Change in the pulse regime of negative corona in air due to a small adjunct of SF/sub 6/

Corona discharge studies were continued concerning the effect of small amounts of SF/sub 6/ in air. Further observations made on sequences of pulses are reported. Analysis made on each pulse sequence have unraveled distinct repetitive features by the pulse regimes. For air, where the distribution of the pulse amplitudes of the Trichel pulse train is normal in form and the variation in pulse amplitude is relatively small, a good correlation between the pulse magnitude and the time interval preceding the pulse under consideration is found to exist. For the air containing 1% SF/sub 6/, the pulse amplitude variations are much greater than for air only, frequently with the large intensity pulses followed by lower intensity ones: this translates into relatively large time interval variations as well. A reasonable correlation is found between the pulse magnitude and both of the preceding and the succeeding pulse time intervals. The significant parameters determining the pulse sequence, and therefore characteristic of the gas under test, are found to be the pulse amplitude, ratio of the large pulse to succeeding pulse amplitude and associated pulse time interval.