Control and Propulsion of an Atmospheric Pressure Plasma Ring

Convoluted Arc With Flux Concentrator for Current Interruption

“…These values compare with a Lorentz force of 4.9kN/m within the annular arcing space (R2 and R1, Fig. 4) for the same peak current of 15.8kA reported by Shpanin et al [11] without a flux concentrator. Thus it is theoretically predicted that a flux concentrator of inner radius 7.0cm would produce a 10% increase in the Lorentz force.…”

“…An indication of the amount of such ablated material can be obtained by measuring the shape of the inner PTFE cylinder surface before and after arcing. Such tests [8] show that the PTFE material erosion was mainly concentrated half way axially along the coil axis where the Lorentz forces were also a maximum. A Lorentz force of 5kN/m, with an half cycle of 50Hz A.C. peak current of 14kA, produced 53mm 3 ablated material [8], so that an extra Lorentz force of 496N/m (Table I, Appendix II) could potentially produce an extra 5.3mm 3 of ablated material.…”

“…Such tests [8] show that the PTFE material erosion was mainly concentrated half way axially along the coil axis where the Lorentz forces were also a maximum. A Lorentz force of 5kN/m, with an half cycle of 50Hz A.C. peak current of 14kA, produced 53mm 3 ablated material [8], so that an extra Lorentz force of 496N/m (Table I, Appendix II) could potentially produce an extra 5.3mm 3 of ablated material. This in turn could reduce the reliance upon the arc quenching capability of the surrounding gas.…”

“…It has been shown experimentally [8] that at the axial location at which the axial Lorentz force (F) is theoretically a maximum, the radius of the inner PTFE cylinder suffers a maximum reduction due to ablation of the PTFE.…”