Optical spectroscopy studies of argon in partial vacuum high frequency pulsed voltage

Abstract

Power devices and systems operating in partial vacuum are susceptible to partial discharges, corona, or volume discharge1. In most cases, it is important to understand the characteristics of the discharge such as the space-charge distribution, the electron energy distribution, and collision processes in which the species are involved. Spectroscopic study of the discharge is one of the most common used methods of obtaining such information2. In this paper, the breakdown characteristics for Argon are studied in partial vacuum of 100 milliTorr to 5 Torr. A unipolar pulsed signal is applied to the parallel plate and point-plane electrode configuration3. The frequency is varied from 10 kHz to 100 kHz with a fixed duty cycle of 50%. Current voltage and optical spectroscopic data of the argon discharge were collected as a function of time. The spectra of the light emission is time resolved with a 1ms time resolution and consecutive frames. From this series of data, the time variation of the intensities for dominant lines in the spectra lines was studied. The results of the analysis help to understand the collision processes involved in the plasma formation for the pulsed breakdown at kHz frequencies.