Consider also the vortex water-wall arc lamp, in which the cooling water (deionized, so that it is a very poor conductor) runs inside the quartz tube. It is swi

Consider also the vortex water-wall arc lamp, in which the cooling water (deionized, so that it is a very poor conductor) runs inside the quartz tube. It is swirled so that there is a gas-filled space along the axis, through which the electric current flows[1]. I have seen powers up to 100MW mentioned. I recall reading somewhere that David Letterman wanted to use one on his show to melt a small car, but the manufacturer thought it frivolous and did not cooperate. [1] https://www.researchgate.net/publication/280621958_Modeling_of_a_Vortex_Water-Wall_Argon_Arc_Lamp_for_Rapid_Thermal_Annealing_Applications#pf1 https://www.researchgate.net/publication/280621958_Modeling_...