The Aging Effect of Surface Flashovers on Insulator Surface in Vacuum: A Case Study

Surface flashover, an extensively studied failure mechanism in high voltage engineering, presents challenges due to its stochastic nature and the lack of a universally applicable theory for various materials and geometries. This article investigates the impact of successive surface flashovers in high vacuum on the performance of an exquisite assembly of cathode, dielectric, and anode made of molybdenum, MACOR®, and, stainless steel, respectively. The findings challenge the prevailing belief favoring gentle conditioning over intense flashover conditioning. High-speed data acquisition is employed to detect rapid transients generated by these discharges and assess the performance. Additionally, the experiment measures voltage and cathode current while also monitoring and analyzing changes in pressure and video throughout the study. Laser profilometry and Auger electron spectroscopy are utilized to establish connections between the physicochemical evolution of the samples and the occurrence of flashovers.