power that exits the torch and enters the process”. Thermal plasma DC torches, non-transferred arc, hot cathode In a DC torch, the electric arc is formed between the electrodes (which can be made of copper, tungsten, graphite, silver etc.), and the thermal plasma is formed from the continual input of carrier/working gas, projecting outward as a plasma jet/flame (as can be seen in the adjacent image). In DC torches, the carrier gas can be, for example, either oxygen, nitrogen, argon, helium, air, or hydrogen; and although termed such, it does not have to be a gas (thus, better termed a carrier fluid). For example, a research plasma torch at the Institute of Plasma Physics (IPP) in Prague, Czech Republic, functions with an H2O vortex (as well as a small addition of argon to ignite the arc), and produces a high temperature/velocity plasma flame. In fact, early studies of arc stabilization employed a water-vortex. Overall, the electrode materials and carrier fluids have to be specifically matched to avoid excessive electrode corrosion or oxidation (and contamination of materials to be treated), while maintaining ample power and function. Furthermore, the flow-rate of the carrier gas can be raised to promote a larger, more projecting plasma jet, provided that the arc current is sufficiently increased; and vice versa. The plasma flame of a real plasma torch is a few inches long at most; it is to be distinguished from fictional long-range plasma weapons. Gallery See also Plasma (physics) List of plasma (physics) applications articles Plasma source References Plasma physics Plasma processing Sustainable technologies