Investigations of arc instabilities in DC vacuum arcs

Investigations of low currents vacuum arcs (< 30 A) have been performed on CuCr, Cu and W contact materials in order to evaluate their chopping current behavior. Results show that the arc burning between CuCr contacts is relatively stable with an average lifetime of 16 ms at 7A, in the presented test set-up. On the other hand, Cu and W contacts are less stable and more predisposed to current ch...