Spectrum Analysis for Vacuum Surface Flashover of Different Insulator Materials

The optical diagnostic method can provide much more information about the physical process of surface flashover. In this paper, the vacuum surface flashover spectra of five different insulator materials (including both organic and inorganic insulator materials) under pulsed excitation are presented. According to the spectrum analysis results, many molecular spectral bands emerge in the spectrum of surface flashover as well as the atomic lines. The flashover band spectra of different insulators are nearly the same, most of these band spectra might be generated by ionized gases which are desorbed from insulator surface. Besides, some of the atomic lines are identified to be emitted by material element, which implies that the material was decomposed during the flashover process, and the decomposed material together with desorbed gas contribute to the final stage of flashover.