very low pressure, and is related to the type of gas. The EEDF is non-Maxwellian for a threshold pressure value, and is again related to the type of gas.…”