Electrode erosion and lifetime performance of a high repetition rate, triggered, corona-stabilized switch in air

This paper describes the work undertaken to investigate the electrode erosi on mechanisms and lifetime-limiting parameters of a sealed, high pulse repe tition frequency (PRF), triggered, corona-stabilized (TCS) switch. The swit ch, which had a rod-plane geometry, was filled with air and operated at rep etition rates of 10 Hz and 1 kHz. The erosion rates of anode-cathode electr ode materials such as brass, stainless-steel, aluminium and elkonite were m easured, and their surface conditions were studied optically and photograph ed. The experimental results presented reflect the different mechanisms res ponsible for the erosion of the rod (anode) electrode of the TCS switch, wh en operated at a PRF of 10 Hz and 1 kHz. The erosion of the anode electrode at a PRF of 10 Hz varied from 5.44 x 10(-6) cm(3) C-1 for elkonite to 17.3 7 x 10(-6) cm(3) C-1 for aluminium. Additionally, at a PRF of 1 kHz, anode erosion ranged from 9.82 x 10(-6) cm(3) C-1 for brass to 16.58 x 10(-6) cm( 3) C-1 for elkonite. Cathode erosion rates as high as 36.6 x 10(-6) cm(3) C -1 for brass at 10 Hz and 19.55 x 10(-6) cm(3) C-1 for elkonite at 1 kHz we re measured. The lifetime of the TCS switch was found to be inversely propo rtional to the erosion rate of the rod electrode. Additionally, gas deterio ration and anode surface conditions were found to have a pronounced influen ce on the performance and operational behaviour of the TCS switch.