Thermal plasmas: production

Figure 1 - Evolution of the electrical conductivity of different plasma gases (Ar, Ar-H 2 (25% vol) and N2) as a function of the enthalpy h of the gas at atmospheric pressure.

Figure 2 - Radio-frequency coupling principle

Figure 3 - Cooled copper finger system used in high-power (≍ 1 MW) radio-frequency torches for spacecraft re-entry simulation

Figure 4 - Diagram of a Tekna radio frequency torch Ò[8] [9]

Figure 5 - Voltage distribution in an argon DC arc

Figure 6 - Principle of blown arches

Figure 7 - Principle of transferred arcs

Figure 8 - Hot-cathode torch operation

Figure 9 - Principle of a hot-cathode torch used for spraying

Figure 10 - Sultex Metco Triplex torch with three cathodes and segmented nozzle

Figure 11 - Plazjet® button-type hot-cathode torch with vortex gas injection

Figure 12 - Aerospace torch diagram [16] [24]

Figure 13 - Diagram of the Westinghouse torch

Figure 14 - Diagram of SKF torch

Figure 15 - Transferred bow

Figure 16 - Tetronics (GB) hot cathode principle for currents up to 8,000 A

Figure 17 - Voest-Alpine (Austria) hot cathode principle for currents up to 8,000 A

Figure 18 - Principle of transferred arc ignition