Cathode spot velocity in tangential magnetic field on cathode of copper-chromium composition in vacuum

The paper presents measurement results for cathode spot (CS) velocity V under action of a tangential magnetic field on a clean surface (refined by preceding arcing) of the cathode made of cupper-chromium (CuCr30) composition in vacuum. Measurements were performed in the range of currents I = (30-250) A in arcs of different lengths, h = 2 mm and 4 mm. The induction of tangential magnetic field varied in the range B = (0.02-0.15) T. The dependence of the CS velocity on the magnetic field induction was found to be linear: V = KB. The constant K depends on the arc current for currents I <; 2I₀. (where I₀ is the current per spot at B = 0). The maximum value of K (at I > 2I₀) depends on the arc gap length. These results are similar to the results obtained for CS on cathodes made of pure metal, but are at variance with the result of the work by Y.H. Fu (1990) for the CuCr25 cathode. The obtained results are compared with similar results obtained previously in the experiments with different pure metals: Cu, Mo and W.