Efficient generator of low-temperature argon plasma with an expanding channel of the output

To study the thermophysical, electrophysical and optical properties of argon, as well as the implementation of various plasma-chemical reactions, a direct-current generator of a high-enthalpy argon plasma jet with a self-adjusting arc length and an expanding channel of the output electrode has been developed. A comparative analysis of the electrophysical characteristics (current–voltage characteristics—CVC, efficiency) in the expanding and cylindrical channels of constant cross section was carried out. Electrical, calorimetric and spectral studies have shown that the created generator of low-temperature plasma provides the formation of a slightly divergent plasma jet of argon with a diameter of $5$–$8 \times 10^{-3}$ m and enthalpy of $5$–$10$ MJ/kg and a mass-average temperature at the outlet of the gas-discharge channel of $5$–$12 \times 10^3$ K with an electron concentration in the axial plasma of $10^{17}$ cm$^{-3}$, the total electric power of the arc discharge $2$–$10$ kW and the plasma-forming gas consumption rate of $1.5$–$3 \times 10^{-3}$ kg/s. Depending on the initial conditions at a distance of $0$–$3 \times 10^{-2}$ m from the nozzle section of the low-temperature plasma generator, the plasma flow velocity varies from $990$ to $300$ m/s.