During a high-current vacuum interruption

the vacuum arc process is mainly dominated by the anode phenomenon

especially the anode spot phenomenon. Formation of a vacuum arc anode spot restricts the success of the vacuum interruption because formation of the anode spot often induces anode surface heating

melting or even evaporating

which crucially influences the thermal characteristics of the anode and determines the post-arc recovery process of the dielectric. The purpose of this paper is to investigate the anode surface temperature at current passing zero after appearan

ce of a vacuum arc anode spot. Experimental results show that after anode spot appearance the anode surface temperature at current passing zero moment（T0anode）is almost independent of the arc current and the opening velocity

but tends to a stable range. The temperature range is 1 600

1

800 K for the contact material CuCr25. External axial magnetic field facilitates the restriction of fluctuation of the temperature T0 anode. In addition

different contact materials have different ranges of T0 anodee.g.

the ranges of T0 anodefor Cu and CuCr50 are 1 800

1

900 K and 1 700

1

800 K

respectively.