Non-Equilibrium Discharges

Steady-state regimes of non-equilibrium discharges are provided by a balance between generation and loss of charged particles. The generation of electrons and positive ions is mostly due to volume ionization processes (Section 2.1). To sustain the steady-state... 

In this relation, ki(Te) is the ionization rate coefficient and o is the neutral gas density. Criterion 4-15 actually restricts pressure, because Da a 1/p and o oc p. When pressure is low, non-equilibrium discharges are controlled by diffusion to the walls and surface recombination. When pressure exceeds 10-30 Torr (the so-called range of moderate and high pressures), diffusion is relatively slow and the balance of charge particles is due to volume processes ... 

Figure 4-16. Universal relation between electron temperature, pressure, and discharge tube radius in the non-equilibrium discharge regime controlled by diffusion of charged particles.

After decay of the non-equilibrium discharge, a new breakdown takes p ace a e distance between the electrodes and the cycle repeats. 

The most energy-effective mechanism for plasma-chemical NO synthesis is provided by the vibrational excitation of molecules, because most of the energy of non-equilibrium discharges is transferred from electrons to vibrational excitation of N2 molecules at Te =... 

Direct Plasma-Chemical Hydrazine (N2H4) Synthesis from Nitrogen and Hydrogen in Non-Equilibrium Discharges... 

The energy efficiency of this plasma-chemical process can be high, because it ean be effectively stimulated in non-equilibrium discharges by vibrational excitation of CO2 molecules. A relatively high process efficiency was achieved in experiments with non-thermal microwave discharge at moderate pressures (Garsky, Givotov, Ivanov, 1981). 

Relations (7-16)-(7-18) demonstrate that heating of a thin layer by short non-thermal discharge pulses provides significant local temperature increase in a thin surface layer without heating up the whole system. The gas temperature also remains low because of the application of strongly non-equilibrium discharges (Te > Tv > To). Based on relations (7-16)-(7-18) the heat flux go (7-13) required to provide a temperature increase AT in a layer with thickness h can be found as... 

Figure 8-16. Numerical simulation of NF3/O2 dissociation in the non-equilibrium discharge. Time dependence of the main species concentration. Initial mixture composition Ar = 67%, N2 = 3%, NF3 = 20%, O2 = 5.3%.

Contribution of Vibrational Excitation to Methane Conversion into Acetylene in Non-Equilibrium Discharge Conditions... 

CO in non-equilibrium discharges. Plasma co-production of CN and NO proceeds in this case by the following chain-reaction mechanism ... 

Table 9-19. Non-Equilibrium Discharge Conditions Typical for Achieving Specific Results of Plasma-Chemieal Treatment of Textiles and Related Materials... 

Non-Equilibrium Discharge Conditions and Gas-Phase Plasma-Chemical Processes in the Systems Applied for Synthesis of Diamond Films... 

Table 9-23. Typical Gas-Phase Composition in Non-Equilibrium Discharge System for Diamond Film Produetion in FI2-CFI4 Mixture...

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