Comparative study between Cu and CuCr electrode using two-dimensional particle density image over vacuum arc discharge

The development of high-capacity vacuum circuit breakers requires the fundamental understanding of the dependence of vacuum arc behaviours on electrode materials. Here, the vacuum arc behaviours are strongly dependent on two-dimensional electron and metal vapour densities over vacuum arc discharges. Therefore, direct diagnosis of these particle densities over vacuum arcs is quite important. However, almost all particle density measurements have been conducted using only Cu electrodes and few experimental results are available in literature about correlation between vacuum arc properties and electrode materials. In this study, we performed 2-dimensional electron density imaging over vacuum arcs generated between Cu electrodes and CuCr (Cu75:Cr25wt%) electrodes.