Electrode area of breakdown depending on conditioning mechanism under non-uniform electric field in vacuum

In this paper, we discussed the breakdown (BD) area of electrode on conditioning characteristics under non-uniform electric field in vacuum. Negative standard lightning impulse voltage was applied between rod and plane electrodes made of Cu-Cr and stainless steel for different tip radii and gap lengths. Experimental results revealed how the electrode area of BD and the BD field strength depend on the electric field distribution and the electrode materials in the conditioning process. As a result, we quantitatively clarified the relationship between electrode area of BD and conditioning mechanism under non-uniform electric field in vacuum.