Arc velocity and cathode erosion rate in a magnetically driven arc burning in nitrogen

Measurements of the arc velocity and of the erosion rate are reported for a Cu cathode. The 100 A arc, burning in N, is given by a magnetic field B, varying from 5.1 to 171.0 mT, between concentric Cu electrodes having an inter-electrode gap of 4 mm. The arc velocity varied with B exp 0.60 throughout the range investigated. The erosion rates dropped from 9.0 to 1.0 mu g C exp --1 as the arc velocity was increased from 15 to 135 m s exp --1 . 25 ref.--AA