Formation stages of pulsed discharge in oxygen and carbon tetrafluoride

Abstract

This paper reports the current and voltage oscilloscope waveforms of a pulsed discharge measured in a broad range of frequencies (from 20 to 300 kHz) and duty cycle from 0.15 to 0.85 for two values of oxygen and carbon tetrafluoride pressure values of 0.1 and 1 Torr. Current oscilloscope waveforms of the glow pulsed discharge have been found to possess a plasma phase and an afterglow phase. The following stages of the plasma phase have been observed: 1. The capacitive current pulse of about 0.5–1 μs in duration; 2. The current growth stage the duration of which depends on the gas species, the plasma phase duration and the pressure; 3. The plateau (remarkably pronounced only for carbon tetrafluoride and absent for other gases); 4. The current decrease of tens microseconds in duration down to the level corresponding to that of the direct voltage discharge.