Direct current arcs

Thermal plasmas - production

Figure 1 - Changes in electrical conductivity of different plasma gases (Ar, Ar-H2 (25% vol) and N2) as a function of the enthalpy h of the gas at atmospheric pressure

Figure 2 - Principle of radio frequency coupling

Figure 3 - System of cooled copper fingers used in high-power radio frequency torches (≍ 1 MW) for simulating the reentry of a spacecraft

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

Figure 5 - Voltage distribution in a direct current argon arc

Figure 6 - Principle of blown arcs

Figure 7 - Principle of transferred arcs

Figure 8 - Operation of a hot cathode torch

Figure 9 - Principle of a hot cathode torch used in projection

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

Figure 11 - ® Plazjet Torch Hot cathode button type with vortex gas injection

Figure 12 - Diagram of the Aerospace torch [16] [24]

Figure 13 - Diagram of the Westinghouse torch

Figure 14 - Diagram of the SKF torch

Figure 15 - Transferred arc

Figure 16 - Principle of a Tetronics (UK) hot cathode for currents up to 8,000 A

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

Figure 18 - Principle of transferred arc ignition