Experimental Study of Vacuum Arc Characteristics of Cu-Cr Alloy Electrode Recorded by Various Wavelength Bandpass Filters

The objective of this paper is to study the density and spatial distribution characteristics of different particles in the vacuum arc of Cu-Cr alloy electrodes. In this paper, the density and distribution characteristics of different species in the CuCr25 vacuum arc before and after the appearance of anode spots were studied by using high-speed cameras and filters with central wavelengths of 450 nm, 500 nm and 530 nm. The CuCr25 cupshaped axial magnetic field (AMF) contact was selected, and the current was set to 18 kA and 24 kA (rms). The results indicate that, before the appearance of anode spots at the arc current of 18 kA rms, the arc plasma is mainly composed of Cr I, Cr II and Cu III. The density of Cu I and Cu II is less, and the density of Cu I and Cu II near the electrode surface is much higher than that in the electrode gap. Within 1 ms before the current crosses zero, the density of Cr I, Cr II and Cu III is higher than that of Cu I and Cu II. Moreover, after the anode spot appears, the ion density near the anode, near the cathode and in the interpolar space increases. And within 500 μs before the current crosses zero, Cr I, Cr II and Cu III are mainly concentrated near the cathode and anode surface, and Cu I and Cu II are mainly concentrated near the cathode.