Determination of electrodynamic parameters of Axially heterogeneous high-frequency torch discharge plasma

In the present work we analyzed the influence of torch discharge plasma heterogeneity on the character of electromagnetic field attenuation along the discharge axis. A discharge burning in air at atmospheric pressure was analyzed. When taking discharge filament heterogeneity into account, two factors were considered: axial heterogeneity of discharge filament specific conductivity and diminishing of the filament radius along the discharge axis, i.e. changes in its shape. Axial distribution of discharge plasma specific conductivity was determined on basis of axial distribution of gas temperature. The gas temperature was measured on basis of relative intensity of rotational transitions of hydroxyl 3064 Å molecular band. The electrodynamic task was solved on basis of discharge filament model as a heterogeneous current line. When making calculations the obtained axial distribution of discharge plasma specific conductivity was taken into account. The discharge filament shape was assumed to be conical. As a result of calculations it was ascertained that electromagnetic field attenuation along the discharge axis proceeds under the linear law, which is in agreement with the experimental data obtained earlier. It was also revealed that torch discharge plasma is characterized by higher nonequilibrium than it follows from the analysis of the balance of chemical reactions in discharge plasma.