Effect of Mn/Ti Surface Treatment on Voltage Holdoff Performance of Alumina Insulators in Vacuum

摘要

The treatment of the surface of an alumina insulator with a Mn/Ti coating significantly increases its voltage holdoff capability. Insulators treated with this coating had vacuum holdoff voltages about 25% higher than did untreated insulators. During processing (quasimetallizing) the coating penetrates into the alumina; thus, it is fairly insensitive to damage by abrasion or electrical breakdown. The quasimetallized coating is also compatible with subsequent metallizing and brazing of the alumina insulator. It is concluded that the coating decreases the surface resistivity of the insulator, decreases the secondary electron emission yield of the insulator and makes the surface of the insulator dielectrically more uniform. (ERA citation 03:037887)