Axial motion of magnetically driven rotating arc

Summary form only given. Electrode erosion in a high power arc is a limiting factor in developing more powerful gas heaters, plasma sprayers and other high current arc systems. The standard method of decreasing electrode erosion is to force the arc attachment to move in the azimuthal direction. This is done either by imposing an axial magnetic field or by rotating gas flow. Another method is suggested for further spreading the electrode heat load and thus to further reduce erosion. One or a few current carrying cables are located along the axis outside the concentric arc electrodes. These cables produce a tangential magnetic field in the inter-electrode gap, which has different directions at different azimuthal angles. Interaction of this field with the radial arc current causes the arc column to oscillate and slowly drift in the axial direction thus spreading the thermal and erosion load of the electrodes.