An investigation of the lifetime of high PRF triggered corona stabilised (TCS) switches

The lifetime limitation of a high pulse repetition frequency (PRF) triggered corona stabilised (TCS) switch, with electrodes made from brass, stainless steel, aluminium and elkonite, have been investigated. The switch, which had a rod-plane configuration, was filled with air at a pressure of 3.0 bar and operated at a PRF of 10 Hz. The erosion rates of the anode and cathode materials were measured, and the surface conditions of the electrodes were studied optically and photographed. Anode erosion rates varied from 5.47 /spl mu/cm/sup 3//C for elkonite to 17.8 /spl mu/cm/sup 3//C for aluminium, while cathode erosion rates as high as 37.1 /spl mu/cm/sup 3//C for brass was measured. The lifetime of the TCS switch was found to be directly proportional to the erosion rate of the rod electrode (anode), and with elkonite, it was projected to be higher than 1/spl times/10/sup 6/ shots. Additionally, gas deterioration and anode surface conditions were found to have pronounced influence on the performance and operational behaviour of the TCS switch.