Electron swarm parameters in gas mixtures of CF3I, SF6, CO2 with N2 at atmospheric pressure

This paper presents the insulation characteristics of gas mixture containing CF₃I as an alternative to SF₆ from the view point of electron swarm parameters. The electron swarm parameters including electron attachment and multiplication, electron drift velocity and the effective ionization coefficient were investigated both experimentally and numerically in gas mixtures of CF₃I, SF₆, CO₂ with N₂ at atmospheric pressure. In the experiment, weakly-ionized plasma was generated between a quasi-uniform field gap by pulse laser irradiation in test gas, and the electron drift velocity and the effective ionization coefficient were estimated from the electron current waveforms at various electric field strength. In addition, the measured results were compared with numerical results calculated by means of Monte Carlo Simulation. As a result, the measured result of electron drift velocity was in good agreement with calculated one. It was revealed that dilute CF₃I in N₂ had a strong electron attachment effect as well or better to dilute SF₆ in N₂ at atmospheric pressure.