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

Abstract

This paper describes the work undertaken to investigate the electrode erosion mechanisms and lifetime-limiting parameters of a sealed, high pulse repetition frequency (PRF), triggered, corona-stabilized (TCS) switch. The switch, which had a rod-plane geometry, was filled with air and operated at repetition rates of 10 Hz and 1 kHz. The erosion rates of anode-cathode electrode materials such as brass, stainless-steel, aluminium and elkonite were measured, and their surface conditions were studied optically and photographed. The experimental results presented reflect the different mechanisms responsible for the erosion of the rod (anode) electrode of the TCS switch, when 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 × 10-6 cm3 C-1 for elkonite to 17.37 × 10-6 cm3 C-1 for aluminium. Additionally, at a PRF of 1 kHz, anode erosion ranged from 9.82 × 10-6 cm3 C-1 for brass to 16.58 × 10-6 cm3 C-1 for elkonite. Cathode erosion rates as high as 36.6 × 10-6 cm3 C-1 for brass at 10 Hz and 19.55 × 10-6 cm3 C-1 for elkonite at 1 kHz were measured. The lifetime of the TCS switch was found to be inversely proportional to the erosion rate of the rod electrode. Additionally, gas deterioration and anode surface conditions were found to have a pronounced influence on the performance and operational behaviour of the TCS switch.