We calculated the uniform dielectric breakdown field strength of residual 30%CF_3I/CO_2 gas mixtures during the arc extinction process over the temperature range 300–3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function(EEDF), which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend(SST) condition. During the insulation recovery phase, the hot CF_3I/CO_2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction(90.3 Td, 1 Td=10-21V·m2)is only 38% of the original value before arc(234.9 Td). The adverse insulation recovery ability of CF_3I/CO_2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.
Ion parameters in electron cyclotron resonance （ECR）microwave plasma were measuredby ion sensitive probe and were compared with the electron parameters obtained by doubleLangmuir probe.The effects of gas pressure and microwave power on the ion temperature anddensity were analyzed.The spatial distribution of the ion parameters was also investigated bythe ion sensitive probes with a tunable radial depth installed on different probe windows alongthe chamber axis.Results showed that the ion density measured by the ion sensitive probe wasin good agreement with the electron density measured by the double Langmuir probe.The influenceof gas pressure on the ion parameters was stronger than that of microwave power.With theincrease in working pressure,the ion temperature decreased monotonously with a decreasing ratelarger than that at higher pressure.The ion density first increased to a peak (42.3×1010cm-3)at f Pa and then decreased.The ion temperature and density increased little with the increasein the microwave power from 400 W to 800 W.The plasma far away from the resonant point isfound to be radially uniform.
